Printed by David Syme &: Co. Limited. publisher of "TliO AK e," 233 Collins Street. Melbourne. C. l. AVIATION

SAFETY. DIGEST Editorial

D .e pa r· t me n ·t of Ci vi I Aviation Australia No. 45 MARCH, 1966 WINTER WEATHER WISE

Contents Once again we are on the threshold of a season when we must expect weather conditions to complicate to some extent the operation of light aeroplanes. Days will be shorter, low cloud and poor visibility more in evi­ Editorial 1 dence, weather conditions generally less predictable and less favourable to VFR flight, air temperatures will be more conducive to engine icing, and Fire in Flight 2 frost will form on aircraft left standing overnight in .the open. None of Secure that Oil Cap 5 these problems Of winter flying need be particularly hazardous in them­ selves but if we do not make allowances for them and if they catch us Don't Forget the Chocks 6 unprepared, they can compound, more easily than summer flying condi­ Negligence in Refuelling Destroys Helicopter 8 tions, to set the stage for an accident. Cessna 185 Destroyed 10 Some aspects of winter weather operations are mentioned in this issue Overshoot Leads to Overturn 11 of the Digest; other problems are to be discussd in our June issue. But the one potentially most dangerous has already been discussed at some length Stall During Forced Landing 12 in previous issues. The situation arises when pilots not qualified for instru­ Some Radio Difficulties 13 ment flight press on into deteriorating visibility, often at low altitude, to the point where visual reference is finally lost altogether and the pilot Do You Remember 14 either lose,s control of his aircraft and it dives into the ground, or the Cabin Heaters and Carbon Monoxide - 16 aircraft simply collides with obs.tructing terrain. Two years ago, four Australian Tuna Fisheries accidents of this type occurred within a period of six weeks and cost the Cessna 337 seen against the back­ Fatal Fire in Wheel Brakes 18 ground of the Company's fishing lives of eight persons. These accidents prompted the Director-General to vessels at sea south of Eden, New South Wales. The security af­ Be Alert for Carburettor Ice 20 write personally to all light aircraft pilots, and all four accidents were forded by the aircraft's two subsequently reported in th~ Digest. engines, coupled with th e excel­ Oxygen Equipment Explosion 22 lent downward visibility offered by its high wing, makes the air­ Your New Handbook 23 Last year, it seems, pilots were much more on their guard against be~ng craft very suit able for deep sea caught in similar weather conditions, and there were no accidents in Aus­ t.una spotting operations off the Comet Strikes Ground During Approach 24 cont inental shelf of south-eastern tralia arising directly from this cause. But man forgets and it might well and southern Aust ralia. Lost and Found 25 be that some pilots has already forgotten the tragic lessons at Burketown Ballarat and in the Adelaide hills. So let any who are inclined to be scepti­ Is Your Windscreen Clean? 26 cal first look again at the circumstances common to all these accidents Water in the Fuel ? 28 and ask themselves how they would have reacted. Air Sense - 28 Then let each of us go about our flight planning and operations in the coming months, determined that they shall be accident-free, and that winter fl ying conditions will not find us wanting in flight prepara~ion or airmanship. Aviation Saf ety Digest i s prepared in the Air Safety Investi gation Branch and published quarterly . Enquiries and contributions f or publication should be addressed to The Editor, Aviation Safety Digest, D epartment of Civil Aviation, Box 1839Q, P.O., Elizabeth Street, MELBOURNE, C .1.

Except f or that material which is i n dicated to be extracted from or based on another publication, i n which case t he authority of the originator should be sought, the material contained herein may, with acknowledgment, be freely re­ produced in publications int ended primarily for ci rcul ation in t he Aviation I ndustry. All other publication, w hether by the print ed word, radio, or t elevision, must have the prior approval of the Department of Civil Aviation. MARCH, I 9 6 6 so the first officer isolated the must be landed in the shortest Seeing that the engine fire was bell, and at the captain's request, possible time, the captain closed still well alight and that the fire advised Melbourne that the air­ the throttles, selected the under­ crew were playing foam over the craft had an engine on fire and carriage and flaps down, and in­ port side of the aircraft, the first they would divert to Mangalore, structed the first officer to com­ officer opened the starboard rear whi:ch was some 30 miles closer plete the pre-landing checks. The door, placed the escape chute in than Melbourne. captain reduced speed to 135 knots, position and opened the three star­ and ·banked the aircraft steeply board emergency exits on to the As the aircraft was being pro­ into a minimum distance left cir­ wing. The captain came down gressively stepped down by Mel­ cuit for runway 23. It was 1906 from the cockpit, left the aircraft bourne Control, the senior hostess hours as the aircraft touched by climbing down the side of the reported more sparks coming from down. escape chute to check briefly with the engine. The first officer went As soon as the captain had the fire crew, then ordered the back to the passenger cabin to braked the aircraft to a halt on passengers to leave their hand lug­ visually check the No. 1 engine the runway, he ordered the three gage behind and evacuate the air­ but there was no indication of fire. live engines feathered, the flaps craft. While the captain supervised He returned to the cockpit and the retracted to the 32 degrees position the passengers leaving via the crew ·completed the descent check to facilitate evacuation of passen­ chute, the first officer assisted list. At 6,000 feet, the aircraft ar­ gers over the wing, and requested others out through the over-wing rived over the Mangalore N.D.B. the first officer to supervise the exits and down on to the ground. in cloud, and the captain began a evacuation of the passenger ca;bin. The three hostesses were the last descending turn with the intention The captain remained in the cock­ to leave the aircraft and the cap­ of intercepting· the north-eastern pit to ·complete the emergency tain directed them to group the leg of the V.A.R. At 4,500 feet, still "engine fire on the ground" drill. passengers together 100 yards be­ in cloud, the engine fire became Meanwhile, the previously alerted hind the aircraft. He and the first visible from the cockpit as a bril­ Mangalore fire crew had taken up officer then obtained a ladder from liant white glow increasing rapidly their fire-fighting positions near the fire crew and climbed back into in intensity. Glowing pieces of the blazing engine and were con­ the aircra'ft to ensure everyone was metal and showers of sparks fining the fire to the nacelle with out. The first officer turned off the streamed back from the en­ a covering of foam over the port master power switch and the cap­ gine and the fire seemed to wing and fuselage side. The fire tain informed the senior fireman be enveloping the wing. At crew had correctly assessed that that the aircraft evacuation was 4,000 feet the aircraft broke the fire was being fed by •burning complete. While a Viscount 832 was en route from Canberra to Melbourne on a regular public out of cloud two miles aibeam the magnesium, and were withholding Using dry powder and carbon transport flight on 4th August, 1965, an uncontrollable fire developed in the No. 1 engine. south-western end of Runway 23 . any attempt to extinguish it until dioxide, the fire crew then attacked The captain diverted to Mangalore, Victoria, where an emergency landing was made in the Deciding that an extreme emer­ every one was safely out of the the main fire. in the engine. It was dark with all emergency services standing by. Thanks to the actions of the flight crew and the gency existed and that the aircraft aircraft. quickly contained •but the engine efficiency of the fire crew, the intense fire was confined to the engine nacelle and all Fig 1. T he intermediate casinfl completely burnt away, exposing the damag.ed cowlings had to be removed before occupants were able to evacuate the aircraft safely. com pressor shaft and auxiliary drive gear trains. the extinguishent could penetrate to the source of the fire, the burn­ ing magnesium intermediate cas­ ing of the engine. A secondary fire The Viscount had departed from peller noise occurred again. As ing. The captain called for the fea­ was burning in the nacelle behind Canberra at 1800 hours Eastern the aircraft swung to port the thering drill and crew identified the fire wall and the captain used Standard Time with a crew of five second time, the first officer saw and shut down the No. 1 engine. an axe to cut holes in either side and 38 passengers. The flight pro­ the No. 1 feather light flicker and The captain was using the wing of the nacelle to allow the fire ceeded uneventfully until soon the No. 1 turbine gas temperature inspection light to visually check crew to reach it . It was put out after the aircraft had passed the gauge raipidly decrease to 850°c that the propeller had feathered almost immediately but the main Kelly reporting point, 86 nautical from the rubnormally high indica­ when the senior hostess reported magnesium fire ·could not 1be fin­ miles north-east of Melbourne, but, tion of 900°c. In cruising flight, the sparks were coming from the en­ ally extinguished until pieces of at 1843 hours, just as Melbourne turbine gas temperature indication gine. A few seconds later the No. the burning magnesium alloy had Control was acknowledging the is normally about 730°c. At the 1 engine fire warning came on and been raked out on to the ground aircraft's position report, the air­ same time, the first officer noticed the fire warning bell began ringing. and a layer of foam used to craft without warning yawed vio­ the engine torque pressure gauge The captain called for the "engine smother what fire remained in the lently to port with the noise of a fluctuating between 60 and 90 fire in flight" drill and the engine. rapidly coarsening propeller. The pounds per square inch. Normal first officer fired the No. 1 fire It was found that the engine first officer uncoupled the auto cruise torque pressure is around 220 extinguisher bottle while the cap­ fire had been sustained principally pounds per square inch and the pilot and the captain took control tain reduced airspeed to 150 knots. 1by combustion of the magnesium but just as suddenly the yawing· propeller auto-feathers at 50 The fire warning continued and ceased and the aircraft swung pounds per square inch. after 45 seconds the second bottle alloy intermediate casing, which back to its original heading. A few Again the yawing ceased and for No. 1 engine was fired. Still was almost completely destroyed. seconds later the yawing and pro- the aircraft returned to its head- the fire warning system operated, (Fig. 1). Residual fuel in the low

2 AV I AT I 0 N SA FE TY D I GEST MARCH, 1 9 6 6 3 pressure fuel line, and engine oil cockpit. The fire warning system occupants, and fo r the sound judg­ tinguisher systems. Technological he would recommen d delaying posi­ must be extremely sensitive to as probably also contributed to the would have been triggered by the ment and concern for safety shown effort is constantly being expended tive fi re control action, pen ding many manifestations of fire as pos­ intensity of the fire. Incandescent detector mounted on the engine by the Mangalore fire crew, what to increase the reliability of these physical evidence in the form of sible. This makes the problem of breather pipe while the actual fire amounted to no more than an air flames or smoke ? From the fi rst discrimination most difficult. Tech­ magnesium falling from the burn­ systems, but infallibility is still a was still confined within the en­ safety incident could instead have long, long way ofI .. . report of fire to the final catas­ nical effort and research is con­ ing casing had burned a large hole gine. Under these circumstances, easily been a major aircraft disas­ "In 1959 the eight-man crew of trophic crash, his last adventure stantly striving to eliminate the in the underside of the engine cow­ the external fire extinguishing ter. a Neptune perished when the air­ took only slightly longer than one false warning but it will never be ling (Fig. 2), but the rest of the system could not be immediately Secondly, the incident has a vital craft crashed while attempting an minute thirty seconds. entirely successful. cowling was intact though buckled effective. word to say about fire warnings. emergency landing near Richmond, "Noth ing in this life is infal­ "False fire warnings amount to by heat. The fire behind the bulk­ The two instances of the aircraft Because false fire warnings occur New South Wales. In those days, Uble, and yet, to be effective, a fire 'fail-safe' protection only so long head had been burning in two suddenly yawing to port, which far more frequently in aircraft although fitted with a fire warn­ warning system must •be as close as the aircraft captain treats every places. Electrical insulation had were the first indications of trowble, than do actual engine fires, there is ing system, Neptune aircraft had to it as possible. If it is to fail, it warning as a real one. If he is · ignited from radiant heat, and were determined to have been a tendency for crews to discount no fire extinguisher system fitted. should fail safe. Of the two failures prepared to wait for more spec­ waste oil lying in the base of the caused by the No. 1 propeller auto­ cockpit fire warnings as "false," if If the captain of that aircraft possible, it is preferable to have a tacular evidence of fire before tak­ engine cowling had ibeen set on feathering. A strip inspection of the they cannot see any visual indica­ could be asked today what advice warning where no fire exists on ing positive action, a fire warning fire by hot gas and magnesium par­ propeller revealed no evidence of tion of fire. The R.A.A.F. are also he would offer other pilots faced occasions, than to have a fire, system is useless." ticles coming from the engine any malfunction and the auto­ very concerned with this attitude with a fire warning in flight, is where no warning is given . To And, we could a dd, his first breather pipe. The engine fire had feathering process was probably in­ by crews and the problem is dis­ there a ny question as to what that ensure the highest possible relia­ "real" warning is likely to be his been extinguished before it could itiated by a fall in lubricating oil cussed in some detail in a recent advice would be ? Is it possible that bility in detecting a fire, the system last ! damage the airframe structurally. flow to the torque meter pump, issue of the R.A.A.F.'s "Flight Di­ resulting in the engine torque pres­ gest.'' Some of their comments are A detailed examination of the sure indication momentarily falling extremely pertinent to this aspect damaged engine after it had been below the auto-feather setting. of the Viscount fire and we have removed from the aircraft, dis­ been given the R.A.A.F.'s permis­ closed a failure of the rear com­ COMMENT sion to quote them- SECURE THAT 01 L CAP pressor bearing. Metal from the In the first place, the incident "Fire in the air is not a com­ failed bearing had contaminated manifests the worth of team effi­ mon occurrence in modern air­ the engine oil scavenge filters and ciency and sound training in craft, but it does occur, and not Only a little item in a pre-flight inspection -but how important! Yet, even the most the main pressure filter. Cracks dealing with emergencies of this as infrequently as we should hope. fastidious pilots can be caught out - as witness this incident: in the flame tube air cases, the nature. Had it not been for the way Recognition of this continuing Before beginning a cross-country flight from Sydney to an aerodrome on the western flame tube support lugs and the in which the aircraft crew handled hazard to aviation is reflected by side of the Great Dividing Range, the pilot of a Cessna 210 carried out his daily inspection failure of an oil cooler mounting the situation in getting the air­ the inclusion in even the most while he waited on the apron for the refuelling tanker. When it arrived, one attendant set lug indicated that the engine had craft safely on to the ground in modern aircraft, of highly sensitive about refuelling the aircraft while the other proceeded to top up the engine oil. He removed been subjected to high vibration. the least possible time and organ­ fire warning systems, and costly, the oil cap, produced quart tins of oil ,and prepared to pour them into the oil filler neck. Mechanical damage to the •blades izing the safe evacuation of all complex, highly efficient fire ex- The attendant had omitted to bring a funnel, and because the filler neck is located some of the second stage compressor, four inches below the top of the cowling, the pilot refused to allow him to pour the oil in the bearing air seal and the teeth without one. The pilot re-checked the oil level and after finding it adequate, told the attend­ of the gears in the auxiliary drive Fi g. 2. Heat damage to the engine cowlings. I n candescent magnesium f alling ant that he would not require additional oil. gear train, suggested that the fail­ from the i nt erm ediate casing burnt the large hole in the l ower cowl. ure of the rear compressor bear­ Turning then to the other attendant who hod finished the refuelling in t he meantime, ing had been the primary failure, the pilot climbed up to see that both fuel tank caps had been properly secured before check­ permitting the second stage com­ ing the tanks for water. By the time the pilot had done this, both the engine oil cap and pressor shaft to move forward until the oil filler access panel in the engine cowling had been replaced, but because the men were the turbine to compressor spline now urging him to sign for the fuel, he didn't re-open the cowl to check the security of the drive became disconnected. oil cap. Instead he made a brief visual inspection through an air intake in the front of the cowling, saw the cap in place and was satisfied. There was no evidence to sug­ As soon as the tanker had driven away, the pilot climbed aboard, started the engine and gest that the engine fire had been taxied out. The run-up was normal, and he took off, but at about 200 feet, oil streamed started by torching emitted from from the engine cowling and over the windscreen. The pilot turned back and landed, taxied the combusion chambers, and in, and opened the cowling to inspect the engine. The oil cap was loose, allowing oil to be there was little doubt that the fire forced out of the neck and over the engine. had originated from over-heating of the failed compressor bearing. The hour that it took to clean up the mess sufficiently for the flight to continue, prob­ The bearing had obviously 1been ably seemed a high price to pay for the few seconds saved in the pre-flight inspection. But extremely hot and had proba:bly how incomparably higher it could have been if the oil cap had come off a little later when ignited its lubricating oil. Once the aircraft would have been crossing the Divide! started, the fire would have been This incident happened because the pilot was distracted while carrying out his pre-flight fed with _air from the failing ad­ routine. It is a well-substantiated fact that interruptions of this sort duril'l'g vital routine jacent bearing oil seal, and would "drills" and checks, both on the ground and in the air, have helped to set the stage for - have spread from the inside to the many on aircraft accident. A strict personal r.ule not to allow your attention to be diverted outside of the magnesium alloy at such times, and not to be "steam-rollered" into interrupting your set routine, makes for intermediate case, where it be­ safer flying and helps to avoid these "accidents in the making." SAFETY IS PARAMOUNT came visible to the crew from the - LESSER THINGS CAN USUALLY WAIT A MINUTE OR TWO.

4 AVIATION SAFETY DIGEST MARCH, I 9 6 6 s T./ie aircraft with the bent propeller (left) also ran away after being hand started. Its starboard wing collided with the fin and rudder of the aircraft in the foreground, telescoping the tail and fuselage as sho!.!_Jn, while the whirling propeller blades hacked into the port tailplane.

'\)I I 1j ( I// 'I' · r" \,if':

only succeeded in swinging the aircraft broadside to pilot is temporarily denied some of the advantages the wind, which was now gusting between 10 and 20 inherent in a modern aircraft. knots. The aircraft continued to gain speed and the The title of this article ls, of course, sound ad­ pilot rushed for the front cockpit switches, but as vice for pilots who still fly Tigers or Gypsy Moths he flicked them off, a gust lifted the starboard wing, or perhaps ultra-lights not fitted with brakes. But To judge from the accidents that have occurred didn't chock the wheels. After he had refuelled the the aircraft swung down-wind and was blown over it also has something to say to the pilots of the in recent months, starting aeroplanes by hand must modern light aeroplanes, not so much as a literal aircraft, the pilot checked that the throttle was on its back as shown. be an operation absolutely fraught with hazards, not closed, turned on the ignition switches, and walked instruction, ·but as an adage to develop a right atti­ only to the particular aircraft involved, but also to around to swing the propeller. The engine fired after Only a few weeks later, another Tiger ran away tude of mind in all aspects of our flying. Let us anything else that happens to get in the way ! The a couple of pulls and the aircraft started to move in similar circumstances at a station property airstrip be careful that the improvements and comforts built three photographs on this page and the next bear into. todays' aircraft do not make us complacent in forward. The pilot caught hold of t he port wing, but in South Australia. The aircraft, which was parked mute testimony to this thought. our attitude to safety. unchocked on the tarmac in front of the strip's two In some of the cases we have in mind, at least All that remained of a C essna 182 that ran away, after hangars, was to make a local flight. The passenger being hand started, and coralled itself in a cattle stock yard. This DH 82 moved of] unoccupied after being started with­ one of which has already been reported in the Digest . was installed in the front cockpit, the throttle set for out chocks, swung downwind, and was blown over on to (See "An Expensive Mistake," Aviation Safety Digest starting, and the pilot swung the propeller. When its back. No. 40, December, 1964), the aircraft have run away the engine started, the aircraft began to roll forward while being hand-started when, for one reason O!' another, t he brakes failed to hold. and turned towards the hangars where the tarmac sloped slightly downhill. The passenger had the pre­ Air Navigation Regulation 223B clearly defines sence of mind to close the throttle and the pilot the pilot's responsi:bility, during a hand-starting ope­ jumped up and cut the switches, but the aircraft ration, to ensure that "adequate provision is made gathered momentum down the slope, ran 'between the to prevent the aircraft moving forward." It is per­ haps understandable that the pilots of the two mod­ hangars and collided with two posts. Happily the ern aircraft shown did not think to use chocks for a passenger was not injured but this aspect of the hand start that was, for them, a very rare occurrence. accident nevertheless points up the wisdom of the What is difficult to understand is that this "no chocks third condition laid down in A.N.R. 223B. required" thinking is sometimes applied to the sur­ viving representatives of aircraft built in an era when In years gone by when nearly all light aeroplanes chocks were standard equipment for starting-air­ had to be hand started every time they flew, acci­ craft of the type exemplified chiefly today by the dents of this sort were rare. They were avoided Tiger Moth. because the hazards of hand starting were fully recognized, accepted as normal, and proper precau­ Not long ago, in Victoria, a pilot, making a cross­ tions taken. It is paradoxical that today's aircraft, country flight in one of these aircraft, landed at with all their refinements designed to make handling Echuca to refuel. After taxi-ing to the refuelling safer and easier, can promote practices leading to point, he turned into wind and switched off, but an accident where, for some reason or another, the

6 AVIATION SAFETY DIGEST M A R C Ii, 1 9 6 6 7 • Negligence Ill Re-fuelling destroys Helicopter

At Kunanurra, in the Ord River the Jtanding skids dug into the ia pint, were drained into a jar and there was no tmce of water in the district of Western Australia, a muddy, irrigated ground and the were found to consist entirely of aircraft's fuel system at that time. Bell 47 helicopter was engaged in aircraft lurched forward heavily on water. With the aircraft's fuel The drum of fuel from which the spraying cotton crops. Beginning to the cockpit bubble. The whirl­ selector turned on, the fuel filter helicopter had been serviced im­ operations at 0600 local time, the ing rotor blades severed the spl'ay line was drained again and a fur­ mediately before the accident was helicopter completed spraying 340 booms, the hopper tank mountings ther half pint of water was dis­ checked for signs of water, but acres at one farm, then flew on to and the fuselag·e behind the engine, charged before fuel began to flow. n one was found. Further enquiries the next property to refuel and scattering these components over The amount of residual water in then established that, while work­ ing at the first spraying site, the begin working there. a wide area, before the main fuse­ the fuel tanks could not be posi­ helicopter had been refuelled be­ lage section fell back on to the tively determined because one tank The refuelling was carried out by side an irrigation canal, and, with landing skids. Despite the fact had been split open in the crash the operators from 44-gallon drums the refuelling tender parked on a that the cockpit bubble was com­ and the other was lying in a posi­ carried on a utility truck that bridge over the canal, it had been pletely shattered and the cabin tion from which the contents could served as a refuelling tender. After necessary to r un the refuelling hose assembly distorted and buckled, the not be readily drained. It was the helicopter had been refuelled across the canal to reach the air­ pilot escaped with minor injuries. nevertheless clear that there had and the spray tanks reloaded, the craft. The refuelling equipment Investigation of the accident been sufficient water in the tanks pilot took off to begin his first used by the operators consisted of spl'aying run. Fifty yards after established that the engine failure to occupy all the unusuable fuel space and to cover the base of the a quart stroke drum pump to which had been caused by contamination lifting off, while the helicopter was fuel line stand pipes. was attached a 60 feet length of moving forward at about 55 knots, of the fuel system by water. The The aircraft maintenance engi­ one-inch plastic garden hose. On contents of the main fuel filter, 10 feet above the ground, the en­ neer who had carried out the daily completion of the refuelling on this gine back-fired and lost power the fuel line from the filter to the inspection on the helicopter before occasion, the hose had been completely. The pilot tried to flare carburettor and the carburettor it began operations on the morning dropped on the ground and pulled the helicopter for a landing, but itself, aggregating together about of the accident, was certain that back through the canal before being re-stowed on the refuelling This picture was taken from where the helicopter landed for the first refuelling. tender, which was then driven on T he tender was parked as shown, and the refuelling hose was afterwards dragged to th e next refuelling site. It was back through the canal before being replaced on the vehicle. evident that the water had en­ tered and been trapped in the hose during this process. Labora­ into empty drums from an under­ no subsequent fuel drain check of tory analysis of samples of the ground installation leased by the the aircraft's fuel system. When water drained from the helicop­ operators at Kununurra aero­ questioned about this, the pilot ter's fuel system yielded results drome, there was no evidence of explained that " . . . we do not consistent with the theory that the any water testing having been car­ normally do water checks in the water had come from the irrigation ried out either before or after the field as the engine is not shut down canal. The volumetric capacity of decianting operation. Secondly, during refuelling." The fact that the hose was approximately a once the drums had been filled, refuelling with the engine running ... third of a pint per foot, •and it they were loaded upright on the is in itself entirely contrary to the would have been easy for the hose refuelling tender, where they re­ requirements of Air Navigation to have taken in sufficient water to mained overnight in the open. Order 20.9, paragraph 2.2.6, was produce the results found while evidently quite beside the point ! The only form of checking evi­ it was submerged in the 14-foot­ dently used during the actual re­ In addition to contravening this wide canal. fuelling of the helicopter was to and A.N.O. 20.2, Paragraph 20.2.5, Investig·ation of the refuelling run a few strokes of the hand relating to fuel system inspections, procedures used by the particular pump through the hose on to the the pilot and refuelling crew had operating crew revealed that they ground, after which the hose was chosen to ignore the requirements were, to say th e very least, highly inserted directly into the aircraft of the operator's Operations Man­ unsatisfactory. In the first place, tank and the delivery made. No ual, which lays down most strin­ although the fuel was decanted fuel filter was used, and there was gently the procedures to be

MARCH, I 9 6 6 9 followed in the handling of drum this wias a further contravention Whether the pilot's carelessness stocks and during· refuelling ope­ of A.N.O. 20.9, this time, paragraph was the result of his having been rations. 2.4.4. accustomed to more sophisticated Overshoot leads to Overturn refuelling methods overseas while The pilot of the helicopter, al­ Attempting to land at Tabibuga, a one-way airstrip in the New Guinea high­ A further unsatisfactory 1aspect though holding a valid Australian engaged on non-agricultural heli­ was the fact that during the re­ Commercial Pilot Licence endorsed copter operations, or whether it lands, a Cessna 185 carrying freight for the nearby Patrol Post overshot and touched fuelling operation the plastic gar­ for both fixed wing aircraft and sprang from mere ignorance of the down too fast. The pilot braked heavily, the aircraft skidded for some distance then den hose was the only connection helicopters, was not an Australian Department's requirements, is diffi­ tipped over on its back. The aircraft was badly damaged, but the pilot was not injured. between the fuel drum, the refuel­ citizen and had been t1,ained over­ cult to say. But whatever the rea­ seas. Although his total aeronau­ ling tender and the helicopter. The son, the pilot is no doubt infinitely Tabibuga airstrip, typical of blades began to slash the g-round, tion of Air Navigation Regulation tical experience amounted to over wiser now. Perhaps others, simi­ consequences of disregarding elec­ many in the highlands of New the n ose dug in and the aircraft 143 (1) (ba), which requires air­ 6000 hours, of which more than a liarly cavalier in their attitude to trical bonding requirements during Guinea, lies 4300 feet a:bove sea craft to join the traffic pattern third was helicopter time, he had refuelling procedures, can now somersaulted violently ·on to its refuelling are dealt with elsewhere flown over 280 hours on agricul­ learn the same lesson without writ­ level in mountainous country and back, sliding to a stop only 70 feet of a non-controlled aerodrome on in this issue. (See pages 14 and tural helicopter operations, most ing off a valuable aircraft in the is aligned north-east-south-west from the end of the strip. the up-wind, cross-wind or down­ 15.) It will suffice to say here that of it since coming to Australia. process! with an 8.7% slope up from the wind legs. The pilot had obviously The weather a\; the time was south-western end. Within 200 not given much thought to the fine, with unlimited visibility but yards of the northern side of the likely consequen ces of an abbre­ a seven-knot wind blowing from viated circuit procedure that al­ strip a heavily timbered ridge rises the south-west was producing a to 150 feet above the strip and on lowed him so little time to make pronounced down-wind compon­ the southern side and immediately a decision at an aerodrome where ent in t he landing direction. The beyond the north-eastern end, the decision, once made, is irre­ pilot had nearly 600 hours' aero- Cessna 185 destroyed after striking ·Fence ridges of similar height encroach vocable. In this case, the comple- almost to the strip's edge. For this reason, a pilot making an rupproach While taking off from an agri­ up weight at least equal to that Tests showed that a fully laden to Tabi1buga has to decide very cultural strip near Gladstone, New carried on the last load, and on Cessna 185 can leave the ground early on final whether or not to Zealand, a Cessna 185 failed to each occasion the aircraft became in 950 feet, and it was evident that continue, and once h aving decided become properly airborne and the comfortably airborne just hefore the aircraft was becoming airborne to do so, he is ·committed to a tail struck a post and wire fence, reaching the "hump." Wind c0ndi­ within this distance on the runs landing. tearing off the port elevator. The tions had been calm until fifteen before the accident. The strip was aircraft left the ground and flew minutes before the acci1ent, when therefore satisfactory for the The pilot of the Cessna, after flying from Mt. Hagen, had ap­ out over the slopes which fall away occasional gusts gave the first indi­ operation provided the aircraft proa'Ched the strip from the south­ steeply 'beyond the end of the strip, cation of a down-wind condition could become airborne before west. Close in, he made a right­ then dived into the ground several developing on the strip. Two hours reaching the "hump." Nevertheless, hand turn to place the aircraft hundred feet below. Examination after the accident a strong wind because in calm conditions the on a low-level base leg, lowered of the wreckage showed that as was blowing down the strip and it aircraft was not leaving the .gTound 20 deg. of flap and reduced speed well as removing the elevator, the was apparent that the last take-off until after running 950 feet, it was to 80 knots. He had turned on to a short final approach, closed the impact h ad also disrupted the tail­ had coincided with the onset of a clear that only a slight down-wind throttle and lowered full flap be­ plane trim jacks, allowing the tail­ continuous down-wind component component would have been n eces­ fore he realized that the aircraft plane enough free movement to de­ on the strip. sary to extend the run to more was over-shooting. Too low now to prive the pilot of all control. An aircraft failing to bec:ome than 1000 feet, i.e. to the point abandon his approach, the pilot airborne by the time it had run where the strip began to rise. thus had no alternative but to continue The total length of the strip was with the landing and he forced 1000 feet down the strip would then placing the aircraft in difficulties. 1318 feet, but surface undulations the aircraft on to the ground at nauti·cal experience, but had been have to run uphill for 120 feet and The accident shows that when tion of a proper circuit would reduced the useful length to about over 80 knots some 300 feet beyond flying for the operating company have enabled him to see that there would probably cease to accelerate strip operations in calm conditions the threshold. Holding the control 1000 feet. Initially, the strip runs for only 2¥2 months before the was a substantial down-wind com­ and perhaps even decelerate during column right iback he applied full down-hill for about 1000 feet, then leave only a small margin of safety, accident, an d of this time, six ponent on the strip and given him this time. Under such circumstan­ it is especially necessary to watch braking to try and stop the air­ weeks had been spent in route time to make adequate allowances for 120 feet rises abruptly into a craft before it ran into t he hillside ces the length of strip up the for the onset of any down-wind endorsement training under the fo r it. "hump" before curving downwards beyond the end of the strip. He supervision of the chief pilot. again over the final 200 fe':! t to "hump" would at best con i.1 ibute component which may make all the was able to hold the aircraft in a No doubt the wisdom of following the fence line. nothing to attaining flying speed difference between a successful flying· attitude at fi rst, but as the The approach technique that t.he the correct procedures is now and, on reaching the ere.st, the take-off and one ending in disas­ speed fell off, and elevator control pilot employed was in complete clearly evident to this pilot. There The aircraft had made at least pilot would be left with a down­ ter. was lost, the aircraft 1began to tip disregard of a company instruc­ may be others similarly inclined 48 take-offs from the strip that hill grade of only 200 feet in which forward on its nose. As it ap­ tion requiring pilots to complete to take 'short cuts,' who can profit Depar tment of Civil Aviation, proached the end of the strip, still full circuits at non-controlled aero­ from his frightening and expensive morning, many of them at an all- to become airborne. New Zealand travelling quite fast, the propeller dromes, and was also a contraven- experience.

10 AVIATION SAFETY DIGEST MARCH, 1 9 6 6 11 STALL tion, the Maintenance Release had would have been found and re­ the surface wind was blowing ~ .- • • expired and the flight was thus a placed, and the accident would not strongly at an angle to the line contravention of Air Navigation have happened. The importance of the sandhills and should have of properly maintaining engine Regulation 34 (1) (a). recognized that these conditions control linkages has been stressed were likely to produce a marked The general condition of the repeatedly in the Digest, and this wind gradient in the area between aircraft suggested that it was nor­ accident only serves to underline the ridges. By allowing for this mally well maintained, and it was these earlier warnings. condition and approaching at a evident that the reason for the The other aspect of the accident higher airspeed, the pilot would lapse of the Maintenance Release that bears thinking about is that have had a margin of safety to was only an oversight on the part the forced landing was being made cope with the steep wind gradient of the aircraft owner. Neverthe­ on to a reasonably good surface that evidently existed at around less, the fact remains that the and should have been successful. the height of the sandhills. engine failure resulted from in­ It was unsuccessful, and the air­ Such conditions should never be adequate maintenance, and if the craft was written off because the a reason for losing control. On 100 hourly maintenance inspection pilot failed to monitor the air­ the contrary, they should only act had been carried out at the proper speed during the final stages of as a stimulus to watch an approach time, the defective ball joint his approach. The pilot knew that even more intently.

Some Radio Incidents PA22 atmospheric conditions were such SURFACE VEHICLES When making a charter flight that this was impossible. In At Sydney airport, the surface from Kairoo to Clovernook, thunderstorm conditions an ade­ movement control frequency be­ Queensland, a P A.22 failed to quate listening watch can only be came jammed by a continuously answer calls from Rockhampton maintained by the use of ear­ operating transmitter. A large communications unit. At 0544 the phones. number of departing and arriving aircraft had reported estimating F27 aircraft were affected, and it be­ Clovernook at 0615 and a minute Over Holbrook, while en route came necessary to handle all air­ Soon after departing from a Western Australian cattle station for Carnarvon, later Rockhampton called the air­ from Melbourne to Canberra, the craft movements on the approach Western Australia, a Chipmunk sustained a complete loss of engine power. During the en­ craft to pass traffic information. crew of an F.27 experienced a control frequency. Meanwhile, all suing forced landing approach, t he pilot lost control and. the aircraft nosedived il\•io t.he No reply was received. Adjacent complete failure of the aircraft's company and departmental ground. The Chipmunk was virt ually destroyed but the pilot and passenge r escaped with COM stati'Ons and other aircraft vehicles were checked for sources a shaking. communication equipment. All in the area were then asked to frequencies were tried in an at­ of interference and the continuous call the aircraft, but without suc­ tempt to contact air traffic control, carrier transmission was finally cess. The uncertainty phase was The aircraft was 1being flown by proach. The surface wind was but to no avail. The flight was traced to a Department of Works knifed behind the rear cockpit. declared at 0600, but, when the a private pilot and it had taken blowing at about 30 knots from Fortunately for the pilot and pas­ continued to Canberra, and a let­ vehicle which was being used in aircraft called and reported circuit off for the 75-mile flight to Car­ the south-west, at an oblique angle senger, the cockpit section re­ down was carried out in accord­ the reconstruction of a taxiway. area Clovernook at 0620 this was narvon at 11.40 local time. Shortly to the line of the sandhills, and mained reasonably intact. ance with the radio failure pro­ Technicians found that the glove cancelled. Communication condi­ after the pilot had levelled out at he elected to land slightly out of Investigation of the wreckage cedures. It was later found that box lid of the vehicle had fallen his selected cruising altitude of wind to obtain a landing run tions throughout the flight were the aircraft transmitters were open and was pressing down on showed that the throttle linkage poor. The pilot said later that 3500 feet, the engine R.P.M. parallel to the sandhills. had failed when the throttle con­ permanently keyed, thus prevent­ the press-to-talk button on the dropped to idling without warn­ after transmitting his iposition re­ ing reception. The fault was microphone. The microphone The pilot maintained a steady trol rod connecting the carburet­ port at 0544, he had removed his ing. The pilot went through the 60-knot glide then , on final, tor to the cross shaft beh in d the traced to a selector 'box on the holder in the vehicle was so emergency cockpit drill and fo und earphones and had maintained a control pedestal and the unit was located that this would occur brought the speed back to 55 knots. en gine became disconnected. The listening watch on the cabin that movemen t of the throttle lever About 30 feet above the ground, failure no doubt resulted from wear removed for overhaul. During the whenever the glove box was opened had no effect on the engine. speaker. On arrival over Clover­ overhaul, a sticky substance, to­ to its full extent. The fault was just as he was about to round out, in the ball joint and consequent nook he had again used the ear­ The pilot transmitted a Mayday he saw that the airspeed indicator looseness of the fittings. The Main­ gether with evidence of moisture, also attributable to a faulty cradle phones. He admitted he had been was found in and around the switch on the microphone. In call and position report then looked had dropped to stalling speed. Al­ tenance Release for the aircraft, having some difficulty during the around for the most likely area most at the same instant, the which was registered in the private selector box COM switch. It was normal circumstances the equip­ flight in reading stations on HF apparen t that at some time a cup ment cannot be activated while for a forced landing. He selected aircraft stalled, the nose dropped category, had ·been issued fourteen because of storms in the area. a fla t piece of ground covered with and the aircraft struck the ground mon ths previously, and was valid of tea or coffee had been spilt the microphone is lying on its ligh t scrub, lying ·between two heavily, about 45 degrees nose­ for 100 hours' flying or twelve The cause of this incident was over the selector box and in the cradle. The incident nevertheless parallel sand ridges about fifty down. It bounced twenty feet and months, which ever occurred first. that the pilot endeavoured to course of time the resulting sticki­ demonstrates that radio equipment feet high, carried out his forced came to rest with both wings Although the aircraft had flown maintain a listening watch on HF ness ha d caused the malfunction should be kept clear of obstruc­ landing check and set up an ap- broken off and the fuselage jack- only 79 hours since the last inspec- with the cabin speaker when in the switch. tions at all times. MARCH, 1 9 6 6 12 AVIATION SAFET Y DIGEST 13 The pilot of the Debonair shown in the photographs below ohviously didn't remember! Short of Do you remember • • fuel, the aircraft had previously made a precautionary landing, on a roadway in a remote part of Western Australia, and had sustained minor damage. Aircraft engineers went to the site and repaired it for a ferry fiight to Port Hedland and when it was ready, a pilot arrived to fly it out. He had brought with him two four-gallon drums of avgas, and set about refuelling the aircraft. First of all he earthed the aircraft by forcing a long screwdriver into the ground and connecting it to an earthing lug on the air­ craft. Using· a plastic funnel, over which he had placed a dry chamois, he tried to pour the' contents of one drum into the starboard tank, but found he could not hold the funnel and pour the fuel at the same t ime. After he had spilt a small amount of fuel he asked one of the engineers to help him. The engineer took the drum while the pilot held the cham..,1s and funm~I. More fuel was spilt when the engineer t ried to pour with the neck of the drum downwards. The engineer then turned the drum round so the neck was uppermost and began pouring again, but after about half a gallon had flowed into the tank, l fire broke out at the filler neck and spread quickly. The engineer sufft;red minor burns to his hands before he could jump clear and the fire engulfed the aircraft. The aircraft was fitted with two fire extinguishers, J but because these had been left in the cabin, they could not be reached once the fire had broken out. In any case, small nand extinguishers would hardly be adequate to deal with a refuelling fire once it had . don't give Before ... est ablished itself. 5TATI£ I £tf£ff{11:rfY a CHANCE\

---After! , There is no doubt that the fire was started by a static discharge. The static electricity hazard In the JUNE~ 1965 DIGEST • involved in using a plastic funnel that cannot effectively be earthed is serious enough at any time, but .1 it would have been compounded on this occasion by the extreme heat of the day. The shade temperature We commented .. . at the site was + 40°c. and as the aircraft had been standing in the sun, the surface of the wing would " . . . t he Department and some oil companies as well, have warned against the use of plast ic have been very hot indeed. The spilt fuel would have quickly formed dangerous vapour that only required containers and funnels for refuelling ... ) the slightest spark to ignite it. The likelihood of a static discharge in these circumstances could have been eliminated by ensuring that t he aircraft, the drum and the funnel were all at the same electrical poten­ " ... plastic articles can accumulate a heavy static charge. Because the plastic will not con.duct tial. This is normally achieved by electrically bonding the three elements, but such bonding can never be electricity, th e charge cannot be eart hed properly b y earthing cables and clips. A statically charged effective while one link in the chain, the funnel, is non-conductive plastic. plastic utensil can therefore quite easily cause a spark when placed close to metal fittings such as fuel tank filler neck or a refuelling haze nozzle. "We have noticed that some light aircraft pilots who conduct their own refuelling operations in Remember: country areas, still occasionally resort to the use of plastic funnels or containers for the sake of expe­ diency. If you are one of these, we urge you in your own interest to discontinue the practice immediately." REFUELLING + PLASTICS STATIC DISCHARGE

14 AV I ATION SAFETY DIGES T MARC H, 1 9 6 6 15 It might be argued that the cases we have de­ feeling across his forehead. As time went on he had CABIN HEATERS and CARBON MONOXIDE scribed are isolated ones and that they haven't a difficulty in focusing his eyes, his sense of balance great deal of application to the vast majority of deteriorated, he became incapable of working out normal light aircraft operations, but they do serve even simple navigational problems, and he felt a From time to time, the Digest has quoted various carbon monoxide contamination checks as a routine to illustrate how easily and unsuspectingly carbon compelling urge to fly closer an d closer to the ground. overseas reports of fatal accidents to aircraft caused part of the type-certification for new types of air­ monoxide contamination can occur in an aircraft. The pilot was wise enough to realize something was by incapacitation of the pilot or crew as the result craft, but even with these safeguards, there have This brings us to an item of equipment fi tted to seriously wrong and he landed the aircraft at a of carbon monoxide leakage from a faulty cabin been cases where new aircraft have later proved most modern light aircraft which, although fully strip which was a few miles closer than his destina­ faulty in this respect. In most of these instances, the tion . Here he walked around for half an hour until heater. Now that the summer is over and many pilots meeting the design specifications we have already type-certifications had been carried out on a proto­ mentioned, is an ever-presen t source of treachery he felt better, then flew on to Bourke aerodrome will be resorting to the use of their cabin heaters to type aircraft, and subsequent product.ion models and danger if it is not carefully maintained - the where he immediately declared the aircraft unser · make flights more comfortable in cool weather, it later underwent minor modifications which adversely aircraft cabin heater r,nd the engine exhaust system viceable. The aircraft's exhaust system was examined would be well to heed the lessons of some of these affected their cabin sealing or ventilation. A typical associated with it . and a 5/32 inch hole was fo un d in the heat ex­ overseas accidents to make sure none of them are case involved a single-engined cabin aeroplane in Most light aircraft cabin heaters utilize a heat chan ger. The hole had been made by an excessively repeated here. which a small hole had been cut in t he floor for a exchanger which consists essentially of a sheet metal long PK type attachin g screw, which had pierced the camera installation. The hole did not affect the jacket wrapped around part of the engine exhaust inner wall of the h eat exchanger. Carbon monoxide, a gaseous product formed by pipe or exhaust muffler . Ram air is admitted to the The best protection against carbon monoxide incomplete combustion of carbonaceous matter, is jacket usually through a flexible hose leading from poisoning is to be alert, as this pilot was, to its found in the smoke, fumes, or exhaust gases from an ai{· intake at the front of the engine nacelle, early symptoms - the smell of engine exh aust gases, stoves, furnaces, internal combustion engines, and heated in the jacket by the en gine exhaust, and a generally sluggish feeling, drowsiness, tightness across the forehead, h eadaches. If you experience almost any other process in which hydro-carbon fuels then ducted to outlets at various points inside the these warning signs, assume that carbon monoxide are used for power or heat production. The amount cabin. It is obvious that if a crack or a hole develops between the exhaust pipe and heater jacket, the is getting into the cabin and take all reasonable pre­ of carbon monoxide in the exhaust gases of a piston ram air will become contaminated and carbon mon­ cautions. Shut off the cabin h eater immediately and type aircraft engine varies with the ·operating condi­ oxide will be piped to the cabin hot air outlets. open a cabin window or other fresh air source. Re­ tions, but is generally proportional to the fuel/air Clearly, the danger will be greatest during the frain from smoking because this also increases the ratio of the mixture being fed to the engine. A full winter months when cold weather encourages full carbon monoxide level in the body, and make a land­ rich mixture setting for take-off power produces use of the cabin heater and the other cabin air ing at the first suitable areodrome. Do not resume about eight per cent of carbon monoxide by weight sources are kept closed, but it is as well to remem­ flight until all effects of the carbon monoxide have in the exhaust gases; a typical cruising power mix­ ber that carbon monoxide can also enter the cabin disappeared. At the first opportunity have the air­ ture setting will yield about three per cent. Because at any time through the various small openings craft checked for carbon monoxide contamination it is colourless, odourless and tasteless, the presence in the firewall, if gas leaks develop in other parts either by a thorough physical inspection of the sus­ of carbon monoxide is not readily detectable when of the engine exhaust system. Cracks and holes can pected components, or by having the cabin air mixed with air, and it is this factor that poses develop in a r elatively short time and, for this sample-tested under operational conditions. such a hazard when the gas contaminates the air The testing instrument, which the Department inside an aircraft cabin. uses for this purpose, is illustrated on these pages. The main feature is the replaceable glass indicator The toxicity of carbon monoxide to human beings Testi ng instrum ent and spare indicator tubes. tube containing yellow silica gel crystals. To use the is well known. A concentration of only 0.06 per cent. tester, the sealed ends of the indicator tube are in air inhaled can cause unconsciousness within two structural integrity or performance of the aircraft but broken off and the tube is inserted in a spring-loaded hours; 0.1 per cent. can cause death in as short a it provided a means by which cabin air could become holder on the instrument. An air sample is then time as an hour, depending on the physical condition seriously contaminated with catbon monoxide from drawn through the t ube by squeezing the rubber of the person affected. Even a concentration of car­ the engine exhaust. In another single-engined air­ bulb and allowing it to re-inflate. If the air thus bon monoxide as small as 0.02 per cent. can have craft, exhaust fumes were able to enter an area of sampled contains carbon monoxide, the yellow silica perceptible effects over a period of an hour and a reduced pressure in the fuselage, through an unsealed gel turns green, the depth of colour being directly half. The effect on pilots is particularly dangerous tail wheel strut aperture, again resulting in serious proportional to the concentration of carbon monoxide because it is so insidious - a pilot may suffer from carbon monoxide contamination in the cabin. In this in the air. To measure this concentration, the dis­ impaired vision and judgment, reduced alertness and case the source of the cabin contamination was dis­ colouration of the chemical is compared with a colour reasoning power, yet he may be completely unaware covered only after prolonged investigation. In yet sc:ale on a small cylinder mounted beside the tube, that his efficiency is deteriorating and so the gradual another case, a "do-it-yourself" modification to the the cylinder being revolved to bring the varying carbon monoxide poisoning process goes on un­ louvres of an engine cowling caused contamination shades on the scale successively into position fo r detected until it is too late - too late because the of the air flowing around the cabin cold air vent in comparison with the indicator t ube. The tester is pilot has already become unconscious, or too late the side of the fuselage, and allowed carbon monoxide capable of indicating concen trations of carbon mon­ because he had been reduced to a state in which he to be drawn into the cabin when the cold air vent rnstrument assembled ready for use. oxide from 0.001 to 0.10 per cent. is simply incapable ·of handling the situation that was opened. reason, exhaust man ifold an d cabin heater assem­ Should you have any reason to suspect carbon now confronts him. As a result of these and slmilar incidents, t he blies should be thoroughly inspected for defects, monoxide con tamination in your aircraft do not In the early days of enclosed cockpit aircraft, Department now requires carbon r.10noxide contami­ including blown gaskets, at regular in tervals. Some hesitate to ask the Department to arrange an opera­ there were a number of accidents caused by pilots nation checks to be carried out not only on new aircraft manufacturers in fact recommend inspec­ tional check wit h the test instrument; in certain becoming affected by carbon monoxide, and this led aircraft types during type-certification, but also on tions as often as every 25 hours flying time. cases t he Department will make the tester available to the adoption of design specifications aimed at any aircraft that has been modified in· a way that Not lon g ago, a private pilot flying a Cessn a 172 on loan fo r pilots to carry out their own checks. And keeping cockpit air contamination within safe limits. could possibly produce results similar to those from Cobar to Bourke, New South Wales, found him­ make it a habit to have your cabin heater inspected Today in Australia, the Department also carries out described. self suffering from inexplicable nausea, and a t ight i·egularly. Time so spent is time well spent.·

AVIATION SAFETY DIGEST 16 MARCH, I 9 6 6 17 Fatal Fire 1n• Wheel Brakes

(Based on Report by Commission of Enquiry convened by Federal Accidents Investigation Office, Geneva).

In September, 19G3, a Caravelle 3 engaged on a scheduled flight from Zurich to Rome via Geneva crashed eight minutes after take-off from Zurich. The 74 passengers and six crew were killed and the aircraft was destroyed.

After a lengthy and detailed in­ were, at that time, preparing for were found over the last seven vestigation, the Commission of En­ take-off, approval for which was miles of the flight path. quiry ascribed the crash to the given at 0712 hours. After a long and detailed investi­ destruction of important structural About one minute after take-off, gation of all of the factors which components by 'fire which was initi­ the ftight reported on top of the fog could have caused or contributed to ated ,by general heating of the bank at about 1700 feet and normal the accident, the investigating brakes before take-off. departure communications were authorities found that three inter­ effected. At 0721 the flight trans­ related facts could be used as a The Zurich airport was en­ mitted a MAYDAY call, after which starting point from which to recon­ L eft: Brake disc recov.ered from No. 4 wheel assembly showing deep grooves apparently made by heavy braking while shrouded in fog when the crew communication was lost. A ground struct the sequence of ever.ts. These taxi-ing on runway before take-of!. went aboard the Caravelle for de­ witness who saw the aircraft at were the fracture of No. 4 wheel be­ Right: A typical blow-out stain similar to the one found at the beginning of the runway from which the Caravelle took of!. parture at 0700 hours local time. At about this time noticed a whitish fore take-off, the qutbreak of fire 0705, after being informed that the stream of <;moke issuing from the while climbing, and the final dive burning on the wheels when the formance, which was followed by a braking, irrespective of the visibility on runways 16 and 34 was port side and then saw ftames to destruction. undercarriage was retracted, it deviation to the left and loss of circumstances which lead to such 60 metres and 210 metres respec­ stream out along the fuselage. The It was evident that the rim of could be expected to spread to the height. In the second phase, struc­ broking. In one recent local in -. tively, the crew asked for a guide aircraft continued straight on for No. 4 wheel broke away and the other wheels and eventually burst tural parts of the aircraft began to cident, fire broke out in the port vehicle and approval "to taxi on some time without sinking, then tyre burst while the aircraft was out of the undercarriage housing. fail and evidently control of the wheels of a Viscount ofter heavy the runway, on 34, and back again, turned left and began to lose turning on to the take-off heading Alternatively, there was evidence to aircraft became increasingly diffi­ braking. In this case, the air­ and have a look round." This re­ height. Finally, it went into a steep at the beginning of the runway. show that there had also been a cult. The final phase, in which the craft was taking off on o quest was approved and a guide dive and disappeared from sight The state of the brake mechanism primary fire in No. 3 wheel (the aircraft entered the vertical dive, scheduled flight and one engine vehicle was provided. into the fog crashing into open led to a reliable conclusion that the rear outer wheel on the port bogie, was probably produced by loss of was observed to be below nomi­ fields about 19 nautical miles from braking system had been over­ adjacent to No. 4) and its brake rigidity in the port wing structure, nal power. Take-off was rejected After guiding the aircraft out the airport at 0722. It was sub­ heated and experiments and tests discs showed clear signs of over­ loss of hydraulic power for the con­ just below V1 and the aircraft from the apron, the vehicle driver sequently cstablshed, from the carried out proved that such over­ heating. Tests and calculations trol system and structural damage was braked to a halt. The air­ lost his way in the dense fog, to the data recorder, that the aircraft had heating could lead to a wheel frac­ established that wheel rims do not to the port tailplane. craft was taxied back to the extent that he entered "taxiway 4" reached 8780 feet before it com­ ture of the type that occurred to reach their maximum temperature terminal, the other three engines instead of "taxiway 5" and guided menced to lose height. the No. 4 wheel. for a few minutes AFTER the COMMENT were cut and g round running the aircraft on to runway 34 at a Fragments of the outer rim of The external picture of the original braking process, hence it In their investigat ion of this commenced on the suspect en­ point about 400 metres from the No. 4 wheel (the rear inner wheel events, obtained from eye witnesses, could well have been that No. 3 accident the authorities respon­ gine. In the course of this threshold. The aircraft turned on on the port nndercarriage bogi.e), is one of a rapid change, a few wheel rim also burst after take-off, sible went to great lengths to ground running, fire broke out to the runway and proceeded in the an earthing cable with its attach­ minutes after take-off, from a trail causing damage to fuel lines and determine the cause of the in the port wheels. Several other take··Oft' direction for some 1400 ment, a blow-out stain, a small of white smoke coming from the the ignition of a separate :fire which brakes overheating, with par­ coses of a simi lar nature have metres, then turned and taxied quantity of hydraulic oil and traces aircraft to a sudden and extensive eventually ate its way out of the ticular reference to the possibility occurred during training. back to the threshold. Witnesses of burnt oil were found at the be­ fire in the vicinity of the retracted undercarriage housing. In either that high engine powers were working in the vicinity of the run­ ginning -0f runway 34. The blow­ port undercarriage while the air­ case, it can be deduced that the used as a means of improving One significant fact empha­ way later testified that while the out stain was between the tracks of craft was climbing. In considering fire was caused by overheating of runway visibility whil e the air­ sised in the report on the acci­ aircraft was taxi-ing on the run­ the two pairs of wheels of the port the circumstances which led to this the brakes. craft was taxi- ing on the run­ dent is that the temperature in way, the engine noise level was main undercarriage and, beyond sudden outbreak of fire, the investi­ In their reconstruction of the way. Several hypotheses were the wheel rims continues to rise considerably louder than that this point, ~ he wheel tracks were gating authorities were faced with various phases of the ftight, the explored but no firm conclusion for several minutes after braking normally associated with taxi-ing. covered with hydraulic oil. Parts two alternative hypotheses. Firstly, investigating authorities concluded could be reached on the evidence has ceased. This fact should be of the tyre of No. 4 wheel were it was known that hydraulic oil that the ftight proceeded normally available. Although isolation of kept in mind when assessing the At 0709 the crew reported that found along the take-off tracks escaped from the brake system im­ for about ·five minutes, with the the specific cause of overheating time interval that should be the fog was in banks, with varying over a range of 1350 to 1700 metres mediately following the blow-out of crew unaware 1Jf the situation that was important in relation to this al lowed between an abandoned conditions ~nd that the blast of from the beginning of the runway. No. 4 tyre, and that this oil was was developing. Information de­ particular accident, the long take-off and the beginning of their exhaust had had some effect Other parts of the aircraft, from burning at the take-off end of the rived from the data recorder indi­ term significance of the accident another run, particularly when in clearing the fog from the run­ the port undercarriage area, the runway. If the fire started when cates that the first obvious effects is its demonstration of the dan­ the aircraft wheels ore not fitted way. They intimated that they port wing and the rear fuselage, No. 4 wheel blew out and was still were a falling off in aircraft per- ger that con exist after heavy with fusible plugs.

18 AVIATION SAFETY DIGEST MARCH, 1 9 6 6 19 is sometimes called, results from a process quite dif­ ferent from that by which structural ice is formed on aircraft, and it can form in conditions in no way conducive to the formation of structural ice. Indeed, if the humidity of the free air is high enough, car­ burettor icing can occur in air temperatures as high as 27°C. The ice may form in various places and on various parts of the induction system- in the air intake, in curves of the inlet manifold, at the main jet, in the venturi, or on the throttle butterfly valve. Ice formation in the induction system causes a loss of engine power by obstructing the air passages and disturbing the fuel metering, and in extreme cases, by rendering movable parts inoperative. Three types of icing can occur in aircraft engine induction systems: refrigeration icing, throttle icing and impact icing. REFRIGERATION OR FUEL - EV APO RATION ICING is caused by evaporative cooling of all induc­ tion system surfaces that are wet with fuel. This type of icing occurs ·on days when the humidity of the air is high, with moderate air temperatures be­ tween 5° and 27 °C. If the surfaces are cooled below the local dew point or if free water is present and Carbur ettor i cing forced this Aust er down only a few the local temperature is reduced below 0°C, then ice minutes after taking of]. T he aircraft struck a fence forms and builds up on the surfaces. Float-type during the landing. carburettors, which mix fuel with the air before it is likely to be troublesome when engines are running reaches the throttle so that the fuel is evaporated with the throttle nearly closed, for example when during the throttling process, are especially liable to warming· up on the ground, but generally it clears this form of icing, which is the result of the re­ frigeration action that accompanies the vaporisation when the throttle is opened. The additional cooling of the fuel as it combines with the air. The effect in the throttle does, however, intensify ot her "Carburettor Icing: A sweet substance applied engine was subsequently checked and found fault­ principle can be demonstrated easily by placing a icing effects. over carburettors to improve palatability and/or less. small amount of avgas on your hand, and noting the IMPACT ICING: The conditions required for appearance." Thus was the condition defined in a At Geraldton, Western Australia, the engine of a cooling effect as the fuel evaporates. Because the the formation of impact icing in t he induction sys­ little piece of light-hearted nonsense entitled "Avia­ Cessna 175 failed to respond when the throttle was heat required to evaporate the fuel is taken from tem are similar to those that produce airframe icing. tion Terms," that appeared recently in one of our opened after a simulated forced landing approach, your hand, you experience a cooling sensation. For this reason it is not as insidious as the other overseas contemporaries ! But if last winter's spate and the aircraft had to be force-landed in the field The interaction of the various factors involved, two forms of carburettor icing. Impact icing occurs of carburettor icing reports is any indication, some already selected. This time the forced-landing was such as the volatility of the fuel, manifold pressure, when the air temperature is between minus 10 and pilots' comprehension of the problem isn't much successful. The engine continued to idle after the air­ air temperature and humidity, is complex. However, 0° c, and supercooled water droplets strike any part closer to reality ! craft had been brought to a stop, but opening the the practical result with normal aircraft fuel is that of the air intake or induction system. In these con­ The Auster Autocar shown in the picture on the throttle produced almost no response. Carburettor serious evaporative icing will not form with air ditions, the water droplets, at a temperature below next page was the victi:rr. of this inexpertise. Loss of heat was selected on and the engine left running. temperatures above 25°C whatever the humidity, or freezing but still in liquid form, freeze immediately engine power from carburettor icing forced it down After a short time the carburettor ice cleared and with a relative humidity below 60 per cent, whatever they come in contact with any surface colder than only a few minutes after taking off on a cross coun­ the engine was capable of being run-up normally. the temperature. The most severe icing occurs when 0°c. Supercooled moist ure may be encountered in try flight in South Australia, because the pilot didn't The aircraft was then flown back to Geraldton the outside air temperature is around 13°C. Obvi­ the form of freezing rain, clouds or wet snow. Above recognize the trouble in time to correct it. Aerodrome, where an inspection failed to reveal any ously, the icing will be more severe if there is water minus l0°C, clouds always contain water droplets Not long afterwards, in New South Wales, an defect in the engine. Weather conditions at the time in liquid form in the outside air, so pilots should be and so are prolific sources of impact icing, wh ich almost certain accident in similar circumstances was were conducive to the formation of carburettor ice, particularly alert for icing during flight in rain or can build up on air intakes, heater shutters, duct averted only by the watchfulness of a Sydney com­ with a series of cold fronts accompanied by heavy cloud at these temperatures. For a given relative walls, carburettor screens, t hrottle butterflies and munications officer. A private pilot flying a PA.22 showers passing through the area, and there was six humidity, the severity of this type of icing decreases carburettor metering elements. The most serious from Goulburn to Bankstown reported to Sydney that eighths of strata-cumulus and cumulus cloud at with a reduction in temperature and it is unlikely to form of impact icing is clear ice which occurs readily his engine was running roughly and that he might 3000 feet. give trouble at temperatures below minus 10°c. at around minus 5°C, especially at high airspeeds, have to force-land. The alert phase was declared These three cases are sufficient to show how THROTTLE ICING: A reduction of air pressure when t here is a high liquid water con tent in the and close contact maintained with the aircraft. The vitally important it is for pilots to be able to recog­ air, or when the water droplets are large. engine continued to lose power and the pilot next nize the conditions in which the carburettor heat and a consequent fall in air temperature, accom­ reported he was down to 300 feet above rough terrain control should be used. This can be achieved by panies the increase in the velocity of the air as It can now be seen that carburet tor icing is not and was losing height at 200 feet per minute. Asked learning to recognize t he atmospheric conditions it flows through the carburettor venturi and past t he only a low temperature phenomenon, but that it can by Sydney if he was using carburettor heat, the favourable to carburettor icing and by being alert throttle butterfly. When free water from rain or occur at air temperatures well above freezing· point, pilot selected it on and almost immediately the en­ in such conditions for symptoms of icing in aircraft cloud is present, ice is likely to build up on the and in clear air as well as in cloud and precipitation. gine cleared itself and ran normally again. The pilot engines. surface cooled by the air stream, even at outside air Moreover, t he onset of carburettor icing is not always continued to an airstrip near Mittagong where the Carburettor icing, or induction system icing as it temperatures up to about 5°C. This form of icing apparent and its symptoms can easily be confused

20 AVIATION SAFETY DIGEST M ARCH, 1 9 6 6 21 1! with other engine troubles. Unfortunately, no com­ is good practice to use carburettor heat at frequent pletely reliable icing indicator has yet been devised, intervals, to check for the presence of ice in the but the only remedy is nevertheless prompt and cor­ induction system. This can be done most effectively rect use of carburettor heat. One of the best indica­ by noting the manifold pressure (or r.p.m., in the tions of icing in the induction system is an other­ case of a fixed pitch propeller) with the control in YOLIR NEW wise unaccountable loss of manifold pressure (or the cold position, applying full heat to melt any r.p.m., with a fixed pitch propellor) which is restored ice present, then returning the control to cold. If after carburettor heat has been applied for long the power indication is higher than previously when enough to melt away any ice present. Remember the control is returned to the cold position, ice had that a small loss of power will always occur when formed. When using carburettor heat in this way, carburettor heat is selected on, whether or not ice be sure it is applied for long enough to get rid of has formed. But if ice is present, the power will an the ice which might have formed in the induc­ steadily increase again, though of course not quite tion system. Even hot air cannot do it instan­ to the original setting until the carburettor heat taneously - remember how long it takes to defrost control is returned to "cold." a refrigerator. In most cases about thirty seconds Icing in the induction system has exactly the should be sufficient. same effect as gradually closing the throttle. The Carburettor icing can also occur on the ground air fl.ow through the carburettor is progressively re­ during taxi-ing or while the engine is idling. Last stricted as the ice deposits build up, reducing the winter in fact, there were at least two instances of power being developed by the engine. Often, when engines stopping while aircraft were at the runway pilots fail to recognize the symptoms of carburettor holding point and the cause in each case was attri­ icing, they go on opening the throttle little by little buted to carburettor icing. Most light aircraft to compensate for the gradually falling manifold operators stipulate that the carburettor heat control pressure or RPM indication. It is just this set of should be left in the cold position during ground circumstances that can lead to a complete loss of running to obtain the benefit of the air intake filter. power, for if the application of carburettor heat is This of course, is entirely reasonable, but it is delayed too long, the ice accumulated in the induc­ Important that the operation of the carburettor heat Within the next few weeks, a new D .C. A . publication, the "Visual Flight Guide", tion system may be too much for the carburettor control should be checked during run-up, not only should be e.vailable for distribution to all holders of the present Light Aircraft Handbook. heat available at the resulting reduced engine to see that it is working properly, but also to ensure The Visual Flight Guide is intended to replace the Light Aircraft Handbook. General avia­ power. that any carburettor ice formed during ground run­ tion pilots will recall that this move was foreshadowed in Aeronautical Information Circular If icing conditions are suspected during flight, it ning is cleared before take-off. 10/ 1966 i ilsu.ed in January this year.

More truly a "handbook" than its predecessor, cause the size of the Visual Flight Guide will be too the Visual Flight Guide is a bound octavo sized book, small to contain the plastic pockets previously issued covering somewhat more comprehensively, the whole for the V.E.C.s, a special plastic map holder is to be Oxygen Equipment Explosion range of aircraft operational procedures. The book made available for this purpose. is, in fact, a synthesis of the Light Aircraft Hand­ In addition to the normal distribution to private book, the Aeronautical Information Publications, pilots and to those commercial pilots who normally The article, "Fire dangers in oxygen systems" The fire was carried down-stream into the flexible suggestions from the aviation industry, and recom­ use the Light Aircraft Handbook, a number of copies in our March, 1965, issue (see Aviation Safety Digest hose, which burst under pressure after being weak­ mendations of the committee appointed by the of the Visual Flight Guide will be issued to every No. 41) referred to an overseas incident in which a ened by heat. Examination of a second valve in the Director-General to look into the needs of general flying school and aero club for distribution to student fire broke out in the cockpit of an aircraft while an recharging equipment showed that it too had shed aviation in Australia. The information it contains is pilots who have reached a certain stage of their oxygen •bottle was being replaced. The article empha­ chips of the gland material. presented more systematically than previously and in training. In this way, the Department intends that sized the risks that are involved in handling oxygen a more easily readable form. the Visual Flight Guide should be readily available equipment, particularly the danger of spontaneous This accident is a classic example of the dangers It will not be necessary to amend large sections to all who have a genuine requirement for it. ignition as a result of adiabatic compression when a associated with handling high pressure oxygen. As of the Visual Flight Guide every two months or so. Altogether, we believe that the introduction of shut-off valve is opened too suddenly. An accident pointed out in our earlier article, if substances having Instead, the Department intends to reprint the book the Visual Flight Guide represents a significant step of this type actually occurred in an airline company's a low ignition temperature are present in any oxygen approximately every 12 months, or whenever large forward in simplifying flight planning and actual oxygen cylinder recharging plant at Adelaide Airport system, the rise in temperature which takes place or significant changes demand it. It may not even operational procedures for the majority of general recently, causing a flexible hose to explode and inflict spontaneously when the pressure is suddenly in­ be necessary to reproduce the Flight Guide every 12 aviation pilots, particularly those in the private cate­ injuries to an L:A.M.E. who was operating the creased can cause them to burst into flame. For months as the greatest single source of amendments, gory. By comparison with the Light Aircraft Hand­ equipment. this reason, an oxygen cylinder valve should never the information previously contained in the MAP book, the Visual Flight Guide is handier in size, An investigation into the cause of the accident be opened suddenly. By opening it very slightly at. section of the Light Aircraft Handbook, will now, for easier to carry and stow in a small aeroplane, the esta:blished that the trouble apparently originated in first, the oxygen can be •bled slowly into the system, the most part, be printed on the back of the Visual sequence of topics follows a more logical operational one of the shut-off valves of the recharging equip­ thus allowing the pressure to build up gradually Enroute Charts (V.E.C.s). Information on the back order, and a comprehensive index enables the reader ment. Continued operation of the valve had resulted without a rapid increase in temperature. Absolute of the V.E.C.s will include Visual Terminal charts, to find the information he is seeking very quickly. in small pieces of material chipping off the plastic cleanliness is, of course, vital in handling oxygen details of air traffic control, communication and We like to think that the advantages of this new valve gland and the valve seat. It is believed that system components, but even when the utmost care radio navigation services, and prohibited, restricted method of presentation will, in time, be reflected in the fire started when the chips of the gland and is taken during assembly, it is impossible to be certain and danger areas. It will thus be possible to deal an overall improvement in airmanship and flight valve seat material ignited as oxygen at 2,200 lb. that valves and pipe-lines will always remain free with most amendments to operational information, procedures throughout the general aviation indus­ per square inch was suddenly admitted to the valve. from combustible particles. merely by re-printing and re-issuing the V.E.C.s. Be- try !

22 AVIATION SAFETY DIGEST MARCH, 1 9 6 6 23 Comet Strikes Ground During Approach Lost And Found

(Summary of Report Issued by Ministry of Av iation U.K.) Just one year ago in an article entitled "Air Age Jetsam" we discussed the problems being posed by tools and other maintenance equipmen t left in aircraft engine bays and wheel wells. The article instanced two cases of damage caused to aircraft With the first officer flying the meter to 938 instead of 839 mbs. 2,000 feet. His cockpit roof light and two in which pieces of equipment fell into closely The aircraft then made a normal was full on at this time and he did aircraft from the right hand seat, settled residential suburbs from aircraft in flight. a Comet 4 commenced descent for landing and taxied to the apron not look out of the aircraft. a straight-in night approach to unaided. Damage was confined to The accident resulted directly Since that time, far from diminishing, the prob­ two cut tyres, a fractured brake lem has continued to mount alarmingly. The extent Nairobi, Kenya, 5,327 feet above from the fact that the first officer line, and a damaged tie rod on to which it has grown is best shown by the follow­ mean sea level. The terminal wea­ unconsciously transposed the fig­ the starboard main undercarriage. ures of the QFE in setting his alti­ ing list of some of the tools and aircraft parts found ther was fine with 2/8ths of clouci by airport maintenance staff on runways and taxi­ The premature touch-down had meter. Errors of transposition are iat 2,000 feet, QNH 1020 and QFE easily made and 1are often not im­ ways at major airports at various times during past 839. At 20 nautical miles DME, the occurred on a patch of open coun­ months:- try dotted with outcrops of vol­ mediately apparent to the person first officer called for the approach canic rock some 9 miles from the making them. Because such errors Adelaide: Pair of multigrips are difficult, if not impossible, to check and began to wind the star­ runway and the extended under­ Brisbane: Jacking pad, cold chisel board altimeter back to the QFE carriage had left impact marks 195 prevent, cockpit drills and checks have been developed to ensure that Broken Hill: Hose clamp setting Qf 839 mbs. In doing so, he yards long and up to 5 inches deep. if errors are made, they will be Cairns : Torch, socket wrench erroneously stopped winding when The rugged surrounding terrain promptly detected. If the required the sub-scale read 938 mbs, thereby made it virtually impossible to Darwin: Hose clamp checks had been properly carried making the altimeter over-read by reiach the site by surface transport Launceston: Aircraft door handle, metal bracket Debris picke::l up on the apron of a major airport. out on this occasion, the error in nearly 3,000 feet. Meanwhile the and a helicopter had to be used · Mangalore: Ait'craft jacking pad. the •altimeter setting would have captain set the correct QNH set­ for the inspection. been discovered before the aircraft Melbourne: Ball pein hammer, Weston thermostat, it would be tragic indeed if we had to wait for a ting on the port altimeter. At this fuel tank dipstick, pneumatic system part, fatality to punch home the vital importance of point the aircraft was cleared to Giving evidence, the first officer descended below the height to said that the incorrect setting of which it had been cleared. The signalling bat, pair of pliers, wheel chock, coil accounting for all equipment after work on an air­ 2,000 feet on QFE and the first of aerial wire, screwdriver. craft has been completed. officer checked the port altimeter 938 had given him a "visual ap­ captain's failure to ensure that this setting as 1020 mbs, called for the preciation" of the correct setting was done indicated an unsatisfac­ Moorabbin: Spanner This potential is horrible enough in itself, but landing check and closed t he of 839 mbs. Subsequently, in in­ tory standard of supervisiQn. Perth: Pair of multigrips another possible consequence could be even worse - throttles to descend. tending to cross-check the alti­ Port Mor esby: Length of copper pipe a situation where a forgotten piece of equipment meters by adding the aerodrome COMMENT Rockhampton: Screwdriver, oil drain tube becomes lodged in a position where it fouls a con­ At 10 nautical miles DME, on trol line or, by some similar cause, leads to loss of elevation to the starboard reading, Sydney: Aircraft jacking pad, length of % in. pipe, descent with the undercarriage ex­ he mentally substituted the height The first officer's undetected error control of the aircraft. And t his is no idle thought. tended, the !LS indicated "fly up", placed this a ircraft in a situa tion perilous toggle wrench, torch, t urbine engine test probe, of 2,000 feet to which the •aircraft wheel chock. As most of us know, it has happened ! while the first officer's 1altimeter had just been cleared. By an un­ almost beyond wo rds and it is little short There is one other "good housekeeping" aspect of indicated that the aircraft was fortunate coincidence, this hap­ of miraculous that the flight did not be­ The list of recovered articles is startling enough, aircraft maintenance, which though not likely to come just another apparently in exp Iic­ passing through 4,500 feet instead pened to be the difference in the but what of all t he others that are never found - lead to consequences as dire as the ones we have of about 3,000 as expected if on able disaster. Although the altimeter those that fall out of aircraft after they have taken been discussing, could nevertheless inflict costly altimeter readings. procedures used by the operator con­ the glidepath. Subsequently, the off ? damage to an aircraft, particularly one with turbine first officer looked ahead and saw The captain stated that, after cerned differ from our own, this in no engines. The photograph on this page shows an the runway and approach lights adjusting the port altimeter to the way detracts from the principte at stake. There is no way of knowing how many items there accumulation of debris picked up on the apron of The accident is a startling demonstra­ fused almost into a continuous QNH setting of 1020 mbs., he are in this category. Nevertheless, when we consider a major airport. It is not difficult to imagine the tion of how absolutely essential it is for that the time an aircraft spends manoeuvring on an line. Realizing he was too low, he checked the sub-scales on both in­ crews to properly monitor and cross­ damage that could be inflicted by some of this rub­ applied power but the aircraft struments but did not check the aerodrome is but a very minor fra:ction of the total bish if it were ingested by a turbine engine. check their instruments during a n a p­ flight time, and the fact that a number of the articles touched down on the ground and difference in the instrument read­ proach to land. A random check on the apron of a secondary air­ ran along for about three seconds. ings as required by the company's found were dropped from aircraft after they had port, made while this article was being written, indi­ The captain opened the t hrottles ope1,ational procedures. When the There can be little doubt that if it landed, it is reasonable to assume that articles are cates that the problem is not confined to major air­ to full power and the first officer captain last checked his altimeter were possible to know the true facts, being dropped in flight at least as frequently as on ports. One piece of twisted locking wire that was lifted the aircraft off. The captain befQre the premature touch down, many of the world's unsolved major acci­ aerodromes, and perh aps much more often. recovered from the tarmac surface of a light air­ reported that the •aircraft had "hit it read 7,600 feet on QNH., i.e., dents which have occurred during the Statistically speaking, if this trend continues, it craft parking area, could easily have punctured any something 8 miles out on final" and 2,273 feet above aerodrome level. descent or a pproach to land phases of is only a matter of time before a piece of equip­ flight could be attributed to mis- read or light aircraft t yre that ran over it, with the chance requested clearance for a visual He expected the aircraft to level ment drops where it is going to kill or maim some of a landing accident resulting. circuit and landing with emergency mis-set alti meters. This particular case out after this, and because he was gives us a rare opportuni ty to study innocent party on the ground. If an accident of Aircraft maintenance engineers have a reputation services standing by. While climb­ concentrating on the landing such an accident actually in the making. this nature were to happen, there is no doubt that for workmaship of a high order and scrupulous ing away on QNH, the first officer check, he· was not aware that the Let us not miss the vital lesson it con­ it would have a most salutary effect on the habits attention to detail. Why spoil that image by "slap­ realized he had mis-set his alti- descen t was continuing below tains. of aircraft maintenance personnel generally. But dash" cleaning up after the job is finished ?

24 AVIATION SAFETY DIGEST MARCH, 1 9 6 6 25 Some pilots are fastidious in their attitude to windscreen cleanliness and rub them over carefully before beginning each flight. Others are not so fussy and seem to accept that a bit of grime or mist on the windscreen doesn't matter much. If you are in this latter category wa tch out that the' coming winter months don 't catch you out in the same way as the pilot of the Cessna!

Below: After taxi-ing forward a few yards, this EP9 collided with a fuel drum, damaging its propeller. Even if t h e propeller had missed the dr um, the aircraft would still have run into the refuelling equipment. I nset: T he bent pr opeller. Both blades wer e damaged beyond repair.

It was just after first light, at a country aero­ before starting, as enjoined by the Daily Inspection drome in Western Australia, and the pilot of an EP-9 Schedule, the pilot would have seen the equipment had carried out his daily inspection and climbed from the cockpit and the accident would not have into the cockpit, ready to ferry the aircraft to an happened. agricultural airstrip for top-dressing operations. He Only a few days later, another dirty windscreen started the engine and let it warm and, after com­ was responsible for a more serious accident to an pleting a satisfactory run-up, he released the brakes agricultural aircraft: At Goulburn, New South Wales, and began to taxi. The aircraft was facing into the the pilot of a Cessna 180 and his loader-driver ar­ east and the rising sun, low on the horizon, made rived at the aerodrome early in the morning to fty visibility from the pilot's seat difficult. The aircraft to an agricultural airstrip. The morning was very had rolled only a few yards when the spinning pro-· cold with frost on the ground and the aircraft'~ peller struck an empty 44-gallon drum that had windscreen was completely misted over. Before start.­ :been used for refuelling the night before. The pilot ing, the pilot rubbed the mist off a small area of the straight away switched off the engine and braked windscreen directly in front of his seat. The two men the aircraft to a stop, but both propeller blades were boarded the aircraft and, after warming up, the already damaged beyond repair. pilot taxied out and began to take off. When the aircraft was inspected after the acci­ Forward visibility through the small "hole" dent, the windscreen was found to be extremely rubbed on the misted windscreen deteriorated as the dirty. This would have aggravated the blinding ef­ aircraft gathered speed, and the pilot lost direc­ fects of the sun, making it almost impossible to see tional control. At 40 knots he abandoned the take-off Extracts From Two Overseas Accident Reports - anything in front of the aircraft from the cockpit but the aircraft continued the swing to port and while taxi-ing into the east. It was also found that, finally ground-looped. The starboard undercarriage After making a walk-round inspection of his aircraft, the pilot of a PA.22 taxied out even if the propeller had missed the 44-gallon drum, leg collapsed and was torn away and both the star­ for take-off. The take-off run seemed normal but immediately after becoming airborne the aircraft became uncontrollable and crashed. it would have struck the pumping equipment that board wing and the starboard tailplane struck the been left in front of the aircraft. The pilot said later ground heavily, each being bent badly in mid-span. Investigation revealed that the aircraft's rudder was missing from the empennage. A that he had noticed the drum and refuelling equip­ Happily, neither the pilot nor his passenger part-owner of the aircraft said later that two days before the accident he had removed the ment when he arrived at the aerodrome, but not was injured, but as with the first accident, this rudder to have it repaired. seeing them after he boarded the aircraft he thought one could easily have been avoided if the pilot had * they were further away and not a hazard. It is very taken the trouble to clean his windscreen before A private pilot was practising* circuit s and landing* s in a Turbulent ultra-light air­ likely that, had he cleaned the aircraft's windscreen beginning his flight. craft. As the aircraft touched down on the fifth landing, the port wing fell off.

26 AVIATION SAFETY DIGEST MARCH, 1 9 6 6 27 ....

WATER IN THE FU EL?

An interesting fact about m1xmg of fuels was primary colours, red, yellow and blue, which mixed demonstrated by an amusing incident recently. It in the correct ratio will give an approximately also emphasised again the importance of correctly colourless mixture. So remember then that the checking fuel tanks for water. colour of fuels when mixed can be misleading and that positive ways to check whether the liquid = A pilot landed his aircraft which normally uses being drained is contaminated with water should 80/87 avgas at an aerodrome where only 100/130 always be used! octane fuel was available, and not wishing to con­ tinue his flight on partially filled tanks, proceeded to One satisfactory method is to drain the fuel into top up with the higher grade of fuel. a glass receptacle which already contains a small quantity of pure fuel. Water will not mix with the When the aircraft had been refuelled, the pilot fuel, regardless of its colour. Alternatively, samples set about checking his tanks for water in the normal can be checked by chemical means such as a water way, but only a colourless liquid, looking like water, detecting paper or paste, where a change in colour came from the drain cocks. He kept on, taking of the detecting medium will give a clear indication sample after sample, but still the colourless fluid of the presence of water. The distinctive smell of flowed out. Noticing what was happening, an L.A.M.E. fuel, its colour and its speed of evaporation are also came over and told the pilot he was draining off fuel, useful additional indicators, but if used alone can r.ot water ! When the pilot queried the lack of color, sometimes give quite the wrong impression . the L.A.M.E. pointed out that this is quite normal when 80/87 and 100/ 130 fuels are mixed. One final comment: We would not wish it to be inferred that indiscriminate mixing of fuels is of no The L.A.M.E. was quite correct. When these fuels consequence. On the contrary, it is not recommended are mixed in the appropriate ratio of 1: 3 a colourless as a normal practice. However, when there is no liquid results. The reason is that Grade 100/130 is reasonable alternative, no engine damage will result green in colour, the green being made up of blue from short periods of op·eration with mixed fuels, and yellow dyes. When this is mixed with the red provided the fuel added has a higher rating than of Grade 80/87, we then have a mixture of the three that specified for the particular aircraft.

Air Sense There are two danger peaks in a pilot's life. One is when he has flown one hundred hours and believes that he knows everything there is to be known about it. The other is when he has reached the three hundred hour mark and knows that he knows all about it . It is only later, when he reaches the two thousand hour mark, that he realizes he will never know all there is to be known ! The best pilots are not fo nd of "shooting up" buildings, landing off steep turns, low flying, and other forms of self-advertisement. They get on with the job vigorously, quietly, and efficiently, assessing situations carefully and avoiding risks whenever they can . All things which imply good airmanship mean conscious effort at first, from swivelling the h ead round to see th at it is all clear before taking off, to doing a final cockpit check before vacating the aircraft after landing. Later on, all these hundreds of small points become habit. They are the sign of a good pilot and they are covered without any conscious thought or effort, •and fit into a sense of what has sometimes been called mastery of the air. This advice is not intended to cramp your style. Pilots without vigour and initiative, are dull automatons who make a poor show in an emergency. What you are asked to do is to strike a happy balance between commendable enthusiasm and · sensible caution; to profit from the experience of others, that aeroplanes are excellent and willing servants when wisely and firmly handled, but treacherous and destructive when not controlled according to the basic laws of flying· •and common sense. (With Acknowledgement to " Air Sense," R .A.F. Directorate of Flying Training).

28 AVIATION SAFETY DIGEST