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Department of Civll Aviation .. Australia

PRINTED BY THE DOMINION PRESS. NORTH BLACKBURN. VICTORIA f / AVIATION SAFETY DIGEST + Department of Ci vi I Aviation · Australia

No. 47 SEPTEMBER, 1966 NEEDLESS TRAGEDIES

Contents It is our sad duty in this issue of Aviation Safety Digest to publish the reports of three fatal light aircraft accidents which together claimed the lives of nine young Australians. Editorial The sheer tragedy of these unforeseen and catastrophic finales to what amounted to Disastrous Low Level Steep Turn 2 pleasure flights, is heightened by the fact that none of them need have happened- all three could have been avoided if the pilots concerned had not chosen to disregard the very regula­ Fatal Demonstration Flight 5 tions that have been framed to prevent such accidents. In two of the accidents also, innocent Pilot Killed During Unauthorized Low Flying 7 young passengers had entered the aircraft at the invitation of the pilot, doubtless with every confidence in his ability and judgment, and were taken to their death as a result of this VTOL-Then and Now 10 misplaced trust- misplaced because the pilot either ignored, or failed to recognise the Aviation Safety Pictorial 14 weight of responsibility placed in his hands, by virtue of his command of the aircraft. Oleo Leg Maintenance 16 It is perhaps significant that two of the pilots involved, though properly qualified for the category of flight in which they were engaged, had less than 200 hours aeronautical experience Complacency can be Costly 19 and the third had not a great deal more. It has truly been said that the greatest danger peaks Report that H eavy Landing 20 occur in the first few hundred hours of a pilot's flying career - at this point he has learned to fly with confidence and tends to think he knows all the answers, but has not been flying long Unusual Landing Accident 21 enough to see that there is always something more to learn. It is at this stage that a pilot is Antenna Obstructs Trim Movement 22 particularly susceptible to the "It can't happen to me" philosophy and is strongly tempted to excuse his own flying standard in words such as "Rules were made for the obedience of fools Overseas Accidents in Brief 23 and the guidance of wise men", -never questioning that he could be in any but the latter Take Time to Think 26 category. Thought Transference? 28 This type of thinking cannot be refuted too strongly. It has no place in aviation and one has only to watch the most experienced professional pilots to see that this is a fact accepted by those most qualified to judge. Logically, if pilots with such a wealth of experience cannot afford to depart from accepted standards, how much less can the pilot 'vVith only a hundred or so hours? COVER: A Bell helicopter under charter from Ansett-ANA, This is the truth manifested time and again in fatal light aircraft accidents that speak for carrying personnel for tlie oi.l-drilling rig "Glomar III" in themselves. 13ass Strait, approaches the vessel's landing platform in boisterous weather. Yet arguments of this sort apparently do not convince, for still the attitude persists in some that they know better than "the book". But even if logic fails to convince, there is perhaps a chance that stark, shocking reality may sometimes succeed. To any therefore who have tongue­ in-cheek tendencies towards acknowledged standards of air safety, we commend a thorough study of the fatal accidents reported on pages 2, 5 and 7 of this issue.

Aviation Safety Digest is prepared in the Air Safety Investigation Branch and published quarterly. Enquiries and cont 'h 11 t' for publication sho1dd he addressed to The Editor, Aviation Safety Digest, Department of Civil Aviation Bo 1839Q p 0 Ertl'1 bionhs Street, MELBOURNE, C. l. ' x ' · ., .za et

R-cc~~~ for .that material wliich is indica~ed to h~ extracte~ from or based on another publication, in which case the authority of· thed origmato1d . . should. be sought,. . the material. . contained herem may' with acknowledgment' he freely reprod1t ee d in· p1i hl'1cations · mten e pnmanl~ for ctrculation in the Av10t1on l11d11stry. All other publication, whether by the printed word, radio, or television, mmt have the prior approval of the Department of Civil Aviation. SEPTEMBER, 1966 DISASTROUS • LOW LEVEL STEEP TURN

While making a steeply banked turn at low altitude around the homestead of a station property in South Australia, the pilot of a Cessna 175 lost control and the aircraft dived into the ground. Im­ pact forces and the intense fire that followed destroyed the aircraft. The pilot and the four children on board were killed.

The 6.ve occupants were guests height of about 200 feet, passed to The port wing tip had struck the at the station homestead where, with the west of the strip as it Rew back ground first, followed almost at once others, they were being entertained in the general direction of the home· by the nose of the aircraft, and the over a holiday weekend. The pilot stead. The father of two of the child­ ground marks and wreckage distribu­ was from another station property ren, who had observed the take-off tion indicated that there had been and had arrived in his aircraft the from the edge of the strip, wa tched no forward motion of the aircraft previous day. the aircraft Hy by and it was low after the initial impact. The centre Shortly before 6 p.m., while a enough for him to clearly see his son section had been subjected to severe number of the guests were relaxing waving from the left-hand rear seat. impact forces, which "vere followed on the lawn at the rear of the home­ O ver the southern end of the by fire of such intensity that many stead, the pilot offered to take the strip, the aircraft roll ed into a left components of the engine and the children for a flight. With his four turn towards the homestead and, as fuel tank and cockpit areas, had prospective passengers, compnsmg it approached, the pilot progressively fused into a mass of molten metal. the sons of the owner of a nearby steepened the turn to bring the air­ Both mainplanes, with the fuel tank station, and a girl and a boy who craft around the house. As the turn areas burnt out, were found in their were staying for the weekend with tightened and the angle of bank in­ normal position in relation to the their parents, the pilot left the creased, the nose of the aircraft fuselage. The Haps were fou nd ex· The steep angle of the final dive ing in further distortion of the blades, the south-western end of the strip homestead to walk to the aircraft began to drop and it lost height. The tended between 10 and 20 degrees. and the lack of forward movement there was still evidence of impact and the homestead to allow the child­ aircraft nosed down more rapidly as parked on the airstrip 150 yards be­ The fuselage behind th e luggage of the wreckage after the initial im­ damage suggesting that considerable ren on board to clearly see their the turn further steepened, and it compartment had folded to the left hind the house. pact, indicated that the aircraft w::is power was being delivered by the parents and others on the ground finally dived out of view on the but was otherwise generally intact. At the airstrip, the pilot seated his out of control, and probably in a engine when the aircraft struck the below. The aircraft's angle of bank other side of the homestead in a The engine tachometer and the pilot's eldest passenger next to himself in stalled condition. The wreckage ground. steepened as the turn progressed and near ·vertical bank and a steep nose· wrist watch were fotmd in the burnt the right hand front sea t, and had examination did not reveal any de­ it seems likely that the pilot intended down attitude. Almost immediately, out cockpit area. The tachometer T he pilot was 23 years of age and the other three share the rear bench fect which might have conh·ibuted to continue the turn to orbit at very there was a noise of violent impact was jammed at 2500 r.p.m. and the had held a private licence for two sea t, though it was fitted with safety to this loss of control. No signifi­ low level around the group on the and dense black smoke rose from wa tch had stopped at 1804 hours. years. During this period he had ac­ belts for only two passengers. He cant variation in the engine noise lawn of the homestead. To try and beyond the house. N o other readable instruments w.::re cumulated approximately 160 hours then started the engine, taxied to was noted during the latter stages of found. The only aircraft components flying experience - nearly all of it, achieve this, and at the same time the southern end of the strip and the flight and the jammed and burnt keep the people on the ground in * * * found away from the main wreckage including his flying training, in this after warming up, took off into the Investigation of the burnt-out were the lower section of the star­ out tachometer found in the wreck­ sight, the pilot may have tried to north. particular aircraft. wreckage confirmed that the air­ board door, found to the rea r of the age was indicating in the normal pull the aircraft into an extremely After climbing away, the aircraft craft had struck the ground while starboard wing tip and small frag­ engine operating range. Although From the available evidence there tight turn so the banked high wing made a shallow turn to the left on still in a steep nose-down attitude ments of perspex in and around the the propeller had been subjected to is little doubt that the pilot com­ would not obscure the view from the to a southerly heading, and at a and while banked steeply to the left. scorched area in front of the aircraft. intense heat after the impact result- menced a turn at low level around cabin window. It is possible that the

2 AVIATION SAFETY DIGEST SEPTEMBER, 1966 3 pilot would have been g1vmg some it is most unlikely that the pilot of his atten tion to the people on the would have been giving his whole ground, and perhaps pointing them attention to Hying the aircraft. out to the children on board, during The loss of height involved in re­ this progressively steepening turn. covery from a stall, entered under The stalling speed of the aircraft such circumstances, is substantial, would have increased rapidly as the and when the sequence is initiated at At a country aero club in N.S.W., a visiting pilot was demonstrating a Cessna 172 he was tu rn steepened. Manual data indi­ only 200 feet, the outcome is a fore­ hoping to sell to the club. Two young club members accepted an invitation for a flight, boarded the ca tes that the Haps-up stalling speed gone conclusion. aircraft with the pilot and they taxied out for take-off. Five minutes later the aircraft was a heap of this type of aircraft is 56 knots in There is an all-too-familiar ring in of burning wreckage and all three occupants were dead. a turn with 20 degrees of bank, rising the analysis of the aircraft's Right The stage setting for this wholly taxied out, the club pilot at the con­ climb to some 300 or 400 feet and to 62 knots at 40 degrees, and 76 behaviour up to the final dive and The engine tachometer as recovered from unnecessary tragedy had begun the trols in the left hand seat. The club carried out what appeared to be a knots at 60 degrees. Beyond 60 de­ impact-it has all been said before the wreckage. The needle is jammed i11 previous morning, a Saturday, when pilot took off into the west, carried stall turn to the left. During the grees, the stalling speed would, of in almost identical words. Indeed the 2,500 r.p.m. position. the pilot arrived with the aircraft to out a normal circuit, and turned ensuing dive, the aircraft did not course, increase even more rapidly. just 12 months ago, the Digest pub'. spend the weekend demonstrating it on to final approach . Turbulence recover as the watching pilots ex­ In the configuration in which the air­ Jished an account of a fatal accident to club members. The weather de­ had been moderate but now as pected, but with the nose still 60 craft was found, with the Haps that occurred in similar circumstances teriorated in the afternoon, and only they approached, the aircraft Bew degrees down, disappeared from sight lowered between 10 and 20 degrees, (see "Steep Turn, Low Altitude, In­ during steep turns, and explaining about an hour's demonstration flying into a severe downdraught. The behind an embankment and a few the stalling speed in a 60 degree attention", Avia tion Safety Digest the principles involved in the increase could be completed on the Saturday. downdraught lasted six or seven moments later black smoke rose up. banked turn would be in the vicinity No. 43, September 1965) . In this in stalling speed during turns (See seconds and the pilot had to add of 70 knots, increasing to 90 !mots accident, only one of the four occu­ "Watch Those Turns", Aviation Next morning, the pilot arrived at considerable power to maintain a as the angle of bank steepened to 70 pants lost his life, but only for the Safety Digest No. 44, December 1965). the aerodrome at 1000 hours. After uniform rate of descent. A normal Subsequent examination of the degrees. A steep turn of this order reason that the aircraft dived into carrying out a daily inspection, the T here is one other consideration landing followed, and as they rolled burnt-out wreckage at the scene of requires the full skill and the undi­ wa ter and not into solid ground. pilot invited the chief fl ying in­ which, though it did not directly to a stop on the strip, the demon­ the crash did not reveal any defect vided concentration of the pilot to As a sequel to that accident report, structor to use the aircraft as he contribute to the cause of this acci­ strator pilot invited the other to or malfunction which might have maintain a level Bight path. In this the Digest published a special article wished, but for the most part during dent, is nevertheless indicative of change seats and he would "show contributed to the accident. The air­ case, with the aircraft turning at in th e following issue, discussing the the morning Bew it himself, taking laxi ty in the pilot's flying discipline. the boys these stall turns of mine''. craft had struck the ground while very low level over a group of people, dangers of stalling and losing control as passengers any club member who The Flight Manual for the Cessna The club pilot declined and they rotating to the left in a steep nose­ wished to go for a Bight in the air­ 175 states that the maximum number taxied in. down attitude, the initial impact being craft. of occupants shall be four persons. Back in the club house, the club taken by the port wing. After the The burnt 011.t wrec/wge of the aircraft. The homestead around which the aircraft was Air Navigation Order 20.16.3.11 After lunch he made another £1.ight, pilot mentioned to other members he main impact,taken on the nose, the turning is in the bacligrou.nd. stipulates that two children may then handed the aircraft over to the had been invited to go and do stall aircraft had bounced and slid for 30 occupy one seat when their combined chief ilying instructor. T he wind had turns, but had refused because aero­ feet and come to rest upside down. weight does not exceed 170 lbs., but strengthened and was now blow­ batics made him airsick. Soon after­ In a statement later one of the in this case, the combined weight of ing from the west at about 15 wards, the demonstrator pilot came club pilots who had witnessed the the smallest two passengers was not knots with gusts in excess of 20 into the building and issued a general final manoeuvres of the aircraft, said less than 200 lbs. In carrying his knots. As a result, the chief flying invitation, 'Who's for stall turns?" that earlier in the day he and another Two young student pilots agreed to fo ur passengers, therefore, th e pilot instructor found, during his ap­ passenger had accompanied the pilot go and the three left the club house. on a flight over the town. T owards disregarded the requirements of the proaches to land, that there was a Minutes later, pilots watching the end of the £1.i ght, as they were aircraft's Flight Manual and there­ severe wind gradient on the eastern from the cl ub house saw the aircraft re-entering the circuit area at about by contravened Air Navigation Regu­ side of the aerodrome, and formed take-off into the west. After it had I 500 feet, the pilot had pulled the lation l I2A(3). the opinion that for students it was a "dual only" day. climbed normally to about 500 feet, aircraft up into a stall turn to the A few months hence will the it performed a wing-over to the left left then dived to cross the aero­ Digest have the distasteful task of When the chief Bying instructor and dived back towards the strip. drome at 150 feet. At the end of this reporting yet another tragedy result­ landed at the end of his second Bight, The aircraft eased out of the dive mn he had again pulled the aircraft ing from steep turns at low level? the demonstrator pilot was waiting as it crossed the aerodrome boundary up into a climb, allowed the speed The Department will go on doing all with another club pilot who wanted and made a fast downwind run over to wash off, and then at 500 feet it can to prevent such disasters, but to try the aircraft. The chief flying the length of the strip at about 40 with a stall warning blowing, let the the real answer to the question lies instructor warned them to watch out feet. Soon after passing the eastern aircraft "drop off" to th e left, closing in YOUR hands. for the wind gradient, and they boundary, it pulled up into a steep the throttle as he did so. The pilot 4 AVIATION SAFETY DIGEST SEPTEMBER, 1966 5 ------~-

applied opposite aileron to level the wings as they dived almost vertically, then eased the aircraft out of the dive and landed straight ahead on the strip. The pilot had given the pas­ sengers no warning of his intention to perform these manoeuvres. There is little doubt that when the accident occurred, the pilot was attempting to emulate this earlier performance. The reason why he didn't get away 'vvith it the second time is probably twofold; firs tly, the c: !! 0 0 pilot had begun the manoeuvres

-u ~c: from climbing speed at only 500 feet, ~ I(') as against cruising speed at some "'ON I 1500 feet on his earlier attempt, and "'O 0 c: N secondly, the increased wind strength and the pronounced downdraught on the lee side of the aerodrome would have had the effect of increasing the amount of height required to recover level Right. ' Good airmanship, caution and adherence to safety regulations are necessary ingredients of a safe opera­ tion and accidents of this type almost invariably point to omissions in these areas. This accident is no exception and other accidents covered in this issue of the Digest follow the same pa ttern. In this instance there is no better summary than the following It was a fine spring morning at an quested the pilot to check the aircraft, shortly afterwards, he climbed into quotation from the formal conclusions aerodrome in northern Victoria. Soon and in particular the fuel before he the aircraft and started the engine, of the investigation: after 0900 hours a young pilot mem­ departed. T he pilot carried out a taxied out and took off. "The pilot carried out an acrobatic ber of the local aero club, arrived to Right lasting an hour and 40 minutes, manoeuvre which was prohibited do some Hying. The chief Hying in­ and returned and landed at 1120 Thirty miles to the south-east, in a under the terms of the aircraft's structor was away for the day and hours. valley at the foot of the northern Certificate of Airworthiness and only the office staff were in attend­ slopes of the Great Dividing Range, in doing so he contravened Air ance at the club's office, but a part­ After lunch, at about 1400 hours, a young fa rmer was mowing a pad­ Navigation Regulation 131 (2)(b). time club instructor, who also ran a the pilot presented himself once more dock on his father's property. Sud­ The acrobatic manoeuvre was car­ business in town, was on call for any at the aero club office and sought denly, the whine of a light aero ried out at a lower height than instructional work that might be re­ permission to make another flight. engine drowned the noise of his 3,000 feet above the highest point quired. At the pilot's request, the club Again the office rang the instructor h·actor and a Victa Airtourer Hew of the terrain, countrary to the office telephoned the instructor to ob­ and obtained his authorization fo r the very low in front of the tractor's prov1s1ons of Air Navigation tain his approval for the pilot to take Hight. The pilot signed the club's path. T he aircraft's sudden, unex­ Regulation 13 1( 3)(a). one of the club's Victa Airtourcrs for a daily Hying statement, indicating he pected arrival came as no real surprise CAUSE: The probable cause of the accident was that the pilot local Right. The pilot held a restricted accepted the aircraft for a local flight - he knew who the pilot would be. attempted an acrobatic manoeuvre private licence so the instructor in the training area, and that it had T he pilot was engaged to his sister at an unsafe height." authorised the Right verbally and re- 12 gallons of fuel on board. Very and a number of times in the past

6 AVIATION SAFETY DIGEST S EPTEMBER, 1966 7 few weeks had Bown low over the It passed just to the south of his posi­ ma rk s to be recognisable, bu t it is property, waggling his wings. The tion and turned on to a northerly evident that it was this part of the young farmer got on well with his heading. The engine note decreased aircraft that struck and broke the wire. prospective brother-in-law and on and the aircraft entered a shallovv one occasion had gone Hying with dive. As it descended, the wings T he power line that the aircraft him in the Victa. "moved up and down fa irly rapidly". struck is one of two single-wire The manager watched the aircraft branch lines crossing the property. The aircraft seemed to be flying until his view of it became obscured The heigh t of these branch lines is 36 nearly straight and level as it Bashed by trees. A moment later there was a feet. A main high-tension line, carried across in front of him. He turned his loud "twang" from the single-wire on steel pylons 120 feet high, also head to follow it and was shocked power line that ran from his house crosses the property 200 yards south to see it slice through a single-wire of where the accident occurred, and power line running parallel to the northwards in the direction the air­ craft had taken and the power line the aircraft would have passed over tractor's path. The power cable this main line as it dived towards the snapped and fell to the ground and vibrated violently. The aircraft came into sight momentarily, apparently in tractor. (See fl ight path photograph.) at the same time the engine noise a steeply banked diving turn to the Although the main power line would ceased abruptly. The nose of the air­ have been clearly visible to the pilot, craft rose, the port wing dropped left. It disappeared from view again and there was a noise like an explo­ the lower, single wire line would and the aircraft rotated to the left have merged with the background and struck the ground with the star­ sion. He at once began to run to the scene of the crash. and been almost impossible to see board wing tip. The wing crumpled, from the aircraft. the nose slammed into the ground Examination of the wreckage, and and the wreckage skidded to a stop T he pilot was 20 years of age and impact marks on the ground, showed and caught fire. Jumping from his held a restricted private licence. His that the aircraft had struck the tractor, the farmer ran towards the total flying experience amounted to ground first with the starboard wing, burning aircraft. As he approached 130 hours, of which more than 50 while in a steep nose-down attitude. there was an explosion in the wreck­ had been flown in Victa aircraft. As The first point of impact was 210 feet age and the Barnes leapt up more the holder of a restricted licence, the Aerial view of accident site showing approximate final µiglit path. beyond the broken povver line. T he fiercely. He ran to the homestead for pilot was authorised to fly "in com­ assistance. wreckage had then bounced and slid mand" only within fi ve miles of his for 30 feet before coming to rest. The departure aerodrome or within the Minutes later, the manager of the tail section and the outer port wing, confines of the flying training area 'vvhich the aircraft crashed, to whose one stage of a flight that he had made adjoining property, who had also seen ing to see the wire in time to take which had been pulled away from assigned to that aerodrome, except the aircraft crash, reached the scene. daughter the pilot was engaged, said with him three weeks before. Nor­ avoiding action, could not be fi nally the fire in the attempt to save the when engaged in an approved solo The wreckage was still well alight that the pilot had formerly worked mally, however, the pilot did not determined. T he evidence of the pilot, had sustained relatively little but the height of the blaze had cross-country navigational exercise. on his property for several months come lower than just above the height investigation quite clearly indicates, damage, but the remainder of the air­ The point where the aircraft crashed passed. H e pulled away the port and would have been fa miliar with of the main power line pylons, which however, that the pilot ignored the craft had burned to destruction. is some 16 miles beyond the boundary wing, still on fire at the root, the tail the positions of the power lines. In cross the property, and are about 120 area limitations endorsed on his pilot There was, however, no evidence to of the training area concerned, and as assembly and the blazing cockpit the weeks preceding the accident, the feet high. licence and then flew the aircraft suggest that a loss of engine power or canopy, then covering his hands and the pilot had not been authorised to pilot had flown low over the property over the property of his prospective any defect in the airframe had con­ T he evidence given by the man­ face with clothes, dashed into the make a solo cross-country training on a number of occasions, and had father-in-law at an unsafe height, in tributed to the accident. ager of the adjoining property, burning wreckage and dragged the fl ight, his action in flying outside the made a practice of waggling the disregard of Air Navigation Regula­ area was a breach of Air Navigation wings at any member of the family he describing the last minute of the fa tal tion 133 (2)(b). pilot free. It was too late. Although there were no impact Regulation 50(1). There was ample happened to see working there. fl ight, is consistent with the pilot * * * marks on the virtually intact port wing evidence that the pilot was familiar throttling back the engine and diving T he accident is another sad ex­ The manager said later that at the and tailplane, or on the propeller, with the boundaries of the training The son of the owner, who was towards the tractor driven by the son, ample of a pilot failing to appreciate time of the crash he was working in some 12 feet of the broken power line area and with the limitation en­ driving the tractor when the aircraft waggling his wings as he did so to that Regulations are framed to pre­ a cattleyard near his house about a was smeared with paint matching the dorsed on his Bight crew licence. crashed, also gave evidence that the attract attention. Whether the colli­ vent such accidents and failing to quarter of a mile south of the crash colour on the wing and tailplane. The pilot had frequently flown low over sion with tl1e power line resulted recognise that his skill was not com­ site. H e saw the aircraft, lower than destruction of the starboard wing by Giving evidence during the investi­ the property, waggling the wings. H e from an error of judgment or was the mensurate with his own estimate of normal, approaching from the west. fir e was too complete for any impact gation, the owner of the property on said the pilot had also flown low at result of the pilot forgetting and fail- his ability.

8 AVIATION SAFETY DIGEST SEPTEMBER, 1966 9 that on a rotor in forward Right, the advancing blade We are all painfully aware of the disadvantage inherent moves at a velocity of the blade rotational speed plus the in fixed wing operations in having to maintain a mini­ aircraft's speed, whilst the retreating blade has a velocity mum airspeed to sustain flight, but with the helicopter, of the blade rotational speed minus the aircraft speed. this difficulty has been reduced to a minimum. Surely T his produced a lopsided lift effect over the rotor disc then, a far better record might be expected. , which resulted in a startling chain of slow rolls in early We believe that the problem of the helicopter's high helicopter Rights. But, beginning with the introduction accident rate is primarily one of airmanship coupled with of Cierva's corrective "Happing hinge" mechanism, rotor critical operating conditions. If the standard of the former craft have been evolved and improved to the stage where can be raised to a sufficiently high degree, the effect of there are now many thousands of advanced VTOL air­ the latter will be minimised. From this viewpoint, there­ craft in operation. fore, let us examine three basic manoeuvres, at least one The evolution of the helicopter from the time of da of which is nomally employed in some form during field Vinci to the present day, spans some 450 years. But operations by the helicopter pilot. We offer comments on what of the men in whose hands the success or other­ each- not suggesting that they are comprehensive sum­ wise of all these operations has finally rested - the heli­ maries but rather points which should be considered by copter pilots themselves? Can we trace the development the pilot during that particular operation. of the pilot in the same way as we can the complex machine he fl ies? Perhaps at least we can draw an CONFINED AREAS analogy, embracing a much wider span of time, if we "In attempting a take-off from a clearing si tuated start with the mythical Icarus who is alleged to have amongst trees, the pilot lost translational lift due to in­ flown for a time with feathered wings waxed to his back! correct assesment of operating conditions. The helicopter For in one unfortunate respect there is a distinct parallel struck a tree and crashed to the ground." between this hero of Greek mythology and today's heli­ (D .C.A. Accident Summary.) copter pilot. Like Icarus who, bent on glory, flew too close to the sun only to plunge earthward after several Any consideration of confined area operations must pounds of wax had melted from his wings, so too do include landings as well as take-offs. Although the actual many of our present-day helicopter pilots display similar take-off phase is the more critical in a confined space, indiscretions. As a nett result, helicopter operations in any such take-off has, of course, to be preceded by a Australia have been marred by an unfortunate history landing. H aving made the landing, the pilot is then of major and minor accidents, as illustrated by the fol­ virtually committed to the take-off. Thus, the decision lowing table. Certainly some of these occurred as the to land in a confined space is also a highly critical one, V.T.O.L. then and now result of mechanical failure, but a high percentage can and, wrongly made, can indirectly be a factor contribut· be attributed to the pilots involved. ing to a take-off accident. For this reason the two opera· tions should be considered together. Major accidents Proportion H elicopters today in Australia, as in other parts of the designed the world's first helicopter, or, as it was known No. of resulting in sub­ of major What happens then when a pilot decides to make a world, are a familiar part of the aviation scene. Indeed, then, the Helixpteron - "helix" meaning spiral and Year H elicopters on stan tial damage; accidents to landing in an unprepared clearing? Does he make a so commonplace have they become, and so essential to "pteron" meaning wing. That the Helixpteron became no ending Australian Civil or complete total Heli­ quick "eyeball" appreciation then commit himself to an a great variety of specialized tasks, that it is sometimes more than a drawingboard notation lay more in the Register destruction of copters on approach? Is his subsequent take-off from the site just difficult to realize how recently the helicopter has be­ fault of the age rather than the designer. the aircraft Register as perfu nctory? Or does he set about the whole operation come a practical reality. Yet although it has come in to with the professional approach that both the expense of From the time that da Vinci sowed the seed of ver­ Jan . 1961 12 3 1:4 prominence in this way only over the past few years, his machine and the lives of his passengers warrant? tical Hight, history has been marked by developments 1962 14 2 1:7 the helicopter is, in fact, the result of centuries of Unfortunately, in many cases the old maxim "Familiarity and failures as man probed the potentialities and uncer­ 1963 19 3 1:6.3 development. breeds contempt" prevails, and in the interests of false tainties of celestial freedom. Significa nt milestones in 1964 30 4 1:7.5 economy or downright laziness, the first method is On his death in 151 9, the renowned philosopher­ helicopter development, however, were few and far 1965 41 11 1:3.7 employed. scientist of the Renaissance period, Leonardo da Vinci, between until the early 20th Century brought Juan left nearly 5,000 pages of manuscript, etc., revealing his de la Cierva into the field. Hitherto, designers working As can be seen, these accident figures do not take into Operating a helicopter in a confined area requires a extraordinary imagination and wide range of interests. on rotary aerofoils had been plagued by an inexplicable account the numerous reported minor accidents and high degree of handling skill, plus a comprehensive N ot the least of his talents was devoted to the theory of tendency for their crude models to roll uncontrollably to incidents that also cloud the industry. What is the reason understanding of the aircraft's performance and capa· Hight- the Hight of man -hitherto a dream existing one side as soon as horizontal Hight was attempted. The for this high proportion of destruction on a type of air­ bilities. Sound judgment of obstacle gaps, wind velocity only in mythology and imagination. About 1500 he reason for this, as Cierva correctly deduced, was the fact craft with such recognised safe handling characteristics? and direction, approach and take-off gradients, density

10 AVIATION SAFETY DIGEST SEPTEMBER, 1966 11 height, etc., requires many hours of lield experience. It rotor struck the ground causing the helicopter to over­ sure that, prior to touchdown, the helicopter maintains is good practice for a pilot to develop, and adhere to, a turn." (D.C.A Accident Summary.) translational lift. During the actual touchdown run, suitable standard drill when flying confined area opera­ \?\!hat is there about a mountain landing that creates direction may be maintained by cyclic control, and head­ ti ons. T o be worth,,,vhile, such a drill should include the problems for helicopters? Firstl y, there is usually an ing by anti-torque control - provided, of course, that following checks:- associa ted confined area problem such as that discussed rotor r.p.m. is maintained until the ground run has High Check for wind (velocity, direction and in the preceding section. Secondly, there is the high ceased. Soften the touchdown by a smaH application of Reconnaissance: gradient), availability of forced landing density altitude usually encountered in mountain flying. collective pitch and ensure that the skids are level and aligned along the direction of flight. areas, obstacles, ground condition (sur­ Finally, and probabl y most critical, there is the turbu­ Wind ~ fa ce, slope). lence almost inevitably associated with helipads located . Direction T he take-off run should employ the maximum dis­ Low (Incorporated in Approach): Confirm in mountainous or rough terrain. tance available into the prevailing wind, if any. Lift the Reconnaissance: high reconnaissance findings, select As with confined area operations, the time spent helicopter off the ground as soon as practical after h·ans­ touchdown point, gauge wind effects. during the aerial reconnaissance phase of the manoeuvre lational speed has been obtained - this reduces drag and IF DOUBTFUL - OVERSHOOT. increases manoeuvrability. Pay close attention to mani­ is a good investment. If there is any doubt about the ""'-·-·- · iI Ground Confirm wind direction, plan take-off helicopter's performance at the high altitude, it is a good Diagram illustrating approach path rncommended far a landing fold pressure; overboosting and overpitching is a preva­ Reconnaissance: path, plan hover path, lay guide policy to perform a power check-a slow fl ight at 40 on a pinnacle. By approaching slightly out of wind the heli­ lent malpractice during this phase. markers if necessary when manoeuvr­ copter is hept away from much of th.e turbulence in the lee of to 45 knots over the pad at abou t 100 feet will give a the pinnacle. Where density height and all-up -weight are critical, ing close to obstacles. good indication. If the engine power still in reserve keep control changes in flight to a minimum and where T ake-off: Perform magneto check, pre-plan during this manoeuvre is less than three inches of mani­ On take-off, a loss of lift may be encountered as the possible make all turns at half rate with the airspeed abort action to be taken in event of fold pressure, there will most likely be insufficien t power helicopter moves from the pad over the edge of the pin­ restricted to a slow cruise. T his reduces the possibility emergency. for landing and taking-off. T his, of course, is a rough nacle and leaves the ground cushion . In these circum­ of retreating blade stall, a condition that could develop guide only and it will vary slightly from aircraft to air- Confined area operations have taken toll of more air­ stances, airspeed is more important than height, and a quite easily with the rotor blades working at the large craft than any other manoeuvre in helicopter aerial work. craft. · nose down attitude will have the dual advantage of angles of attack inevitable in critical circumstances. If If in doubt about the outcome, don't attempt the land­ In anything in excess of light \i\rind conditions, there quickly gaining airspeed and also lifting the tail boom there is any doubt whatever as to the ability of the heli­ ing; undersell the helicopter rather than oversell yourself! will probably be turbulence and wind gradien t effects. clear of the edge. copter to perform within prescribed limits during and It is a good rule, therefore, when approaching a pinnacle after take-off, the wisest action any pilot can take is to PINNACLE OR MOUNTAIN OPERATIONS in such conditions, to make the approach slightly out of CRITICAL LOAD CONDITIONS reduce the payload. It pays dividends in the long run. "During practice high altitude take-offs and landings wind (see diagram). This keeps the helicopter out of "During a running take-off from a clearing, the air­ from a mountain ridge in strong wind conditions, the the tu rbulence for as long as possible and also allows for craft was lifted off the ground below effective transla­ It may be argued that this discussion barely scratches pilot failed to correct for lateral roll on lift-off. T he main better manoeuvrability in the event of an engine failure. tional lift. Further application of collective pitch resulted the surface of the subject and some competent rotary in rotor r.p.m. decay and the aircraft struck trees." wing pilots may feel justified in criticizing it as "teaching (D.C.A. Accident Summary.) one's grandmother to suck eggs". If this is so, perhaps we As the seasoned rotary wing pilot will know, the situa­ can be pardoned if we point out that the flying experi· tion may be encountered where a helicopter is correctly ence of the 23 pilots who were involved in the major accidents listed on page I I averaged 4046 hours per loaded within all-up-weight limitations yet has insuffi­ pilot! cient power to hover. The reason for this, of course, is a combination of high gross weight, high density altitude The helicopter industry is a rapidly changing one and and calm wind conditions. By referring to the perfor­ pilots should aim to keep pace with the new capabilities mance chart for the aircraft, the take-off or landing and limitations that the modem helicopter presents. • distance to clear a 50 foot obstacle may be obtained. Development, in most cases, breeds complexity, and this Nevertheless, there may be occasions where such a in turn requires constant familiarity with the aircraft for chart is not available, or even produced, for that particular efficient and safe operation. helicopter operation . In this case, a landing or a take-off It is a temptation to become blase about helicopter should only be attempted in an emergency situation. flying; it is easy to become dangerously overconfident. T o perform a successful running landing, the condi­ Unfortunately, in these aircraft, is not quite so easy tion of the ]anding strip surface must first be accurately to get out of an emergency situation resulting from an determined. If the area is unfamiliar, make a low flight error of judgment. A higher standard of pilot technique, reconnaissance over the touchdown area. A slippery coupled with a greater sense of responsibility, will go a grassed surface is perhaps the ideal, while dry rocky long way towards improving the present rather dismal ground should be treated with the utmost caution. En- helicopter accident record.

SEPTEMBER, 1966 13 Aviation ~afety PIC~TORIAL

GONE WITH THE WIND (Left) Beware DON'T BE IN SUCH A HURRY (Right) now that boisterous equinoctial weather is with us The pilot of this Mooney retracted the undercarriage again! This is what wind did to a privately owned immediately it became airborne on take off from Perth Tiger Moth, despite the fact that it was tied down! Last airport. The aircraft sank as the wheels came up; the year two agricultural aircraft, both Cessna 180's, also propeller hit the runway, and the pilot carried out a suffered. One, parked on a strip while storms were wheels up emergency landing straight ahead. Damage moving through the area, was swung from its position was confined to the bent propeller and minor abrasions by a sudden wind squall and the port wing was dashed to the underside of the fuselage. The pilot evidently against a tree. The other 180, was parked with wheels retracted the undercarriage before establishing a positive chocked and brakes hard on, on a strip in hilly country rate of climb. The Mooney owner's handbook states while the pilot was helping his loader-driver make re­ "on take-off, do not touch the (undercarriage) handle pairs to their vehicle. The wind, which was blowing ... until you have a safe airspeed and are sufficiently across the strip, increased to over 20 knots while they high above tl1e runway to avoid sinking back on the were working causing the aircraft to jump the chocks. ground." The pilot admitted he had been making a Blown by the wind, it then skidded down into a deep practice of raising the undercarriage immediately the gully to one side of the strip, tearing off the tail plane aircraft became airborne. and one undercarriage leg.

COLLAPSED FUEL TANK (Right) This was what a L.A.M.E. found when he inspected a Cessna 337 at Port Moresby after the pilot had reported that the fuel gauge was BIRDS AMONGST THE BARRELS (Below and Right) And making them- inaccurate. Wasps were the culprit. They had built a mud nest selves at home too! This is but one of several instances of birds trying to nest inside in the air vent line, and as fuel was drawn from the tank, atn10s­ the cowlings of aircraft left in the open, in some cases for only a few hours! On one pheric pressure compressed the walls of the tank, substantially occasion, the nest had been built in the air intake hose leading to the exhaust muffler reducing its capacity. shroud, and it caught fire when the engine was shut A similar incident a few months ago led to a complete loss down after a cross-country !light. The fire was quickly of power on one engine of a Piper Twin Commanche. This doused with a C02 extinguisher. The pilot had made time distortion of one rubber fuel cell caused the contents gauge a complete pre-Hight inspection before taking off and to indicate % full when it was actually empty. The pilot was had not seen any obstruction in ilie air intake. The able to re-start the engine after switching tanks. After landing a nest bad evidently been built well down the air intake visual check of the offending tank vent did not reveal any sign hose and out of sight. of an obstruction, but a piece of wire poked up the vent dis­ lodged a wasp's nest deep inside the wing.

UNUSUAL OBSTRUCTION (Below and Right) The mown grass shown in iliese airport pictures was responsible for delaying a Britannia for two hours. The aircraft was taid-ing to the terminal when mown I grass at tlie edge of the taxiway was caught in the slip-stream and ingested into the engine where it obstructed 1· the engine air intakes. The presence of the grass in the engine was not detected until the aircraft was pre- paring to take-off. l · It is probably not gznerally realised that mown grass j can pose an ingestion ha-iard to all turbine powered air­ craft and to turbo-props in particular. This is especially so when large aircraft are using narrow taxiways and grass at the sides is freshly mown. Mown grass can also I pose a problem with helicopters if it is whipped up by the rotor wash and drawn into air intakes. OLEO LEG

T orque linhs as fitted to some types of light aircraft oleo legs. The sequence shows haw the !inks can be fractiired in over-extension, as is !ihe!y to occnr if the rettim strolte of the oleo leg piston is not adequately dampened. The torque links are fti!ly extended in the photograph at left. Fractiirn of one of the linlts is inevitable as they are forced beyond this ftr.lly extended position.

Analysis of a number of accidents to aircraft that have cylinder, and the smaller one as the piston . The piston is then pulled right down to the cylinder stop and pushed wheels empty, the strut is inflated until the piston ex­ involved the failure of oleo shock absorber undercar­ is usually retained in the cylinder by either a large back to the fully compressed position . This process tends to the length specified by the makers. Checks riages, indicates that incorrect maintenance is frequently circlip or a gland nut on the lower end of the cylinder, should be repeated several times to ensure that air has should be made for air leaks around the valve and for a contributory cause. The most common fault has been although on at least one type there is no mechanical stop been completely purged from the strut, after which the oil leaks around the lower end of the cylinder. lack of oil in the strut, leading maintenance staff to within the strut itself. The circlip or nut, where fitted, oil level should be checked again with the strut com­ The strut contains an oil metering system which not over-inflate the strut to restore it to its correct inflated forms a stop for the piston, but is not usually intended pressed, and oil added, if necessary. When filling some only controls the rate of compression when the strut is length as measured on the exposed portion of the piston to carry any of the loads imposed when the strut is in types of struts after assembly, it is essential that the loaded heavily, as in a hard landing, but resh·icts the tube. T he purpose of this article is to explain, in general operation. In service, the extension of the strut is torque links be disconnected to ensure that the piston rate at which the strut extends again. This ensures that terms, the basic principles of the oleo shock absorber generally limited by torque links, attached to the strut can be moved all the way down to the stop in the the energy absorbed by the strut in a very short period of strut and to emphasise the necessity for mai ntaining the to also prevent the piston rotating within the cylinder. cylinder. If the torque links are left connected 'vvhile time is released at a much slower rate. If this feature oil level and air pressure within the proper limits. The Finally, an oil tight seal is provided on the lower end these struts are being filled, the piston will not go down were not present, the strut would release the energy at article is not intended to descibe any particular strut, of the cylinder, between the cylinder and piston tubes. su ffi ciently far to allow the oil to displace all of the air, the same rate that it absorbs it, causing the aircraft to since there are several types in common use today and The assembled strut is installed, with th e upper end of and there will be an air space below the piston. This bounce. It would also cause the piston to move rapidly the same general principles apply to them all. Rather, the cylinder fastened to the aircraft structure and the space must be filled with oil and the procedure outlined and under very high pressure, to the extent permitted it is concerned with correct day to day maintenance by wheel assembly located at th e lower end of the piston will ensure that it is done. Once the strut has been either by the piston mechanical stop or the torque links. pilots and maintenance engineers, many of whom may tube. correctly filled, however, it is not necessary to disconnect This would ultimately lead to fracture of the torque have gained the bulk of their experience on aircraft with the torque links during routine maintenance inspections, Filling instructions for oleo struts are usually set out links and/or the failure of the gland nut or circlip in undercarriages employing rubber shock cord, coil spring, unless, of course, the strut packings leak and allow the in th e maker's manual or may be found on a plate at­ the lower end of the cylinder. The inevitable end to or spring steel, shock absorber equipment. strut to lose a large quantity of oil. tached to the strut. H ydraulic fluid is poured in through this sequence is that the piston and wheel drop out of The shock absorber struts used on the majority of the the air valve plug hole at the top of the cylinder with When the strut has been correctly filled, the air valve the cylinder and separate completely from the aircraft, popular light aircraft today consist basically of two steel the sh·ut fully com.pressed and upright, until the strut is plug is replaced and the torque links where fitted are and the pilot is left with only the cylinder in place of a tubes, the large one being generally referred to as the completely filled. W ith the strut still vertical, the piston re-connected. Then, with the aircraft standing on its 'vvheel on which to make the best landing he can.

16 AVIATION SAFETY DIGEST SEPTEMBER, 1966 17 With a properly filled and inflated strut, the stroke spring; providing a cushion for the aircraft to ride on of the piston is such that it will accept landing shocks during ground operation, as well as sharing in absorbing Pi lot Contribution before it reaches the full extent of its inward travel, or the landing shock. It also serves to return the strut to ''bottoming" as it is more colloquially known, and there its fully extended position against the friction of the seal COMPLACENCY will be sufficient oil for the metering mechanism to con­ and packings when the aircraft becomes airborne. If the trol the strut during the return to its normal position. If strut is under-inflated, it will compress to a greater extent the oil level is permitted to fall below the specified on landing, and in extreme cases the limit of travel will can be COSTLY level, the recovery stroke will not be properly controlled be reached. A strut in this condition leads to mishaps and the conditions leading to the failures already de­ in the form of damage to the airframe, bent propeller To a private pilot with several years' scribed will be initiated. It naturally follows that the tips, ground looping, etc. Over-inflation restricts the S ervice experience behind him, a flight from lower the oil level, the sooner the failure will occur. movement of the strut in that it is forced continually Bankstown to Canberra looked " a piece of Once the strut has been properly filled, it is usually against the maximum extension of the torque links or the cake". But an embarrassing surprise sufficient to deflate it periodically and check that with mechanical stop within the strut itself, and the end brought home the fact that piloting ability the strut fully compressed, the oil level is as recom­ result of this battering is much the same as if the oil level alone is not always enough! It is to his credit mended by the makers. This check can be conveniently were too low. that he has written this frank account to carried out during 100 hourly inspections, but should Neglecting oleo strut maintenance has been res­ spare others a like predicament. be made more frequently if there is reason to suspect ponsible for at least three very expensive accidents, two oil is leaking from the strut. Any leakage will most prob­ of which could easily have inflicted serious injuries to ably take place on the piston tube and since leaks the occupants of the aircraft. It would be hard to say I had planned to fly a club aircraft from Bankstown By the time I was abeam Goulburn, however, all this develop fairly rapidly once they reach this stage, it is how many cases of minor damage, such as bent pro­ to Canberra and return, VMC below 5,000. As I have was forgotten. T he aircraft was on track, on time, and advisable to have the strut inspected and, if necessary, peller tips, have resulted directly and indirectly from held a priva te licence for eight years and flown some everything was seemingly on the ball. I was thoroughly 2,000 hours, most of it in Army light aircraft in Aus­ pleased with myself and looked forward to a cup of overhauled whenever leakage is evident. this same cause. tralia and South-East Asia, it might have been expected coffee in Canberra. It was not until I was approaching H aving discussed the function of the oil in the strut, Oleo undercarriage struts work hard. Give them the that any tendency to negligence on my part would long the Canberra Control Zone boundary and Sydney in­ the work done by the air compressed in the strut may attention they deserve and avoid adding to the De­ since have been eliminated. But as subsequent events structed me to call Canberra on 11 8.7 that my embar­ now be considered. Its purpose is much the same as a partment's accident statistics! showed, this was fa r from the case! rassment began. At this stage, rather than admit to Sydney that I had found that I did not have 118.7, I acknow­ Always having had plenty of radio equipment in ser­ ledged, then began a frantic search for an al ternative vice aircraft and always, on previous occasions, having frequency; I looked in my R.A.A.F. en route chart had the right frequencies in civil aircraft I had flown, I (three months out of date) and to my delight saw made out my fl ight plan, entering "RUT VHF and 3023.5 listed. I began calling Canberra on this fre­ RUT HF'(- in the appropriate spaces, without knowing quency. whether these frequencies were fitted to my aircraft or not. Mistake No. l! When I had finished, I handed my By this time I had reached the zone boundary and plan to the briefing officer. Next to the words "RUT needed a miracle to save face, so dismissing my private VH F" he wrote "118.7 and 121.7", explaining that these thoughts about Canberra Tower's tardiness on 3023.5, I frequencies were now mandatory for aircraft operating switched over and called them on 121.7, their ground into Canberra. I nodded my head wisely and assured him conh·ol frequency. Mistake No. 4! I managed to contact that I had them. Mistake No. 2! The briefing officer Canberra on 121.7 and asked if they were listening on handed me copies of all the relevant Notams, which I 3023.5. To my horror, I was promptly informed that this placed in my "nav" bag with a knowing nod, but with­ frequency had been removed from service more than two out so much as a glance. Mistake No. 3! I was to read months previously! In a small, unconvincing voice I these N otams, very much the wiser, on my way back to asked if I might enter the zone on the ground control Bankstown later in the day. My complacency continued frequency. Their very definite "Negative" was only to assert itself during my pre-flight checks, and I finally what I expected and deserved. I turned on to a recipro­ departed Bankstown still not having verified the fre­ cal heading and set course back to Bankstown. During quencies in the aircraft's V.H.F. equipment. the flight home I took out the disregarded Notaro sheets

Jf Standard Abbreviation fo r "Route Frequencies". and there, sure enough, was the statement that 3023.5

18 AVIATION SAFETY DIGEST SEPTEMBER, 1966 19 had now been removed from Canberra. My embarrass­ the benefit of mysel f and other pilots, so vvhy not ment was complete. use them? *Briefing Rooms provided at Airports are effi ciently The trip, as it turned out, was not entirely wasted. run and the staff always more than helpful, but all Even though I didn't actually get to Canberra, at least this effort and expense is wasted if I don't listen to my experience benefitted, and it forcibly drove home a vvhat the briefi ng offi cer has to say. few points which I think are worth passing on:-

*Before making any future trips I mu st make sure I Familiarity breeds contempt. I thought I knew all my have the correct frequencies, and note those that I communications procedures for cross-country flying have, as well as those that I will need, on my flight pretty well, but my judgment was based on past, not plan. present, airspace utilization. With the increase in the (Swnnnary based on Accident Report issued by Ministry of Aviation, U nited IGngdoni) volume in traffi c, and the growing complexity of the air * Notams and other amendments to issued aero­ traffic control system, near enough obviously isn't even nautical information, are only made available for close, let alone good enough! i\ n Avro 748 was making an ap­ nose undercarriage and bounced two landing load had been taken by the proach to land at Leeds/ Bradford or three times. Both nosewheel tyres nose undercarriage. T he port nose­ COMMENT: Airport at the end of a scheduled burst, the port nosewheel disinte­ wheel had disintegrated and the star­ night flight from London. At the grated, and a piece of the wheel cast­ board was broken. In the nose leg Some readers may be inclined to think that Canberra Tower's t reatment of t he pilot in time, a frontal system was moving ing struck the port propeller and was attachment area, the fuselage skin this case, was a little unreasonable. After all, if he was in communication with the tower, why through the area and the surface Sung through the side of the fuselage was wrinkled and frame and stringers not let him enter the zone? Our contributor has summed up the situation very aptly, but a little wind at the airport was reported as into the forward section of the pas­ distorted. T he nature of the damage further explanation may help to clarify the thoughts of readers who are not familia,r wit h the 150 degrees, 20 knots, gusting to 30 senger cabin, where it came to rest was consistent with a severe upward Canberra Control Zone. knots. on the starboard luggage rack. Direc­ and to starboard loading from the tional control of the aircraft was nose undercarriage. The Aerodrome Approach Control Unit at Canberra is responsib le for providing separa­ From 10 miles south-east of the maintained and it was brought to rest tion and aerodrome operational information for a complex range of aircraft activity including airport, the aircraft was directed by Examination of the nosewheels approximately 500 feet from the up­ military training in both helicopters and fixed wing aircraft, civil training in general a viation rada r to a position for a visual ap­ showed that they had been severely wind end of the runway. No one was overstressed during the landing; there a ircraft, regular public transport aircraft, and general aviation aircraft on local and cross-country proach to runway 15. Turbulence was injured. was no evidence of any pre-accident flights. With the work-load generated by this dive rse volume of air traffi c , faci lities a re simply experienced and the approach was defect. Laboratory checks showed the not available to permit an approach control service to be provided on the surface movement made with a flap setting of 22Y2 At the time of the accident, work wheel material to be metallurgically control freque ncy. Unless an e me rge ncy situation exists therefore, or the fl ight is of an urgent degrees. As the aircraft approached was in progress to extend the runway. and mechanically satisfactory. The medical nature, a clearance to enter the Control Zone cannot be issued to an aircraft that is not the runway, the crew's view was im­ The threshold had been displaced and characteristics of the fracture of the equipped to communicat e on the freque ncies specified in Air Navigatio n Orders, Ae rona utical paired by heavy rain and sleet caus­ the length of runway available for Information Publications a nd Notams. port nosewheel indicated that it had ing glare in the beams of the landing landing was 3,350 feet. T he calcu­ failed under a single application of lamps. Glare from the runway lights lated landing distance required by stress and there was evidence that this reflecting in the wet runway also the aircraft in the existing conditions stress occurred while the tyre was still became dazzling. In gusty, turbulent was 2,775 feet. For technical reasons inSated. Inspection of the nosewheel conditions, the aircraft crossed the the lowest intensity setting of the tyres showed that they had been threshold at about 100 knots, three runway lights available was 10 per severely abraded laterally and pene­ knots above the optimum threshold cent of their full brilliancy. Portable Report That Heavy Landing! trated by the wheel flanges after speed, and as it was about to touch­ angle of approach indicators were in use. Inspection of the runway showed being deHated. The engineers removing the cowls of a Cessna 182 undergoing engine maintenance in an authorised down the wind veered 30 degrees. three separate impact marks which The propellers of the Avro 748, as workshop, found that the firewall and adjacent skin on the underside of the fuselage were extensively T he initial touchdown was moder­ were attributed to the nosewheels of on all Dart engined aircraft, are fitted damaged. ately heavy. W hen the aircraft seemed the aircraft. The first marks com­ with fine pitch stops for both ground to be fi nnly on the runway, the cap­ fine pitch and llight fine pitch. T he A check was made of the operator's aircraft records for the preceding three months but this check, menced 1,430 feet along the runway tain permitted the first officer to select from the displaced threshold; the ground pitch stop is a fixed stop and other enquiries, could not establish how or when the damage had occurred. It was almost certain, never­ ground fi ne pitch, accomplished by which corresponds to a propeller second at 1,645 feet and the third at theless, that the damage was the result of a heavy landing. withdrawing the flight fine pitch stops blade angle of zero degrees; it is pro­ 1,730 feet. of the propellers. As the first officer Had the damage not been detected it could have progressed to the point of causing a serious accident vided for use on the ground when did so, the aircraft became airborne Examination of the aircraft revealed starting the engines, and to ensure - -ALL BECAUSE ONE UNTHINKING PILOT FAILED TO REPORT A HEAVY LANDING. again, then pitched heavily on to the that an abnormal percentage of the maximum windmilling drag for re-

20 AVIATION SAFETY DIGEST SEPTEMBER, 1966 21 tarding the aircraft during the ground lever should only be operated when noscwheels contacted the runway run after landing, or during an aban­ the aircraft is on the ground. The initially, the captain thought the air­ doned take-off. The flight pitch stop landing drill stipulated in the flight craft would stay on the ground and is intended to be engaged at all times manual requires the propeller flight this prompted him to allow the first in flight and prevents the blade angle fine pitch stops to be withdrawn as officer to withdraw the High t fi ne from falling below 18.5 degrees, thus soon as possible after the nosewheel pitch stops. The reason for the air­ preventing excessive windmilling has touched the ground. craft becoming airborne again was drag. When the flight fine pitch stops The first touchdown, which was not fully established, but it is likely are withdrawn, the propeller blades heavier than normal, probably re­ to have been a combination of a wind are free to move to the ground fine sulted from the pilot's impaired visual gust and reaction to oleo leg com­ pitch stops. Withdrawal of the stops reference and the gusting wind con­ pression. When the aircraft left the is controlled by a single lever on the ditions. T he ensuing damage to the ground again the airspeed was too low throttle pedestal. Although it is pos­ aircraft, however, was not attributed fo r elevator control to be effective, sible to withdraw the flight fine pitch to the initial contact with the runway, and, as ground fine pitch was stops in flight, provided the throttles but to the events that followed, caus­ achieved, the ensuing windmilling are closed, t11 is practice is not per­ ing the aircraft to land again heavily drag caused the aircraft to pitch • mitted and the pitch stop vvithdrawal in a nose-down attitude. When the hea vily on to its nosewhecls. Control Lost In l.M.C . A private pilot who had no instru­ then instucted the pilot to turn right found on level ground a mile from ment qualifications departed with two again on to 120 degrees. During this the Austin VOR. T he aircraft had passengers in a Beech Baron on a turn the pilot was also told to descend dived into the ground with great force ANTENNA OBSTRUCTS private flight from Houston, T exas, to, and maintain 2,200 feet. T he with both engines developing power. AD F Sen se Rubber Bungee to El Paso on the Mexican border, a pilot acknowledged, saying he was T here was no evidence of any failure Antenna Cord distance of some 580 nautical miles. descending "very rapidly". The con­ or malfunction having occurred be­ TAIL TRIM MOVEMENT TAIL ASSEMBLY SETTING WITH Defore taking off and afterwards in troller then advised him the aircraft fore impact. An eye witness described i+ TRIM IN NEUTRAL flight, the pilot was advised of "below appeared to be in a tight turn and hearing the sound of a low-flying air­ A Mooney taxied out for take-off at Moorabbin Air­ Wire VMC" weather extending eastwards told him to turn left on to 120 craft, and seeing it emerge from the port, but while at the holding point, the pilot advised Safety . POS ITION Li nk from a cold front that lay across the degrees. There was no response and low cloud and fog, strike the ground he was returning because the e levator trim was unservice­ proposed track about midway. The shortly afterwards all contact with and burst into flames. able. Th e pilot had found that no nose-down trim move­ pilot also received a sigmet which the aircraft was lost. The Austin ment could be obtained. C.A. B., U nited States. reported extremely adverse thunder­ weather at the time was "Ceiling COMMENT: On this aircraft, the A.D.F. sense antenna is attache d storm activity, with tops 25,000 to 200 feet, broken, 1,000 feet overcast, The old, too-often repeat ed story to the top of the fin. In vestigation established that just 35,000 feet, in the vicinity, and ahead visibility two miles, light ram TAIL ASSEMB LY of the non-instrument pilot con­ before the aircraft taxied from the tarmac, the A.D.F. of the front. showers and fog" . SETTING WITH t inu ing into l.M.C. weather, wit h sense a ntenna, had been shortened for tuning purposes TR IM IN NOSE- UP Approaching Austin, approximately The wreckage of the aircraft was loss of cont rol t he inevitable result. by radio maintenance staff. Th e radio e ngineers did not POS ITION 120 nautical miles from H ouston, know that on the Mooney, the elevator trim operates by forty minutes later, the aircraft en­ moving the whole empennage including the fin, and that countered cloud and the pilot was a ny slack in the aerial wire connected to the top of the advised to con tact Austin Approach. HELICOPTER OVERTURNS fin is taken up by a bungee cord in series with the aerial In response to queries, the pilot in­ wire. A wire safety link, installed in parallel with the formed the controller that he was The pilot of a H ughes helicopter, the other skid, and the pilot decided bungee strainer, provides for failure of the bungee (see - fl ying on the autopilot at 3,800 feet making a landing on a beach, de­ to take off again to find a firmer area. TA IL ASSEMBLY diagra m) . cided to touch down where the sand As he tried to do so, the embedded - SETTI NG W ITH in instrument conditions and would was wet, instead of on a dry area, to skid caused the helicopter to heel When the adjustment to the aerial was made, the trim TRIM IN NOSE­ declare an emergency to "get down" avoid blowing loose sand. T he land­ over towards the starboard side. The position was such that there was some slack in the safety DOWN POS ITION rather than continue. He said the air­ ing approach was made into the crosswind, blowing from the port wire. The adjustment to the length of the aerial took up craft was equipped with ILS and he north. At die time a 10-15 knot wind side, accentuated the effect, the main this sla c k and prevente d the fin from pivoting bac k as the was familiar with its use. T he pilot was blowing from the north-west. rotor blades struck the grnund, and trim was wound further towards the nose-down position. was then instructed to turn right from 320 degrees on to a heading of As the aircraft touched down, the the helicopter rolled on to its star­ The fault was corrected by replacing the wire safety 020 degrees. The approach controller landing skid on the starboard side board side. link with another of adequate length. reported radar contact established and sank deeper into the wet sand than C.A.B., U nited States.

22 AVIATION SAFETY DIGEST SEPTEMBER, 1966 23 OVERSEAS ACCIDENTS IN BRIEF • VICTA COLLIDES WITH POWER LINES Fish Spotters Collide 1n Flight

Flying solo over Rotorua, N.Z., the the City Council, the police and the learned from this accident is too pilot of a Victa 100 was making an Chief Flying Instructor of the aero obvious to require elaboration. . While the pilots of two Champion pany. As his aircraft was turning sions, though for different companies. experimental broadcast on V.H.F., his club. When the pilot raised the mat­ Department of Civil Aviation, 7EC aircraft were each engaged in through a westerly heading he heard By common consent all fish spotter commentary being recorded on tape ter with his Chief Flying Instructor Nevv Zealand. spotting fish for their respective com­ a bump and thought he had been hit pilots working in this area use an pany's fishing vessels, the aircraft by a local broadcasting station. Just the following clay however, he was by another aircraft. After the impact altimeter setting of 30.00 inches to collided in the air over Chesapeake after he had described his fli ght at low told in no uncertain terms that no­ his altimeter indicated just under maintain separation. The altimeters Bay, Virginia, on the east coast of the level across the playing fields of a body vvould be permitted to fly below 1, 700 feet. After advising his fishing of both aircraft were found set at MISJUDGEMENT United States. Neither aircraft was Rotorua high school, his commentary the regulation minimum safe height. vessels, he too, returned and landed 30.00 inches but the exact altitude badly damaged and each was able to ended abruptly and, at the same in­ If the pilot wished to fly over the During Low Flying without further incident. Neither of the accident could not be deter­ stant, the electric power supply to the return and land at its base. city, he would have to do so abiding While making a local flight with pilot had seen the other's aircraft im­ mined. Both pilots had failed to city was cut off. At that moment, eye Examination of both aircraft by all offi cial regulation s. The pilot the pilot alone on board, a PA-22 mediately before the collision. maintain surveillance sufficient to witness had seen the air.craft collide showed that the starboard undercar­ made no further mention of low fly­ struck a clump of trees at the edge ensure adequate separation while \Nith a high tension power transmis­ riage fairing, with the tyre and tube, D uring the investigation it was ing, and on the clay of the accident, of a clearing, and crashed. The pilot they were manoeuvring in the same sion line bordering the playing fields on the higher aircraft had been found that the pilots, both of whom informed the duty controller at Roto­ was seriously injured and the air­ limited area. of the school, and crash in scrub damaged by striking the propeller were very experienced, had worked rua that he would be making a local craft substantially damaged. nearby. The pilot was killed and the and the upper port side of the lower this area together on numerous occa- C.A.B., United States. flight of about an hour's duration aircraft destroyed. The purpose of the fl ight was to aircraft's engine cowling. T he fuse­ over the city and its environs. drop maps to a group of Boy Scouts lage underside of the higher aircraft No reference was made to flying low The pilot was a radio announcer in timbered country, 350 feet above had also been damaged as it brushed during this conversation. Approval with the broadcasting station to which sea level. The clearing into which across the upper surface of the lower he had been transmitting his com­ for the pilot to make a fligh t of one the drop was being made is roughly aircraft's starboard wing. T he starboard Wings Fail During Test mentary. He held a student pilot hour was given by a club instructor circular and 600 feet in diameter. The fuel tank fi ller neck had been torn licence and had been flying for less in the usual way and the aircraft clay was fine and clear and there was from the lower aircraft. Flight than two months, his total aeronau­ took-off. Twenty-five minutes later no wind. The pilot of the higher aircraft said tical experience amounting to only the aircraft crashed. The aircraft made four runs across that before the accident, while he was A highly-experienced commercial actually seen the aircraft shed its 27 hours, 11 hours of which was solo the clearing, the first at about 1,000 flying at an indicated altitude of 2,000 time. About 10 days before the acci­ The day was cloudy and the power pilot departed on a local flight in an wings. feet above the ground. T he succeed­ feet assisting his company's vessels to dent, the pilot had mentioned to club lines would have been difficult to see Aeronca, to test the operation of a Investigation established that tl1e ing three runs were flown at pro­ set fishing nets, he noticed two other instructors that he was hoping to from the low-flying aircraft, as they gressively lower levels. On the final fish-spotting aircraft working in the newly-installed carburettor. A few wings had broken off at the spar root make an experimental broadcast from would have been against a background one, the aircraft appeared to dip area, one about 500 feet below him, minutes later the aircraft was seen at attachment points. The main attach­ the air, and that if reception by the of hills. In any case, the pilot's pre­ slightly over the clearing, then struck and the other about 1000 below. about 5,000 feet over the vicinity of ing bolts remained in the fuselage at­ broadcasting station was satisfactory, occupation with handling the micro­ a clump of trees 50 feet high on t.he While he was circling to the left in the airport carrying out what appeared tachment fittings, but the correspond­ he would then like to make another phone and concen trating on his south-west side. The impact swung a 30-degree bank watching the boats ing holes in the wing spars had been flight, cluing which he would describe to be stalls. One witness, who was broadcast would to some extent have the aircraft to the right and it strud< close the fish nets, he felt a bump el ongated and the bolts had pulled his experiences for the benefit of watching the aircraft, said that after precluded his maintaining an effective a large tree 225 feet further on, fell and then saw the other Champion as out through the metal and wood spar listeners to the station's ''breakfast being momentarily distracted he lookout. to the ground and came to rest upside it passed beneath his aircraft. After fittings. Examination of the failed session". To these general proposals looked for it again, and saw that both down. the collision he levelled out and saw parts, including the fly ing wires, the aero club had no particular Eyewitness accounts of the final The pilot said he thought the air­ that the altimeter read 1,900 feet. wings had separated from the fuselage objection. showed that the fail ures were the stages of the flight confirmed the craft had encountered a downdraught After checking that the other aircraft and that it was diving to the ground. result of in-flight positive overloads. was still flying, he advised his com­ T wo clays before the proposed ex­ pilot's description recorded on the but it seemed unlikely that a down­ The fuselage crashed 400 feet from There was no evidence of previous pany of the collision and returned to perimental fli ght, the pilot spoke to tape and the cause of the crash was draught of a sufficiently serious the airport boundary and the wings failure or fatigue. T he accident was only too clear. Responsibility for com­ nature could have existed at the time. his aerodrome to land. the Aerodrome Superintendent at fell to the ground independently, attributed to in-{1.ight overloads ;n­ plying with the regulations rested en­ More probably, the diversion of the The pilot of the lower Champion Rotorua, requesting permission to fly landing some 200 feet away. Wit­ duced by the pilot, which had ex­ low over the city during this flight. tirely on the pilot. He had sought pilot's attention between fl ying his said that before the accident he was nesses said that they heard the engine ceeded the design strength of the He was told that it vvould be neces­ permission to fly low and had been aircraft and dropping the maps, had circling to the left in a 15-degree aircraft structure. sary for him to obtain the consent of refused it, then took it upon himself contributed to the pilot's misjudgment. bank at an indica ted altitude of 1,650 runmng at high power until the the Department of Civil Aviation, to act as he did. The lesson to be Department of T ransport, Canada. feet while spotting fish for his com- moment of impact, but none had C.A.B., United States.

25 24 AVIATION SAFETY DIGEST SEPTEMBER , 1966 19ke-lime-fo THINK: • • Engine Failure? Fuel Exhaustion? • Pilot Incapacitation? What then?

clearly did not involve any systematic changes of head­ ing to either return to his last-known position or to inter­ . . . Simply that the pilot missed his destination on the final 37-nautical-mile leg of an 85-mile cept an obvious landmark such as main western railway cross-country flight and didn't take time to try and establish his position. Instead, he decided to line. The pilot had not sighted the spur railway to land in the first likely looking paddock, to find out where he was. Unfortunately, for the pilot, it Oberon as he expected, seven minutes after crossing wasn't likely enough! the Jenolan Caves road, and this should have alerted who find themselves caught out by bad weather or poor him to the fact that he was off track. Then, when he vi sibility. Instead of diverting a little sooner to an area The flight from Bankstown to Bathurst, N.S.W., was however, proved to be downhill, and although he imme­ failed to sight any section of the main western railway, where better conditions were known to exist, some have part of a solo cross-country navigational exercise to diately applied full braking the aircraft ran for 800 feet and Bathurst finally did not materialise by ET A, this gone on to the point where they have felt their only qualify the pilot for the issue of an unrestricted private and into mounds of earth and soft soil in the lower should have confirmed he was south of track and sug­ alternative was to land at the first possible opportunity. licence. The weather was fine but smoke haze reduced corner of the paddock. The nose wheel dug in, and the gested a turn to intercept the railway- a feature he In these circumstances, even comparative "old hands" visibility to about five miles. The first part of the Bight aircraft somersaulted slowly over on to its back. The could hardly miss. Alternatively, if he was in real doubt, have acted as this pilot did and their undue haste has was uneventful and the aircraft arrived over Katoomba pilot was not hurt and after finding he had landed 23 the pilot could have turned on to a reciprocal heading frequently had similar results-results that could easily on ETA at 0058. The pilot set course for Bathurst, ETA miles south-west of Bathurst, he reported the accident and flown back to his last-known position. H e had more have been avoided with a little forethought and common 0123, and seven minutes later pin-pointed his position to Banl

26 AVIATION SAFETY DIGEST SEPTEMBER , 1966 27 ------:r.-----.=------

Transcript from a recording tape in the Control Tower of a capital city Airport:

RME: Romeo Mike Echo. When we turn on to final, I wonder if you could give us an intermittent wind check? Tower: Romeo Mike Foxtrot-will do. Continue approach and I will give you RME: Romeo Mike Echo is coming up final for Zero Two. frequent checks on final. Tower: Romeo Mike Echo - the wind is picking up now - it is oscillating RME: Romeo Mike Foxtrot. Many thanks. violently through about three zero degrees - zero three zero to zero six Tower: Romeo Mike Foxtrot - the wind is oscillating now between zero five zero zero. One five and up to two ·five knots. and zero niner zero, one zero to two five. Clear to land. Tower: I will give you a further check on short short final. Clear to land. RME: Romeo Mike Foxtrot. RME: Romeo Mike Echo - would zero six be more suitable do you think? Tower: Wind check: Zero five zero to one one zero, one five to two five. Tower: It could be - the wind is changing so rapidly. If you would prefer over- shoot and have a look at zero six. COMMENT:

RME: Roger. Overshooting. Would you light zero six? Notice that two transmissions after addressing occurred and that pilots and controllers alike must Tower: Roger. MMF, ihe tower controller erroneously transposed constantly be on their guard for potentially danger­ the last letter of RME 's callsign and addressed it as ous errors of this sort. No difficulties arose on Tower: Mike Mike Foxtrot - Cross zero six and hold on the taxiway, clear of Romeo Mike Foxtrot. RME's response is a particu­ this occasion but that is not to say that serious both rnnways. larly interesting example of thought transference; confusion and perhaps traffic confliction could not Tower: Mike Mike Foxtrot - Moderate to severe turbulence reported in the instead of correcting the error the aircraft per­ occur in similar circumstances. circuit area. We will see what the 727 has got to say after he arrives. petuated it and acknowledged as Romeo Mike Fox­ trot! From then on until the aircraft shut down on We don't want to "point the bone" too much but RME: Romeo Mike Echo. We'll confirm that- it is severe. the apron all exchanges between ground and air­ it may be significant that an earlier section of this same tape shows that, on one transmission, only t he Tower: Roger. He says it's severe Mike Mike Foxtrot. craft used the wrong identification. No doubt the stress of the existing weather con­ last two letters of a callsign were used. At the RME: Romeo Mike Echo. Wind check? ditions, and t he fact that the other aircraft's risk of labouring the point, we can only repeat Tower: Romeo Mike Echo - Zero six zero, one five, gusting to two five. Wind call sign contained a rythmic similarity to RME's, again that this practice gains nothing a nd can still swinging very rapidly but only through about three zero degrees at helped t o induce this error. But this does not miti­ obviously contribute to the type of error q uoted in the most. gate the fact that a serious error unwittingly the transcript.

28 AVIATION SAFETY DIGEST