Numt er 90 1975 * AUSTRALIAN DEPARTMENT OF TRANSPORT JlY JJl1 J!JJ~

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Number 90 1975 CONTENTS

Libelle Sheds Wings in Flight ...... 2 6 ( Tree Hazards ...... · · I False Alarm - Boeing 707 Over-runs ...... 10 ..... - ~-=­ ~'~ Is Air-Sickness \'our Problem? ...... · 13 Going Around ...... 14 Hansa Fails to Become Airborne ...... 16 Asymmetric Operation - Can You Handle It? ...... 20 Auto-pilot Disengagement •.••...... 26 The Real Thing! ...... · . . . · · · 27 A Moot Point! ...... · · · · · · · · · · · · · · 28

"1 l'ia1io11 Safer1· Digest i.1 prepared in the Air Safety /rt1'estiga1io11 Bra11C'i and puhlished for the Depart111e111 of 7ra11spor1 1hro11gh 1he A11s1rult1w Go1,ernme111 P11hlisl1111g Ser1•1ce m p11r.1ua11a of RegulalttJll 281 of 1'11· ;I ir \ 'av1ga1io11 Reg11la11011s. lr rs d1s1rih111ed frl'e 1~{ drarge Ill A 11stra/11111 /ice11ce holders ( e.\C'ept sr11de111 pilots J, regl\lered a1rcra_/1 u11·ners. a11d cer­ tain otlrer 11ersu1t.1 and orga11isatio111· lral'lllg u vested operatw11al 11111•resl in ,-I 111·1ralian civil t11 •1at1011 .4 •'WIWll Sa/<'11' D1ge.11 1.1 al"o ami!ahle 011 .wh.H'np11011 from 1'1" A u.Hralia11 v1J\'~rtr111e111 P11hl1shi11g Sen•1ce 111 s/101111 011 tire order form helo11. ("'-' a -_J © Co111111011wealf/1 of A u.Hralia 1975 7/re co111e111s o/ tlw p11hlica11011 11101' 1101 he reproduced m ll'lrole or in purl. 1V1tlrour · '"~' wr1 11e11 a111/ror11_1· of tire Depar1111e/1f o_/ Tramporl. Where 111a1erwl 1:i 11rd1ca1ed 10 he f'\- 1ral'fed jrom or based 011 a11or/rer p11bltcatio11. rlre a111/ror11r o_I thl' orig111a1or slwuld he souglrr. Tire viell'.\ expressl!d h_• persons or bod1e1· II' arlicles reproduced 111 tire A viallOll Sa.fetr Digest from othl'r sources arc 1101 11ecessarilv f/wse oj 1he Depar1111el1f

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Edilor: (i Macartlr11r Joh, 4ssistant Ediror- R .J Maclean. Cover and these pages creasea speea ana reaucea crag. a aes1gn pn11osopny wn1cn rendered obsolete mosr Ansett operation to Lord Howe Island. The difficulty of developing a land aerodro~e Design.- .'\. Wintrip a11d P. Gill previous concepts ~nd led. step by step. to the giant swept-wing landplanes that ply at Lord Howe. and the fact that the service provided the island's only regular link with_ A unique style of Australian civ il aviation spanning four decades finally the world's air routes today. the outside world was to keep this operation going long beyond its economic life. came to an end late last year w ith the c losure ofthe Department's Rose Bay Fly­ Pri111ed h1• A11stralia11 Direcl Mail Ptl'. Lid.. 252-266 Mi1c/re/I Road.. But all this was to take time. In the 'meanwhile. the extensive wartime use of rendering it one of the last regular flying boat services in existence. ing Boat Base on Sydney Harbour. Ale.\andria . .V.S. W. the flying boat had provided a low-cost source of equipment for airline operations in But obviously such a situation could not be expected to continue indefinitely. Built originally in the mid-thirties for the historic London-Sydney Empire Air the early post-war years. Thus it was that Rose Bay saw its heyday in this period. and with the long-awaited completion of the island's runway. on 1 Bth September Route. the base was Australia's first truly international airport terminal. At that time. becoming the focal point. not only for the resumed London-Sydney and Tasman Sea last, the time of reckoning for the Rose Bay base had come at last. the future of large flying boats seemed assured - undoubtedly they were the answer routes. but also for numerous loca! flying boat services. Often. at this time. a veritable In outward appearance. the craft using Rose B ~y have changed little since to regular. long range. !rans-oceanic passenger services. and the graceful. luxuriously fleet of four-engined flying boats could be seen riding at anchor in the Bay. "Centauru s·s· arrival in 1936 and our cover photograph, taken shortly before Ansett's appointed. four-engined Empire boats. developed especially by Short Bros. Ltd. for SU BSCRIPTION O R DER Yet slowly. almost imperceptibly at first. progress began to take its toll. Tne Em­ two remaining Sandringhams left for their new home in the Virgin Islands at the end the London-Sydney route. were but the forerunners of flying ships of the future. At ASSISTANT DIRECTOR (SALES AND DIST~IBU TI ON .J pire route to London. already supplemented by Lancastrian landplanes since its of November. captures something of the base's atmosphere throughout its 39 years least that"s what many people thought when the first of the Emi:iir~ boats. Imperial AUSTRALIAN GOVERNMENT PUBLISH ING SERVICE; resumption after the war. was taken over by Oantas·s newly acquired Constellations of operation. P.O. BOX 84, CANBERRA, A.CT. 2600, AUSTRALIA Airways "Centaurus" . arrived at Rose Bay in 1936. and the Tasman flying boat service to New Zealand was supplanted by DC-6s. And Please record one year's subscription (six issues) lo A viatio n Safety Yet within three years. design was to take a drfb11ic t~Y. ~ ifferent turn one by one. for a variety of reasons. most of them economic. the smaller local service Photographs hy courtesy of Peter Ricketts and NeviUe Parnell, Aviation H istorical Society Digest al $2.95 post paid. under the impetus of VVorld War II. FutuJe development was f \ol'f to~e ~ought by in- operators also began to go out of business. Finally only one service remained - the of Australia and Aorhnes of New South Wales. I enclose $2. 95 in payment D (Cheque or money o rder) Please debit my AGPS account 0 Name .. . . ___ ...... _ ...... - ...... · . . · · · · · · · · S ignature . . . __ ...... _ ...... · ... . · · · Address ...... · . · · · · · · · · · · . . . _...... •...... (Please use block letters) q ate ...... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · Remittances should be made payable to 'Collector of Public Moneys - Australian Government Publishing Service'. A few minutes after being released from an aero tow at Kingaroy, Queensland, and while apparently thermalling a short distance from the aerodrome, both wings of a Glasflugel Standard Libelle sailplane separated from the and the aircraft crashed. The pilot was killed.

• SHEDS

magnitude, the wing fai lure could have speeds. - ' been the result. Ano ther distinct Excessive weight, excessive speed, Bottom: Opposite side of starboard wing spar root, showing that locking pin had been fully inserted. possibility, in view of the pilot's heart violent ma noeuvres and severe tur­ The bush. still attached to the severely bent pin, bul ence all have the capacity to place was torn from the forward portion of the forked . . condition, is that he could have tem­ . . ,...... ~~; ~"'-f. po rarily lost conscio usness, allowing loads on the structure greater than port wing spar root. • ' : ~~1:.il!Jl '" I"" page 4 page 5 Throughout the history of agricultural avia­ The first concerns a De Havi ll and trees, and carried out a normal very edge of the river. T he wings and 1 tion in Australia, the dead or defoliated Beaver that was seeding a flooded rice agricultural procedure turn above the were torn off and the tree, rising above the general height of sur­ paddy close to the Niemur River in forest area. T he aircraft then descend­ fuselage plunged through the trees to ed again, levelling out above the ri ce 1 REI~ rounding timber or other obstructions, has south-western New South Wales. The the ground where it burst into flames paddy was rectangula r in shape, with paddy at the normal seeding height, and was destroyed. T he pilot was kill­ proved a particular hazard to low-flying its longer dimension aligned east-west. but did not drop seed. The third ed. agricultural aeroplanes. Though at first At its western end, its boundary lay seeding run from east to west towards sight, the task of avoiding such apparently only 30 metres from the eastern bank the trees, was completed normally and llAZARI»~ obvious obstructions would seem to present of the river. A line of trees bordered once again the aircraft climbed steeply and began a turn on to a reciprocal no difficulty to a normally vigilant this bank and, across the river, on its western side, there was thick forest heading, flying just above the fo rest. A agricultural pilot, the problem is clearly with trees a little over 20 metres in little more than half way around this much more insidious than it appears. For height. turn however, the aircraft climbed over the years, quite a number of pilots have The day was fine, with only a light suddenly to a height about 30 metres fallen victim to this snare, and the fact that wind and, after inspecting the area above the trees. Levelling out of the hard-to-see obstructions of this type are from the air, the pilot landed at the rather tight turn, it then entered a steep descent back towards the rice still a very real hazard, despite all the ex­ agricultural strip from which he was to operate, to load the aircraft and to paddy, apparently in preparation for perience of the years, is only too evident brief the property owner and an the next seeding run into the east. T he second of these two accidents involved a Cessna 180, one of l wo from two comparatively recent fatal employee who were to act as markers Seconds later however, when still agricultural flying accidents. for the seeding operation. The over the far side of the river about 80 which had been engaged to spread superphosphate on a properly in the markers then took up their positions metres short of the paddy's western Central T ablelands of New South a t opposite ends of the paddy, ready boundary, the aircraft struck the up­ Wales. T he terrain consisted of gently for the east-west runs which the pilot per branches of a sparsely foliated undulating open country, with oc­ had arranged t o begin from the tree, extending some six metres above southern side of the paddy. the surrounding timber. T he impact casional patches of ligh t timber. T he The pilot commenced the seeding tore off the st arboard and, weather '!-Vas fine 'a nd calm, with un­ restricted visibility. operation with a run in to the east, ap­ without any apparent reduction in proaching the paddy from over the power, the aircraft continued to des­ forest. As expected, the aircraft then cend, rolling steeply to the left as it crossed the river. Here, 50 metres made its second run in the reciprocal The burnt out wreckage of the Beaver as it came to direction, at the completion of which from the point of first impact, it flew rest on the river bank nearest the rice paddy being the pilot climbed steeply to clear the directly into another large tree on the treated.

page 6 page 7 After flying to the agricultural strip on the property, the pilot made an aerial inspection of the area to be treated in company with a property employee and then began spreading, lifting about 450 kg of superphosphate with each load. The first four flights were completed normally and, after being loaded for the fifth time, the air­ craft took off, heading as before towards a line of widely-spaced gum trees, generally about 12 metres in height, which lay directly across the aircraft's flight path to the spreading area. Shortly afterwards and before the aircraft reached the spreading area, the engine, which had been run­ ning smoothly at high power, was heard to stop abruptly. Simultaneous­ ly there was a loud crack. The aircraft, in apparently normal flight and evidently without taking any evasive action, had flown directly into the top of a dead tree, in line with but nearly The greater height would probably Above and Below: The remains of the Cessna 180 twice as high as the other widely­ also have accentuated the tendency for as it cam e to rest. The upper picture was taken crossed them several times in the to begin that particular spreading run. relationship with the ground, an spaced li ve gum trees. Several stout looking in the direction of impa,ct and portion of the the branches of the higher, sparsely course of his earlier spreading runs, Bu t again, with the upper branches of agricultural pilot tends to become a branches of the dead tree were· sliced wreckage trail can be seen in the foreground. Note had no doubt established what he the dead tree merging effectively into foliated tree, to merge into the the almost complete destruction of the forward good deal more nonchalant than off by the impact before the severely background as seen from the aircraft. section of the fuselage. believed was a safe height at which to the non-contrasting background of the others both in his attitude to obstruc­ damaged aircraft dived almost ver­ As well as this, the pilot, having fly to a nd from the treatment area. In surrounding paddocks and hills, it tions, as well as in his ability to see and tically to the ground. The pilot was all probability however, this height sighted the marker as a result of the seems that the pilot either did not see avoid them. Yet while this is an entire­ killed instantly. additional height gained, might have was based on his assessment of the it at all, or at least was not aware of its ly natural and e ve n desirable easy-to-see line of live gum trees with proximity to his aircraft until too late characteristic in a capable a nd confi­ * * * * been concentrating on that position as he aligned the aircraft for the next run, abundant foli age cover, and it seems to avoid it. dent agricultural pilot, there surely In neither of these cases does it in an effort not to lose sight of the likely that he might not have noticed * * * * must be a point beyond which it is un ­ the larger dead tree at any time. Once T he message of these two tragically wise even for the most able to go. T h is seem that the pilot sighted the tree marker again. In these circum~tance~ , unnecessary accidents speaks for branches obstructing the flight path in it seems that the pilot could quite easi­ having reached the height that he is especially. so when the pilot, as well believed was safe during the fatal run itself. As in all other types of flying, time to take evading action. In bo~h ly have failed to notice the obstructing as flying the aircraft safely, has to give there are surely no prizes for cutting cases too, the tree branches struck by branches of the tree below his aircraft to the spreading area, the pilot might some of his concentration to the task have transferred his attention to this things fine in agricultural operations. the aircraft extended above the general in time to take any avoiding action. Opp osite Page - of accurately positioning his spreading But perhaps by its very nature, flying height of the other nearby trees. As The mechanics of the accident to the Top: A erial view of area in w hich accident to area further ahead, perhaps concen­ pattern, or otherwise preparing his Cessna occurred, showing final flight path. constantly with almost an intimate well in one case the tree was sparsely Cessna 180 appear to be a little trating on the point where he intended aircraft, perhaps to the detriment of foli~ted, and in the other dead, render­ different. The pilot knew that the line fully maintaining the sharp lookout Bottom: The dead tree struck by the aircraf t. The ing the branches much mor~ diffic~lt of gum trees lay across his flight path that is so important when flying close uppermost branches were broken off by the im­ to the ground. to see. Flights conducted dunng the In­ to the treatment area and, having pact. vestigations of these accidents to The penalties for error in assessing simulate the flight paths followed by where this danger point should lie are the aircraft in vol ved, showed that, heavy indeed, as is all too evident from from the line of flight, the trees struck the examples quoted. For this reason, tended to merge in each case into the a realistic 'margin for error' in any background, and become a~most i.n­ operation is surely no more than very visible as a n obstruction until the air­ sound airmanship - a quality that no craft was almost upon it. pilot wou ld ever wish to deny. In the case of the Beaver accident, it was ev ident the operation was in any case a marginal one, with the trees on the river ba nk located so close to the boundary of the rice paddy. The f~ct that on the pilot's third run, the a!f­ craft dropped no seed after turning over the trees, and then, during the next turn over the trees, suddenly climbed some 30 metres, suggests that the pilot was having difficulty sighting the marker at that end of the paddy. The gain in height possibly solved this problem, but it also meant that a con­ s ide ra bly st eeper descent was necessary to begin the seeding run. page 8 page 9 - fALSI ==~ALARM During the subsequent investiga­ take-off. The condition of the locking count the use of reverse thrust and that tion, the co-pilot's sliding window, mechanism of the window was such the runway on wh ich they were taking which bad sprung open during the that, to all outward appearances, the off was more than 4 420 metres long. take-off, was examined. It was found window was closed and locked. In fact The aircraft should therefore have BOllNG707 that the roll pin, which secures the however, the locking mechanism was been able to come to a stop from VI, window handle to its shaft, was out of adjustment and as a result, the -with at least 940 metres of runway withdrawn about seven millimetres. locking bolt was not fully in place. remaining. In actual fact, the sudden The trigger lock bolt was worn, and Roughness and undulations in the noise of the opening window occurred OVER·RUNS the window adjusting rod shortened by surface of runway I 3R , which had ac­ three seconds after the VI call, by one full turn. As well, there was ex­ tually been discussed by the crew while which time the aircraft had At J ohn F. Kennedy International cessive play in the window handle they were taxi-ing to the runway, were accelerated to 154 knots. Even so, with Airpor t, New York, th e crew of a mechanism. The window was checked considered to have been a factor in the all brakes operating, it theoretically Y ugoslavian-registered Boeing 707 fo r operation and it was found that a opening of the window during the should have stopped 760 metres before were preparing lo depart on a direct force of 22 to 27 kg was required to take-off. T he roughness of the runway the end of the runway. T he captain's night to Rijeka Airport, Y ugoslavia. lock the window, as against the nor­ would have been transmitted to the action in abandoning the take-off was The aircraft was loaded to its max­ mal force of about 20 kg. The spring­ airframe while the aircraft was thus a reasonable one in the ctr­ imum structural weight of 141 520 kg loaded trigger in the handle hung in a accelerating, causing the fuselage to cumstances. and the reference speeds for take-off mid-travel position and the associated nex. With the window locking pin only T he malfunction present in the were calculated to be VI 150 knots, trigger lock bolt did not fully engage partially engaged, this could have been braking system would not have been V R 160 knots, and Y2 170 knots. the lock plate hole. Jn this condition, sufficient to disengage the lock com­ evident in the course of a pre-night in­ When the a ircraft taxied for depar­ though the window appeared to be in a pletely and allow outside air pressure spection. Indeed from all outward in ­ ture from the terminal, runway 22R , closed and locked position, any to force the window open. Had the air­ dications, the maintenance represen­ 3 460 metres long, was in use but as pressure applied to the handle would craft been pressurised at the time, the tative as well as the crew, could only the length which the aircraft required disengage the trigger lock bolt, enabl­ positive pressure inside might have have assumed that the brakes were not fo r take-off was on the li m it fo r this ing the window to open. held the window in the closed position. worn below safe limits and were runway, the crew requested the use of Examination of the aircraft's brak­ Also, because the pressure differential operating normally. There was no the airport's 4 442 metre runway 13 R. ing system showed that the numbers increases as soon as the aircraft leaves maintenance requirement or This was granted and after it had tax­ two, three and fo ur front and rear the ground and the window is a plug­ procedure by which the entire braking ied into position, the aircraft was brakes had been subjected to extreme type installation, it is probable that the system was regularly checked, and cleared for take-off. internal heat. The disc lugs for these co-pilot could have closed the window only in the case of an en tire under­ As the aircraft accelerated, the co­ brakes had been sheared, and pieces of in flight. However, even before the co­ carriage change, would there have p il ot called '80 knots' then, 25 seconds the lugs were found in the wheel slots. pilot had called that the window was been a functional check of the sort later, VI. T hree seconds afterwards A number of the brake return springs open, the captain had initiated action necessary to reveal the malfunction there was a sudden loud noise in the were also missing, several of which to abandon take-off and the problem experienced in this accident. Normal cockpit similar to an explosion. The were fo und scattered over the last 300 thus became one of stopping the air­ landing procedures preclude the use of captain immediately abandoned the metres of the runway. It was also craft within the confines of the brakes al speeds above 80 knots and, take-off, deployed the speed brakes, fou nd that, because of a defective Y-3 runway. when the brakes are applied in normal relay in the port a nti-skid system, the selected reverse th rust, applied I 00 Pilots are keenly aware of the circumstances, they are used only to percent N 1 on all fo ur engines, and number one front and rear brakes possibility of an explosive device being slow the aircraft to turn off the then applied the wheel brakes. As the were incapable of being energised placed on board their aircraft. In addi­ runway. Under these conditions, it aircraft began to decelerate, th e co­ above a speed of 20 knots. As a result, tion, immediate action to abandon a seems doubtful that a pilot could p il ot saw the starboard-side sliding no matter how much pressure was take-off is a natural reaction to a detect the difference between six-wh eel window had blown open and he called applied to the brake pedals, the sudden, unexpected, loud noise. A pilot braking and eight-wheel braking. In 'window open'. Nearing the end of the number one front and rear brakes in this situation nor mally has no way actual fact this difference might only ru nway, the aircraft began a gradual remained in a released condition. of immedia.tely assessing what has become evident when a maximum turn to starboard and, a fter using the Because of the in tense heat generated happened to his aircraft, or whether or braking effort was made, such as dur­ en tire length, it over-ran the right side by the brakes, the fu sible plugs in the not control will be affected. For these ing an abandoned lake-off or a landing of the paved surface, crashed through numbers two, th ree and four front and reasons, the pilot's decision in this on a short runway without using a steel blast fence, and finally came to rear wheels had melted, allowing the case to stop his aircraft on the ground, reverse thrust. At the time the captain rest with the upper section of the port tyres to denate. However, there was rather than to continue with the take­ abandoned the take-off, the crew did wing engulfed in fl a mes. T he eleven evidence to indicate that when the air­ off, is understandable. not believe an emergency situation ex­ members of the crew and all 175 craft came to rest, the tyres were in­ From their performance charts, the isted. Rather they knew that the passengers evacua ted the a ircraft tact and innated. crew knew that the aircraft should runway was more than 940 metres without major inju ry. The fire was * * * * have been able to accelerate to a VI longer than that required for an soon extinguished by the airport The o pening of the co-pilot's sliding speed of 150 knots and stop in 3 480 accelerate-stop in this particular take­ emergency equipment, but the aircraft window was the initiating factor in the metres. The crew also knew that this off. sustained severe damage. captain's decision to abandon the stopping distance did not take into ac- Altogether several factors combined page 1 1 I IS AH~ S~CKNESS YOUR PROBLEM?

Top: View of starboard side of Boeing 707 cockpit showing co-pilot's sliding window and spring load­ ed trigger. Almost everyone, pilots as well as earth-bound mortals, have Trade name A ctive ingredient at one ti me or another experienced some fo rm of motion Inset Diagram: Exploded view of trigger sickness. Whether it be during travel by ship, train, aeroplane Ancolan Antihistamine mechanism. or motor car, or merely as a result of outrageous physical Andramin An tih istam i ne treatment at the hands of some mechanical monstrosity in an Avomi ne Antihistamine and hyoscine amusement park, the sym ptoms are typical. There is first of all Calms Hyoscine a gradual onset of headache, a general feeling of being unwell, Decadol Antihistamine a cold sweat, and nausea which culminates ultimately in Dramamine Antihistamine vomiting if the motion causing the sickness continues. Once Kwells Hyoscine vomiting occurs however, or the motion ceases, there is usually Marzine Antihistamine an immediate improvement in the sufferer. Perazil A ntih is ta mine Motion sickness in flight, generally described as air sickness, Plassids Hyoscine results from disturbances to the inner ear, brought about by Prosamine Antihistamine the accelerations of flight, especially in turbulent air. For this Sea-legs Antihistamine 4 reason, passengers travelling in smaller aircraft are generally Travacalm Antihistamine and hyoscine likely to feel the effects of air sickness more than those in large Travamine Antihistamine R.H. ASSEMBLY SHOWN aircraft with a more stable flight regime. Travel Tabs Antihistamine Experience shows that pilots handling the controls of an air­ Travs Antihistamine and hyoscine craft are not often affected by air sickness bu t, unless they As can be seen from this list, all these preparations are either belong to that happy minority who are seemingly endowed antihistamines or hyoscine compounds. In some cases they are in this case to prevent the crew from third sign ificant factor was that only Probable cause with a 'cast iron constitution', they can be just as vulnerable as slopping the aircraft within the con­ six of the eight brakes were operating a mixture of both. Hyoscine may resu lt in drying of the mouth, anyone else if they are flying as a passenger. but if taken in the correct dose, rarely causes side effects. It is fines of the runway. The first was that and that during the rejected take-off, The National Transportation Safety Is there anything a person can do when he feels all is not well the take-off was abandoned at a speed the effectiveness of the operative probably the best air sickness remedy availa?le. An tihistamine Board determined that the probable in flight and that he might be air sick? Keeping the head steady products, on the other hand, can produce side effects such as four knots above VI. This excess brakes deteriorated and they were sub­ cause of this accident was the un­ on one plane and directing cold air from a cabin vent on to the speed alone produced a 2 10 metre in­ sequently destroyed. The deterioration drowsiness slowness of reaction, and disorientation, but these known degraded capability of the fo rehead can often help avert the worst. But it is wise to keep are not us~ally of seri ous consequence fo r persons fly ing as crease in the stopping distance over occurred because the energy­ heavily loaded aircraft's braking an air sick container handy - just in case! that required from VI speed. Another absorption capacity of the six brakes system, which precluded stopping the There are many remedies for air sickness on the market passengers. . . factor was that the transition segment was exceeded during the captain's Pilots who are inclined to suffer from air sick ness should aircraft within the runway distance which are entirely acceptable for passengers. Many however, drink an adequate amount of fluid before they fly, at the same of the rejected take-off was more than attempt to stop the aircraft on the available. The reduced braking have decided contra-indications for pilots, because of their side 300 metres longer than allowed by the runway. The total energy required to time avoid eating fried or greasy food. And it is a useful exer­ capability resulted from a malfunc­ effects. And unfortunately none sound quite so interesting as cise, when not intending to fly, to test one'.s reaction to one. of accelerate-stop criteria. This might stop the ai rcraft was 53.4 million new­ tioning V-3 relay in the left anti-skid one prescribed for sea sickness many years ago. This was a ·have been the result of either longer ton metres for each of the six brakes, the proprietary air sickness remedies. If it produces s1d.e control shield of the aircraft's braking soup made from horseradish sauce and rice, and seasoned with effects another should be tried in an effort to fmd one that 1s transition times, or the use of less than wh ich was greater than the maximum system, which rendered two of the red herrings and sardines, which the sufferer was to take with maximum braking during the transi­ energy level of 52.6 million newton compa,tible with flying . The doseage instructions should of eight wheel brakes ineffective. A champagne! Other recommendations of yesteryear which course be followed carefully. If necessary the pilot's doctor, or tion period. Both these possibilities m et r es the brakes had been sound like that of an explosion in the might or might not appeal to air-minded travellers today were cou ld be attributed to the fact that the demonstrated to be capable of absor­ aviation medical exam iner should be consulted. cockpit during the take-off roll caused 'tight clothing around the abdomen', 'the prone position', and But even if the problem seems to be defeated, keeping an air crew did not believe there would be bing. the captain to reject the take-off. 'iced champagne'. But lest these should prove unsatisfactory, a any problem in stopping the aircraft in sickness bag (preferably with a good seal!) near at hand when ~~: - ~f;< few of today's proprietary motion sickness remedies are set out the length of runway remaining. The * * * * flying, is good insurance. Charts, or a passenger's new ha_t can in the follow ing table. Most of them do not require a prescri p­ be an expensive substitute! -:"- -"'\\'("' page 12 ti on: page 13 W llY l)fl ):\''.I Ill ( ,( l IH JI '-1>:

11 ...•Ii '"',, d11 " h•lll •II'. ,•11• ~•11110 Ii lh,,.-\ ,,.,,1, .,,,.. , "'IS • • '\l'\• tl11 · ~ .1, .1... t.

Something the Digest reminds its readers about from time to time - to wit these two safety posters published six years apart. But a Jot ofpilots don't seem to get the message and the results usually speak for themselves -

at least the few examples depicted here do so eloquently enough! So don't mind when you have to go around. As we said, even the best pilots do it! Which category are you in?

page 14 page 15 mal rotation speed in the usual dis­ tance. Rotatio~ did not take place however, and the aircraft did not . become airborne. The s urviving passenger saw the first officer's hand holding the thrust levers fully open and wondered why the aircraft did not take­ off. Then he saw a gesture from the captain indicating that the take-off should be abandoned and the first of­ ficer immediately closed the levers. Observers on the aerodrome heard the engine noise die down approximately 300 metres from the end of the runway and subsequently, brake marks· were found commencing in the same are·a. The aircraft left the end of the runway at high speed, in a level attitude, with its nosewheel and main wheels still in contact with the ground. The first collision occurred when the starboard struck and severed a post supporting one of the runway ap­ proach lights. The aircraft continued, colliding with and badly distorting the double-track railway line bordering the airfield. The nosewheel was broken off and structural damage w11s done to the underside of the fuselage. Almost im­ mediately beyond the railway line, the aircraft broke through a wall and collided with a row of single storey masonry chalets in the adjacent holiday camp, demolishing six of ·them and set­ ting them on fire. Both wings were broken off, spilling fuel over the area, but the main part of the aircraft con­ tinued on, sustaining forther damage as ' The accident The other two passengers did not it did so. The wreckage finally came to The aircraft was one of a number of the arrive at the appointed time and the rest against a second row of chalets, same type operating a twice-weekly APU was shut down while the where it caught fire and was destroyed. charter service between the Federal passengers and crew waited in the air­ HANSA fAllS TD BECOME AIRBORNE Republic of and the United craft. About 1630 hours, word was Condemed from report issued by Departmelll of Trade and Industry, United Kingdom Kingdom. On the day of the accident, received that the two extra passengers Investigation After accelerating normally for take-off from Blackpool, England, a the aircraft arrived at Blackpool from were not coming. This meant that extra · Munich just after 0900 hours. It was on fuel could be accommodated, and a new Examination of the wreckage showed German-registered HFB 320 Hansa jet failed to rotate and continued at the ground at Blackpool throughout the flight plan direct to Munich was that the aircraft had been intact when it high speed down the runway. The take-off was abandoned, but the air­ . day and, for most of the time, the crew prepared and filed by the first officer, struck the railway line, and the flying remained with it. while the captain carried out the pre­ controls had been in the neutral posi­ craft failed to stop, over-ran the aerodrome boundary and the railway At 1520 hours, six of the eight flight check. Subsequently, the captain tion. The cockpit, which had been passengers to be carried on the return started the APU and, according to the twisted to the -right and almost in­ line that bordered it, and crashed into the buildings of an adjoining holi­ flight to Germany arrived at Blackpool passenger who survived the accident, verted, had been badly affected by fire, day camp. The two pilots and five of the six passengers were killed; the airport and, as it was raining, sat in the indicated , that the first officer should but it was established that the control ail'craft, the of fl y the aircraft in command under on the captain's side had been aircraft was destroyed by impact forces and the fire that followed. The which was running. A flight plan was supervision from the right.hand seat. broken off in an upwards and forward surviving passenger, who was thrown out of the wreckage, was seriously prepared for Munich via Rotterdam The aircraft taxied out, lined up and direction. The gust lock attachment injured. and filed at 1530 hours. began its take-off run, reaching its nor- spigot on the forward yoke of the cap- page 17 page 16 tain's control assembly was found to tended. The crash switch had been referred specifically to proving the significance. Once a malfunction had be bent in a manner consistent with o perated. freedom of the fl ying controls was in become apparent to the pilot it is the elevator gust lock having the ' Before Starting Engines' check. reasonable to assume that he would been in position at the time the aircraft Analysis This could easily have been overlook­ have abandoned the take-off prompt­ collided with the railway line. There ed, had the captain's check been in­ ly. However the effect of the elevator was no impact mark or other damage The evidence indicated that the pilots terrupted. In this context, it might be gust lock in the control system would to account for the bend in this spigot. were not incapacitated in any way dur­ pertinent that the departure was not necessarily have been apparent un­ The control assembly on the first of­ ing the attempted take-off, and no delayed, and a new flight plan made til rotation speed was reached and it is ficer's side had broken up whilst in the evidence of defect or malfunction was out, when two of the prospective likely that some confusion as to why neutral position, and the absence of fou nd during the investigation that passengers did not arrive. It is con­ impact marks on either set of control the controls were not operating might could account for the failure to rotate. sidered unlikely that the first officer, assembly stops indicated that they had have delayed corrective action by the However, the mode of break-up of the on his return from filing the flight not been ' hammered' at any time"dur­ pilot. T he take-off was abandoned cockpit elevator controls indicated plan, would have duplicated the while the aircraft was still on the ing the break up. that they were in a neutral position ' Before Starting Engines' check runway and the deceleration initiall y The aircraft's elevator controls are when the firs t impact occurred. The already carried out by the captain. achieved on the concrete surface might manually operated and of conven­ results of calculations, and the observ­ T he elevator portion of the gust lock tional pattern. Locking either set of have given the pilots the impression ed perfo rmance of the aircraft, also in­ was inconspicuous when installed and cockpit controls locks the entire that the action thus far taken was dicated that the elevator control sur­ did not interfere with access to the system. The gust lock system provides enough to stop th e aircraft within the faces were in the neutral position seats or the operation of the aircraft in fo r lockin g the controls in the cockpit confines of the aerodrome. Perhaps throughout the take-off run. The lack any way other than the locking of the and consists of a pa ir of webbing when the aircraft co ntinued on to the of impact marks or damage to any of elevators. There was no requirement, stra ps, a 'T' shaped meta l fitting, a nd grass overrun it was no[ immediately the control stops on either the cap­ in the ' Before Take-off Check', to ex­ a light alloy tubular rod which are nor­ apparent that the deceleration was tain's or co-pilot's controls, indicated ercise the flight contro ls and, as the ma lly co nnected together by cord. now considerably reduced and the that they were not forcibly struck at There· is no interconnection between pilots would probably have been oc­ brakes alone wou ld not suffice. But any time in the accident sequence. the gust locks and the thrust levers, cupied with copying their clearance whatever the reason fo r the delay, the Damage to these stops would certainly a nd it is possible to obtain take-off and preparing the aircraft for take-off braking parachute was not unlatched have resulted had the cockpit controls power with the locks in pl ace. When in while taxi-ing out, it is probable that and the undercarriage not selected up, use, the webbing stra ps a re fastened been free to move. the flight controls were not checked until it was too late for them to effec­ over the control wheel horns to The gust lock attachment spigot on before the start of the take-off run. On tively reduce the speed of impact. provide protection, the the forward yoke of the captain's con­ public transport aircraft it is common Cause is held by inserting the 'T' shaped trol column was fo und to be distorted practice for the freedom of the flying in a way indicating that it had been in controls to be checked after the T he accident was the resu lt ofa fa ilure metal fitting through a hole in the lo unstick at the appropriate speed, cockpit floor, into a matching hole in position when the accident occurred. engines have been started, during the VIEWA T here was no other related impact 'Before Take-off Check'. T his is most probably because the elevator the rudder mechanism , and the gust lock was still in position. T he e levators are locked by a light a ll oy damage or apparent reason to account specifically · to guard against the for the bending o f this spigot. possibil ity that one of the control lake-off was abandoned at too high a rod located on two spigots on opposite speed for the aircraft to be brought to Although the gust locks should have locks might sti ll be engaged or that corners of the pantographic elevator rest before colliding with obstructions. control assembly. The manufacturer been attached to one another and movement of the controls is inhibited specified that the gust locks should should therefore have been stowed in some other way. a l wa ys be fast e n ed t og e th e r. forward, but fouling of the aircraft 1. Pin. together after removal prior to take­ In the absence of any interconnec­ Notwithsta nding these instructions structure by the lock strut prevents 2. Aileron gust strap. off, only the rudder locking part of the tion between the gust locks and the they were sometimes separated for a ny degree of rearward movement. 3. Length adjustment device. gust lock assembly was found during thrust levers in H F B 320 aircraft at ease of installation, and . they were T he only remnant of the gust lock 4. Ruddf!r gust lock pin. the search of the wreckage. T he the time of the accident, it was possi­ reported to have been sepa rated on the eq ui pment found in the wreckage was 5. Bel/crank. absence of a split ring on the part ble to obtain full power from the 6. A ileron gust lock strap. aircraft invo lved in the accident. When the steel, T-handled, rudder locking found indicated that the components engines with the lock in place, and the 7. A ngular bracket. installed as the m anu facturer intend­ pin. It was noted that the steel split had not been fastened together, design and performance of the aircraft 8. Hook. despite the maker's recommendation is such that, with the elevator gust lock ed, the complete gust lock system ring, by which the aileron straps a nd 9. Forward yoke. that they should be. in position, the aircraft is incapable of hinders access to the pilot's seat suf­ e levator gust lock are normally at­ 10. Elevator gust lock strut fi cie'ntly to provide a safegua rd. tached to the rudder locking pin, was 11. A ft yoke. T he captain was known to make unsticking. Later H F B 320 aircraft However this hindrance is provided by missing. 12. Steel split ring. frequent use of the gust locks and, have been modified so that is is no the aileron straps and it is lost when Other evidence which came to light since the aircraft had been standing all longer possible to obtain take-off the elevator gust lock, disconnected during the wreckage examination day, it is most probable that they were power from the engines with any of the from the rest of the apparatus, is in­ showed that the fl aps were at the take­ in position on this occasion. Accor­ gust locks engaged. stalled on its own. It was noted that if off setting and the speed brakes were ding to the ev idence of the survivor, T he considerable period between the elevator gust lock is dislodged out. The was selected up the pre-flight check was carried out by the aircraft attaining rotation speed from its bottom spigot only, the con­ and the braking parachute was un­ the captain. The only item on the and the subsequent decision to aban­ trol column can be m oved fully latched with only its drogue chute ex- check list carried in the aircraft that d on the take-off is of some page 18 page 19 j neared the extension of the runway ed, after the Cherokee had touched was not extended. Applying full power centreline, was still high on final ap­ down, that it seemed to be taking an on the starboard engine to go around, proach. Continuing his single-engine unusually long t ime to leave the the pilot quickly glanced at the under­ approach at about 104 knots with the ground again. He transmitted a call carriage selector and saw it was still in fl aps lowered 25 degrees, the pilot of for the Cherokee to vacate the runway the UP position. He selected the flaps the 411 became increasingly concern- and, when the 411 was only a short up from 25 degrees, let the aircraft sw­ distance from the runway threshold ing slightly to port to avoid the and at a height of about 50 feet, the Cherokee climbing out ahead, and other aircraft began to go around. attempted to carry out a missed ap­ Seeing that he now had sufficient proach. clearance behind the Cherokee to con­ By this time, the speed had dropped tinue with the landing, the pilot of the lo 98-100 knots, and looking out, the 41 I closed the on the star­ pilot saw that he was now lower than board engine. the top of the nearby wi ndsock. * * * * Although the Cessna 411 's best single­ Meanwhile, the pilot of a Cessna engine angle of climb speed is 100 150 at the holding point had called knots, the pi lot attempted to achieve ready and had been instructed to hold the best rate of climb speed of 104 position until the 411 had passed. As knots and, as the aircraft did not seem the twin crossed the threshold, he to be accelerating, he went to re-start noticed that one engine was feathered, the port engine. But thou.gh the but then realised the undercarriage propeller turned over on the starter, was still retracted. Picking up the the engine would not fire. During his microphone he transmitted a call that starting attempts, the speed still had •t., the landing aircraft 'doesn't have any not increased above roo knots and wheels down'. realising that, unless the port engine you handle • • As soon as the pilot of the 4 11 had was operating, he would be unable to closed the throttle, the undercarriage clear the rising ground beyond the end can warning horn had sounded. Almost of the runway, the pi lot decided his The condition of the Cessna 41 T's propellers tell simultaneously, he heard the radio only course of action was to land on their own story better than any words. transmission that the undercarriage the grass. Closing both , he

At Jandakot in Western Australia, the to climb away, he reduced power to shut down, he completed a landing to pilot of a Cessna 41 I had planned to zero thrust on the po rt e ng ine, a full stop. Planning to do only one conduct some asymmetric circuit re tracted the unde rcarriag e a nd more circuit to finish the exercise, he training as refresher fl ying in prepa ra­ stabilised the speed at 104 knots, the then re-started the starboard engine ti on fo r an instrument rating renewal aircraft's best single-engine rate of a nd took off again. On the downwind test. Intending lo do an hour's circuits climb speed. At a later stage in the cir­ leg wit h the u ndercarriage still and la ndings, he had arranged with air cuit, he re-introduced power on the lowered, he fea th ered the port traffic control to do his practice during port engine and made a norma l two­ propeller and, after raising the under­ lunch time, when it was expected that engine circuit a nd approach which he carriage, he set climb power on the other aerodrome traffic would be continued down to a height of 100 feet. starboard engine, reducing this a short light. H e the n again carried out a n time later to about 65 per cent to main­ overshoot, this time reducing power tain circuit height and airspeed. About midday the pilot took off on on th e sta rboard engine to the zero A C herokee 140 was ahead of the his first circuit. At about 100 feet, thrust setting. As the aircraft climbed 411 in the circuit and the pilot, hearing a fter retracting the undercarriage, he away on each of these missed ap­ the C herokee report on turning base throttled back the starboard engine to proaches, it passed over rising terrain that it would be making a touch and zero thrust and completed th e circui t beyond the fa r bounda ry of the go landing, waited until the Cherokee and landing with the starboard engine aerodrome and the pilot saw that the was on fi nal appoac.h before turning a t this setting. After taking off again, a ircraft seemed to be clearing this on to base leg himself. He then ex­ with both engines operating, the pilot higher ground by only a bout 50 feet. perienced difficu lty in keeping the made a normal circui t a nd, when he During the nex t circuit, the pil ot Cherokee in view wh ile on base, and had descended to a bout 100 feet late feathered the starboard propeller and, gave his whole concentration to his ef­ on fi nal approach, carried out a prac­ after advising the tower he would be fo rts to maintain separation behind tice overshoot. As the aircraft began ma king an approach with one engine this a ircraft which, as the Cessna 4 11 page 20 During their initial twin or multi­ Yaw Thus it follows that, during a flat engine conversion training, pilots nor­ Yaw is the angular change of aircraft turn using rudder alone, the aircraft mally receive instruction in the basic head ing from a specified datum will yaw in one direction and sideslip theory of fl ight with asymmetric heading. An aircraft which has com­ in the opposite direction. power. They learn the meaning of such pleted a 360 degree turn has yawed Steady asymmetric flight terms as minimum control speed, through 360 degrees. To show the differences between the ta ke-off safety speed, and accelerate­ techniques that may be used to main­ stop performance, as well as the Sideslip tain steady asymmetric flight, we will techniques and important reference Sideslip is the relationship between the consider two cases: speeds ap"plicable to their particular aircraft heading and the direction of • wings level; and a ircraft. They also learn, and have the airflow approaching the aircraft. It • small bank angles. demonstrated to them, that when a may be expressed as an angle ({3) or a Although a third procedure, using light, twin-engine aircraft is flown on lateral velocity (v) - see Figure I. zero rudder deflection could be one engine, the climb performance remaining is not simply equal to half that available with both engines .. v - I LATERAL VELOCITY operating, but is commonly as low as 20 percent or less. Under conditions of I high temperature and aerodrome elevation, this figure niay be even AIRFLOW I lower. If an engine is lost at a critical i stage during take-off, not only may the aircraft be incapable of main­ I taining height in the take-off con­ I figuration, but it may be unable to accelerate from the lift-off speed to a I safe climbing speed without descen­ ding. ~

While most pilots are aware of the selected the undercarriage and flaps events leading up to it contained a The Cessna 41 1 aircraf t as it came to rest looking down, turned off the ignition and number of other object lessons in a ir­ in the direction of flight. Impact and slide marks are magnitude of this performance loss battery mas te r s wi t ches, and manship. [n approaching too close clearly discernible in the foreground. and realise it is not unusual for this manoeuvred the aircraft to a clear behind the Cherokee 140, the pilot class of aircraft, many do not ap­ area beside the runway. The aircraft allowed his a ttention to be diverted to preciate the reasons for adopting a touched down with the undercarriage the extent that he omitted to carry out particular ha ndling technique for one only partly extended and was exten­ his pre-landing cockpit checks. As aircraft type and a different technique sively damaged as it slid to a stop. The well, he persisted with the approach to for another. In fact, in order to pilot was not injured, and left the air­ a very low height and well beyond the achieve even the minimum level of craft immediately it came to rest. stage where he could be certain that performance available with one engine the situation could be recovered if the inoperative, it is imperative that the * * * * preceding aircraft failed to clear the pilot adopt the correct technique for runway in time. And, perhaps most the particular type. Conversely, the It was learned during the subse­ important of all, in continuing his use of the wrong technique can mean quent investigation that the pilot had single-engine approach to a height as an even greater loss of performance never undergone formal twin-engine low as 50 feet, al a slow speed with and, in extreme cases, loss of control. endorsement training. He was ex­ flaps extended and with rising terrain The following discussion briefly perienced on single-engine types and ahead, he placed the aircraft in a posi­ reviews some of the less well un­ had taken the opportuni ty from time tion where he had virtually no chance de rstood t heoret ical aspects of to time to receive dua l training on of ca rry i ng out a succes·sfu l asymmetric flight a nd distinguishes twi n-engine aircraft, but this had been asymmetric missed approach. His ac­ those areas where significant handling spasmodic and conducted over an ex­ tion in attempting to unfeather the differences between aircraft types may tended period. port propeller only served to increase be encountered. Although the basic cause of the ac­ the drag of the aircraft even further at * * * * cident was attributed to the pilot's a critical stage, and his decision to put The first requirement is to clearly omission in neglecting to lower the un­ the aircraft on the ground was wise in understand the normally accepted fig.1. SIDESLIP dercarriage, the ci rcumstances and the circumstances. difference between yaw a nd sideslip. page 22 page 23 described, this method 1s impractical tion indicator however, would show In this case the slip ball will not be as it requires both large bank angles the sideslip angle present. in the centre, for though the aircraft is and large sideslip angles to achieve In this situation, the aircraft's direc­ not sideslipping, it is flying in a steady flight. tional stability would normally cause straight path with a small bank angle. it to yaw into the airflow and reduce Any attempt to centre the slip ball Wings-level asymmetric flight the sideslip to zero. This must be with rudder will result in an unwanted In wings-level asymmetric fl ight, the prevented by the pilot in order to sideslip accompanied by an increase in yawing moment caused by the maintain the balance of forces and drag and a possible reduction in climb asymmetric thrust is balanced by a moments, and he does this by holding performance. The rudder deflection moment generated by the fin-rudder a greater rudder deflection and apply­ and fo rces will be less than the wings­ combination (see Figure 2). Although ing greater rudder pedal forces than level case as the pilot does not have to (mainly on propeller driven aircraft); deflected; and having a second engine can rapidly the moments are balanced, the rudder would be necessary if the aircraft was overcome the aircraft's directional and • the combination of rudder and become disadvantages un less the pilot side force is not. This unbalanced stabi lity with additional rudder deflec­ flown without sideslip. • a irspeed. bank angle used to control yaw. fully understands the real level of per­ force accelerates the aircraft laterally Asymmetric flight with small bank tion. As well, there is only a small On the other hand, the rudder posi­ formance available with one engine until the drag caused by the lateral angles yawing moment because of the bank tion required for asymmetric flight, in inoperative and the precise techniques velocity - sideslip - is equal to the * * * * If the rudder side force is balanced by angle, which means that slower speeds addition to being affected by speed, which must be used in order to achieve rudder side force. The aircraft is now some force other than a drag force may be reached before loss of control nose attitude and engine power set­ Compared with a single engine air­ even these minimum levels. in steady-heading flight with a sideslip caused by the aircraft's lateral veloci­ occurs. In the determination of the tings, is also dependent upon: craft, a twin offers many obvious safe­ Of all the techniques and procedures velocity away from the live engine. But ty, the aircraft can be flown without minimum single-engine control speed • the a ircraft's directional stability ty advantages, not only in the en route peculiar to asymmetric flight, because the wings are level and the air­ sideslip. This condition may be achiev­ at the time of an aircraft's initial cer­ (if the sideslipping technique is being phase of flight, but during take-off and probably the least understood aspect is craft is in straight flight, the slip ~ II ed by using a small bank angle - tifi cation, it is of interest to note that used); approach as well. But the safety that the slip ball is no longer an indica­ - an acceleration detector ~­ the relevant a irwo r thiness re­ usually less than J 0 degrees - • rudder power; margins can be small indeed and any tion of sideslip. As we have seen in this ma· i~-rnrti'flow d1rec?- towards the live engine (see Figure 3). quirements perm it the use of bank • aileron drag, if the ailerons are advantages that may be realised by brief discussion, the slip ball can be in "------angles of up to five degrees towards the centre when there a re significant the live engine. . sides li p angles present, just as it can be The effect of sideslip out to one side when the aircraft is fly­ The best asymmetric performance for ing with zero sideslip. Attempts to a particular aircraft type will be a centre the slip ball with rudder when compromise between the performance flying with bank can result in un­ lost because of the extra drag whilst necessarily large rudder deflections sideslipping and that lost because of with high forces and crossed controls. the higher wing incidence, or angles of These effects can only cause a further attack, required fo r the increased lift degradation of performance, as will force necessary for banked flight. the simultaneous use of bank, sideslip and possibly large a ileron deflections A 'further effect' of sideslip is that to achieve a steady flight condition. rolling moments are produced because Unless the pilot appreciates these the aircraft has lateral stability. This is facts, he may be unable to obtain max­ commonly referred to as dihedral imum performance from the aircraft effect. If the aircraft has strong lateral he is flying. SIDESLIP ANGLE stability it may require corresponding­ SIDE FORCE DUE TO ly large aileron deflections to prevent LIFT- COMPONENT.. the aircraft rolling. In extreme cases, such as with degraded lateral control that may result from a system failure, t he rolling moments caused by sideslipping may be greater than those which can be produced by the controls. This would cause an uncontrollable rate of roll until the pilot reduced the sideslip angle. I . Control position during LIFT SIDE FORC• COM•ON•NT ~~ asymmetric flight O bviously, the amount of aileron .and I rudder deflection required for steady asymmetric flight will vary from air­ craft to aircraft. T he position of the a ilerons wi ll be dictated by: • dihedral effect and magnitude of I sides lip; f. ~ • a ileron power; • rolling moments caused by rudder ~ deflection (particula rly with a large fin ~ SLIP BALL OFF CENTRE ' ' SLIP BALL CENTRED a nd rudder mounted high above the

a ircra ft's centre of gravity); WEIGHT WEIGHT • rolling moments caused by differences in a irflow over the wings fig.3. ASYMMETRIC FLIGHT WITH SMALL BANK AN&LE fig. 2. WIN&S - LEVEL ASYMMETRIC FLl&HT behind the live and failed engines page 24 page 25 -----~ --,,. ------

THE AUTO•PILOT DISENGAGEMENT The following account is part 189 degrees M. rest of flight the auto-pilot s har ing of potentia ll y REAL of a report received from the As the aircraft crossed the per fo r med faultlessly in dangerous experiences like pil ot of a PA-34 aerial am­ NDB at 3500 feet, it appeared whatever modes were this one can only result in an bulance, which was making a to me that the active selected. increa s ed safet y con­ night flight from Whyalla to thunderstorm a rea was mov­ On reflection, I realised sciousness by other pilots in THING L eigh C reek, South ing to the east, and I decided that, wh il e checking the similar situations. /\ ustralia, and return. ·to deviate to the west of track Woomera frequencies from The possibility of an oc­ Most readers will remember this 'The weather forecast had if the turbulence became too my RNC, I had accidently currence of this sort was in safety poster, which was published on the severe fo r the patient we had inc lud e d two oktas of switched off the auto-pilot by fact considered during the in­ inside back cover of Digest No. 86. cumulonimbus cloud and, ap­ on board. l accordingly un­ allowing the chart to come in vestigation of the fatal acci­ A conscientious pilot has just written proach ing Leigh Creek at 40 fo lded my Radio Navigation contact with the electric trim dent to a PA-31 at Golden DM E, we encountered an C hart to copy the Woomera switch on the left hand side of Grove, South Australia, on to point out, against himself, that despite a rea of thunderstorm activity N DB frequency and DME the control wheel. 13 July 1972, but there was the warning and the fact that he was wh ich extended to wi thin ten channel on to my knee-board, Although the aircraft was insufficient evidence either to aware of this particular danger, he found miles of our destination. We then swung around in my seat at no time in any danger dur­ support o r refute th is himself in exactly the circumstances fina ll y establi shed visual con­ to brief the ambulance atten­ ing this episode, it occurred to hypothesis. Tests conducted depicted in the poster - and a potential tact only five miles out, and dant on what I in tended do­ me that it could easily be during this investigation es­ tradgedy was avoided by the narrowest of carried out a n NOB approach ing. tablished however, that the otherwise in different cir­ margins. to the aerodrome. Having done so I turned cumstances. If it happened auto-pilot disconnect button When preparing to depart my attention to the controls for instance when the pilot on the control wheel of the This pilot writes: again , knowing there was this again a nd checked the instru­ workload is high enough to aircraft type involved, was ex­ I had begun to daily my aircraft at Kempsey one have fl owed straight down his throat! thunderstorm activity over ment panel. Immediately I a d versel y affect one's tremely sensitive, and that morning recently, fo r a fligh t to Tuncurry, when a yell It is bad enough that this incident occurred at all, the hills, I planned to clim b in saw that the aircraft was in a monitoring of the auto-pilot, disconnection could occur if fro m a friend caused me to swing around just in time to but it is rendered all the worse by the fact that, even as I t he circuit area to pass 20 degree bank to the left, such as during a climb in the button were gently tapped see him knocking a bottle out of his little boy's mouth. was taking the bottle out of the aircraft to do the water through 4000 fe.et before set.­ about 45 degrees off heading, with a sheet of paper, or even I MC after departing from a T he bottle was about a th ird full of green soft drink check I reme mbered so me time before reading a warning ting heading fro m Leigh and was now climbing a t only primary a irport on a complex brushed with a shirt sleeve. - in reality I00-130 octane aviation fu el! A fter carrying in the' Digest about: Creek. After taking off from a little over 100 feet per instrument departu r e s Although auto-pilot con­ runway 16, I turned left on to minute! clearance, when there is a t r o Is for rea sons of out a water check on one of the aircraft ta nks, I had plac­ e T he da nger of using soft drink bottles fo r doing water 070 degrees M a t 1400 feet, After re-establishing the high communications work­ operational safety, need to ed the soft drink bottle used for the purpose on the checks; a nd a nd left again on to 340 climb on a heading of 220 load as well, the situation ha\'e the capacity to be readi­ ground, still with the " green stuff' in it, while I continued • Leaving fuel samples lying around in a container, degrees at 1700 feet. At 2500 degrees to intercept the track could be potentially very ly and quickly disconnected with the inspection. rather than emptying it straight away, so preventing it feet I engaged the auto-pilot of 189 degrees, I checked the hazardous indeed.' when the need a rises, it is Obviously the little chap had felt like a drink and becoming a temptation to thirsty or curious little people. master switch, the heading auto-pilot and found the possible that control column was a bout to begin sa mpling the interesting looking li­ I hope this experience m ight assist in some way to hold and auto-trim, and set master switch off. I therefore Comment switches of this type may be quid in the bottle. He hadn't qu ite got the bottle into a em phasise the necessity for extreme caution whenever up a climb at 700 feet per disengaged the auto-trim and too p rone to inadvertent horizo nta l position when his father knocked it away. children. a re in the vicinity of aeroplanes. minute and 110 knots, and heading hold, turned on the We very much appreciate our o pera tio n a nd they a re This proba bly saved his li fe, for he is one of those then, on the auto-pilot, I auto-pilot master switc h cont ributor's c oncern for currently being examined by kids who puts the neck of the bottle right into his mouth. positioned the aircraft to again, a nd re-engaged these safety in bringing this inci­ the Department. ".'.'- - - ·/~ overfl y the NDB on a track of two modes. Throughout the dent to our attention. The So if he had tipped the bottle any fu rther, the fuel would page 27 page 26 AMoo·t P U)-· z c Ill .Q"' Not long ago, the owner-pilot A. -j of a Cessna 172, telephoned a CJ Main tenance Organi sation at A. "'~ Parafield, from Ki ngston, ..,_. l :i South Australia advising that a. c Q) 0 his ai rcraft's had Top Outboard edge of starboard tailplane "' >i been damaged and that he - showing buckling of skin. The tailplane ::c c 0 wished to bring the a ircraft in is upside-down in the picture. Q) - for repair. c g> Apparently, wh ile the air­ Centre 1- "' Hidden damage revealed after tailplane 0 ·­ craft was left parked in a pad­ was removed from aircraft, the leading E c dock, a cow had taken a fancy edge is buckled and has separated - E ~ to the shade it offered and from spar. ... 0 a. had settled herself comfor­ CJ ('CJ tably under the tail section. Bottom ... Cl) .c Evidently then, when the The torn and buckled main spar. -a.·-"' owner-pilot had returned to I-- E :5 resume hi s journey, the cow, engineer of the maintenance f/) possibly upset at having her workshop, prevailed upon the en 1: rest disturbed in thi s way, had pilot to remain where he was, stood u p somewh at too and despatched an engineer in Q ...~ suddenly, giving the underside another aircraft with a a. of the tail plane a heavy blow. replacement tailplane. It was z c As the damage seemed to be as well he did. W hen the ('CJ confined to some minor den­ damaged tailplane was ex­ c CJ ting and buckling, plus a few amined, it was found that it scratches as shown in the fi rst had been seriously weakened two pictures, the pi lot thought internally, with a torn and it would be a ll right to fly the buckled main spar, as well as intervening 220 kil ometres to separation of a Parafield to have the damage rib from the buckled spar repaired. bulkhead. Fortu nately, the chief Would the tailplane have failed if the pilot had attempted to fly the aircraft to Parafield? Who can tell - it wou ld pro bably have depended on the intensity of the turbulence encountered during the trip. What is cer­ tain is that the structural strength of the tailplane was greatly reduced by the unseen - internal damage, and to have flown the aircraft in that con­ dition would have been a risky venture indeed. Thanks to the vigilance of the chief engineer however, there was no possibility of this developing into another fatal object lesson in air safety. Thus, happily for the pilot concerned, it is one that he, as well as other readers of the Digest, have the opportunity to learn from.

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