January 1969

Na.BO JANUARY '1969 elsewhere. At 1400 hours, the time by which the He had made many similar flights to Lake Car Though it would seem unlikely, in view of his aircraft's fuel would have expired, the Distress gelligo during the previous months and on a known respect for cloud, that the pilot would Phase was declared and an aerial search for the number of occasions he had diverted or termin have become unintentionall y caught in cloud with missing aircraft was begun from Bankstown, using ated his flight at alternative aerodromes because a consequent loss of visual reference, the possibility six aircraft. Shortly after 1600 hours, the pilot of what he considered was adverse weather over cannot be dismissed entirely. It has often been of a Cessna 337 sighted the burnt-out wreckage the ranges. He had also told his flying associates found that pilots with limited flying experience of the missing aircraft close to the top of a heavily that he would not "press on" into adverse weather. and little experience in realistically assessing timbered ridge in mountainous country, twenty He had explained that there was no urgency for weather conditions, can be oblivious to the fact miles south-west of Katoomba. him to complete his flights to Lake Cargelligo by that they are nearing the base of a cloud. They any particular time and he was prepared to wait are of course aware of the cloud cover above them, for any adverse weather to clear. From his remark * * * but seem to have no idea of its vertical distance to the tarmac attendant before departing on the and go on climbing without realizing that they will The site of the crash proved to be in such day of the accident, it is evident that the pilot suddenly be completely deprived of visual refer rugged and inaccessible country that the investi was well aware that there was cloud on the ranges ence. It is thus possible that such a situation could gation team were able to reach the wreckage only on this occasion. There was nothing to indicate have occurred in this instance. by winch from a hovering helicopter. Examina however that there was any greater urgency for tion of the site showed that the aircraft had struck him to get through to Lake Cargelligo on this Alternatively and perhaps more likely, in view the steep-sided timbered ridge, 75 feet below its particular flight than on any previous occasion. One of the propeller blades detached from its hub at of the indications that the aircraft was in straight crest, while flying level on a south-westerly head impact. Damage to the blades indicated that the pro and level flight at the moment of impact, it is ing. The height of the ridge at this point is 3,650 The actual weather situation on the morning peller was rotating at speed when the aircraft crashed. possible that the pilot, flying very close to the base feet above sea level. The aircraft was totally of the accident was influenced by a southerly of the cloud, might have been deprived of forward destroyed by impact and the fire which followed, stream above 2,000 feet, with light winds below visibility while still retaining visual reference in a and the pilot was killed instantly. Examination of this level. The stream had bacb;d slightly to the downward direction. In these circumstances, the the wreckage disclosed no evidence of any defect south-east as the morning progressed, and as a reconstructed, it is reasonable to assume that the pilot might not have seen the ridge before the air or malfunction which could have contributed to result there was a well broken cloud base at about flight progressed normaUy until the aircraft reached craft actually collided with the tree tops. the accident, and the intensity of the fire showed 1,50 0 feet in the Bankstown area. The cloud base the foothills of the Dividing Range approximately that the aircraft would have had ample fuel on rose and thickened progressively towards the ranges 20 miles west of Bankstown. Here the general There is a third possibility which must be con board for continuing the flight. for about 50 miles to the west of Bankstown, where level of the terrain rises steeply to above 2,000 sidered. After the pilot had turned back in the the crests of the ranges above the 4,000 feet level feet and it is probable that with the cloud base valley to the west of the ridge and was approach The pilot, who held a private licence, had were in cloud for most of the day. The cloud cover close to the tops of the ridges, the pilot would ing the ridge again, but this time from its north accumulated 180 hours' experience in the 19 dispersed to the west of the ranges and beyond have diverted a few miles to the south of his western side, it is possible that the aircraft's per months that he had been flying. He was regarded the Bathurst area the sky was clear. track to follow the lower terrain of the Warra formance was affected by the considerable down by his flying associates, including the flying instruc gamba Reservoir area and the Cox's River Valley. draught which would probably have formed in the tors with whom he had trained, as reserved in Although there was no eye-witness evidence It seems probable that, after following the Cox's lee of the ridge under the influence of the south his approach to flying and reluctant to take risks. from which the aircraft's flight path could be River Valley and the Jenolan River VaUey in the easterly wind. By the time the pilot realized that direction of the J enolan Caves, the aircraft crossed the aircraft would not clear the ridge, it might have the ridge on which the accident subsequently been too late for him to take any avoiding action. occuned but from the south-eastern side, and further to the north where the ridge is about 1,500 It is also possible that the pilot might have feet lower than at the accident site itself. It is fallen victim to the "false horizon" phenomenon evident from witness reports that the cloud base sometimes experienced when fl ying in mountain in this area at the time of the accident was about ous terrain. Such an error could have contributed 3,750 feet above sea level. At this point therefore to the aircraft's failure to clear the ridge in the it must have been obvious to the pilot that the existing conditions. higher ridges a few miles further to the west were T he precise sequence of events that comprised in cloud and that the possibility of his getting the mechanics of this accident can only of course through was remote. It is apparent that the pilot be a matter of conjecture. Whatever the actual The steep-sided ridge then decided to turn back to Bankstown and made circumstances were however, it is impossible to on which the aircraft a 180 degree turn to the left in the valley imme crashed. Note how the escape the conclusion that the accident would not diately west of the ridge on which the aircraft height of the ridge falls have occurred if the pilot had not persisted in his sharply to the right of subsequently crashed, in order to retrace his flight attempt to continue the flight in what were obvi the picture. path down the Cox's River Valley and over the Warragamba Reservoir. ously marginal conditions. It is probable however, that at the point where Cause the pilot attempted to recross the ridge, the cloud base was just above its crest, and to "squeeze The probable cause of the accident was that the through," the pilot would have been forced to fly pilot proceeded into weather conditions in which very close, both to the base of the cloud and to visual flight with adequate terrain clearance could the summit of the ridge. not be maintained. l AVIATION SAFETY DIGEST JANUARY, 19 69 3 for about 150 feet, then, with nearly all the air were! But despite this knowledge, in the excite craft's momentum dissipated, the wire recoiled. ment and exhilaration of his " beat up", he forgot T he aircraft was spun horizontally through about about one line until it was too close to avoid it. 180 degrees, the port wing and nose dropped, and Possibly, it was his very knowledge of the area it struck the ground violently at a high rate of that encouraged the pilot to indulge in his escap-, descent with almost no forward speed. As well as ade, thinking no doubt, that the operation would crumpling the port wing, dislodging the engine be safe because he knew it. It is significant that and breaking the propeller as shown in the photo in the first part of the "beat up," the pilot took graphs the whole airframe was buckled and dis care to lift the aircraft over two separate sets of torted to the extent that it was a virtual write-off. power lines. Amazingly, the pilot escaped with only minor injuries. All of which shows once again that no amount of familiarity or local knowledge is proof against the dangers of yielding (usually on the spur of the Comment moment), to the temptation to indulge in ostenta tious exhibitions of low flying. Words almost fail usl Such comment as could be uttered about an accident like this has been T he pilot in this case can consider· himself said so many times before in the Digest that it extremely fortunate to have survived-let alone to hardly bears repetition (e.g., see "There's Danger have escaped so lightly.

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