Air Safety

But on this Droverat least, David was determined that the rot would go no further – if he had his way it would be one of the best Drovers still operating in the country. Already he had refurbished the cabin to a fair semblance of the type’s original airline configuration, and the weathered duralumin fuselage and wings were beginning to respond to repeated applications of Turco powder and elbow grease. The aeroplane was beginning to look like an airliner – a thing David considered important for passengers conditioned to 727 and DC-9 travel.

The only trouble was that the Drover, with its three Gipsy engines, needed a good deal of maintenance. Although David was authorised to do a lot of the minor work himself, the Drover had to be flown to Albury or Wagga for anything more than this, and far too much of his earnings were going in wasteful ferry time.

This morning, with the school holidays now over, and tourist business beginning to taper off in Tullaberga, David had resolved not to do any flying. The Drover had been working hard over the past weeks and was due for some much-needed ti ing including a good look inside the cowlings and an o change on all three engines. There was also the recurring problem of a sticky valve in the starboard engine-something that should have been attended to a week or more ago. But with so much flying, there just hadn’t been time for the half day’s work it involved.

Anyway, today wasn’t a particularly good day for flying. There was a strong southerly blowing which, as well as whipping up big seas and a lot of spray, could make things decidedly uncomfortable for passengers at sightseeing altitude along the coast.

That at least had been the way David felt. But now as he answered the telephone and an authoritative voice enquired about a flight, David felt his resolve weakening.

Stuart McAllister, a man whose name David knew as a senior company executive in Melbourne, wanted the Drover to take a party of nine passengers up the coast to Merimbula and return. David found it hard to refuse. It was good business, with the chance of furthering his reputation, and the trip would take up very little of the day.

In fact McAllister wanted to leave as soon as he could, and David found himself being pressured into nominating a depar- ture in half an hour’s time. It would barely allow him to get the Drover back into flying condition, let alone complete a full preflight inspection, but he’d flown several trips the previous day and all had been as it should be.

David had pulled the Drover from the hangar, tested the tanks for water and was checking the oil levels, when the cars drew up in the parking area. The passengers, obviously a family party, ranged from an elderly matriarch to a precocious school- boy full of questions, but they boarded the Drover with the assurance of travellers well accustomed to flying.

David pulled away the steps, climbed in himself an closed the cabin door behind him. Latching it, he made his way forward past the passengers already busy securing their belts. McAllister himself, sitting on the starboard side and holding an eight-millimetre cine camera, stopped him.

“Can we open any of these windows? I want to get some footage of the wrecks near Cape Howe and also the spot where the Lyee Moon went down. Do you know where I mean?” David nodded. The wild coastline between Cape Howe and Twofold Bay was littered with the bones of ships that had succumbed to its treachery, but the wreck of the old steamer Lyee Moon and the lonely windswept graves of its victims not far from the lighthouse on Green Cape was better known than most.

“I’ll do a low run over the Cape and a shallow turn around the light. When I lower a bit of flap you can open that hatch opposite the door at the rear of the cabin-it was put there for supply dropping when this was a Flying Doctor aircraft. Just make sure you latch it when you’re finished – when I hear it close I’ll put on power to climb. ” Leaving the tiny cockpit door open so that his passengers could see something of what he was doing, David settled himself in the left hand seat and fastened his harness.

The port and centre engines started normally, settling down to their characteristic chatter, but as he pressed the starter button for the starboard engine, David felt it jump quickly over the intermittent weak compression.

Sticky exhaust valves are not uncommon in Gipsy Major engines but will often clear themselves as the engine warms up. David continued with the start, expecting the problem to cure itself, as it had each day over the past week.

With his passengers aboard and ready to go, there wasn’t much choice. The only remedy entailed pulling off the rocker gear and exhaust manifold, pushing the valve up into the cylinder and passing a reamer gently through the valve guide.

The engine fired, coughed once or twice, then ran vibrating in its mountings under the effect of the misfiring cylinder, as David throttled it back to 1000rpm.

There was no immediate sign of the misfiring clearing – clearly the problem was getting worse. But not relishing the alternative, David released the brakes and taxied to the runway threshold.

At the holding point he waited again. The engine was still running like a chaff cutter but was at least showing signs of clearing itself. While he waited, David completed the takeoff check list and ran up the port and centre engines. Yet still the starboard engine wasn’t right. It would run smoothly for a few seconds then, as the throttle was opened further, the offending valve would stick again.

Back in the cabin, some of the passengers, realising this was an unusually long runup, were beginning to look at one another questioningly. No one would blame him, David knew, if he simply taxied back and told them the aircraft was unserviceable.

Yet he was reluctant to abandon the flight. Apart from needing the money, his customers were clearly influential people whose word might be the making or breaking of further business of this sort. And surely, David thought, the engine would come good in a minute or so.

At length it did, but not before the Drover had been at the holding point for a full 20 minutes.

Running the starboard engine up once more to full power with no further sign of hesitation, David took a final look around, and turned the Drover into wind.

Slowly now, more than usually alert for the slightest sign that he should discontinue the takeoff, David opened the throttles together. The chorus of the engines rose to a crescendo and the Drover surged forward, gathering speed. But this time all was well, and the aircraft lifted off normally, climbing away steeply under the effect of the stiff headwind.

Playing it safe, David continued the climb straight ahead until he was sure there would be no further problem with the engine. At 1500 feet, he turned downwind over the sea, setting course for Gabo Island and Cape Howe, a heading which would take the aircraft just to seaward of the beached wreck of the old Riverina. At this altitude too, they were clear of the turbulence the southerly gale was producing in the lee of the exposed headlands and hills.

Twenty minutes later, crossing Disaster Bay as the Drover approached the jagged finger of coastline that is Green Cape, David throttled back and eased the aircraft into a shallow descent. At 500 feet he lowered some flap and banked into a shallow turn around the lighthouse and the little group of headstones nearby – all that now remained to show that these rocks had once been party to a disastrous shipwreck.

A sudden rush of air at the rear of the cabin told David that McAllister had opened the hatch for his filming. Glancing behind, Davidsaw that most of his passengers were out of their seats, eyes glued to the starboard windows.

Allowing them time to take in the view, David held the aircraft in a wide descending orbit around the headland, crossing the Cape for the second time 200 feet above its scrub covered surface. The turbulence here wasn’t too bad, but he would need to climb again before the aircraft got too close to the higher country further north.

Good as his word, McAllister closed the hatch promptly and, as the Drover swung back on to its original heading, David pushed the throttles forward and raised the flap.

He was still trimming the aircraft into the climb when he felt the sudden yaw and heard the smooth bellow of the engines drop into an unsynchronised beat. Instinctively he corrected with rudder as his mind flew back to the rough running before takeoff. But no- this time it was the engine on the other side. His eyes flicked over the panel – the port tachometer had dropped to 1200rpm.

Impulsively, he reached over and thrust the throttles of the two live engines forward to full power. Immediately, the starboard engine began to leap in its mountings as the chronic misfiring manifested itself again.

David’s heart missed a beat and he felt the colour drain from his face. What a fool he was to get himself in this mess. Here he was with a full load of passengers, less than 500 feet above a wild sea, with one engine out and another running roughly. With its fixed pitch propellers, the Drover wouldn’t have a hope of maintaining height on its one good engine. There was nothing for it but a forced landing back on the Cape.

A bush airstrip of sorts had been bulldozed from the scrub a mile inland from the lighthouse, but it was hardly adequate for a Drover. The fish spotter pilots from Merimbula used it sometimes when they were flying for salmon in their Super Cub, but as well as being short, it ran downhill into the south towards the cliffs overlooking Disaster Bay.

David shuddered at the though. Well he’d just have to ground loop the Drover, even if it meant writing off the undercarriage. He’d never be able to stop otherwise. And he’d have to watch the approach too. The telephone line to the lighthouse crossed the northern end much too close to the threshold for comfort. Even so, the strip was preferable to the precipitous and heavily timbered coastline that extended for miles north and south of the Cape. He’d just have to get down there somehow – and quickly too. If the aircraft got too far downwind in this southerly, he mightn’t be able to complete a 180 degree turn and make it back to the Cape before the Drover sank below the level of the cliffs.

David swung around to face his passengers. “Fasten your seat belts please,” he commanded, hoping he sounded calmer than he felt.

Catching a glimpse of the lighthouse beyond the cabin windows, he was dismayed to see how far the strong tailwind had already carried them from the comparative safety of the Cape. They could be in real trouble. Full of fear now, with his heart beating wildly, David had to force himself to concentrate. If there were not going to be more lonely graves on that headland, it would only be because of his flying ability now. Making a deliberate effort to relax his tense grip of the control wheel, he trimmed out the nose-up pressure he’d been holding instinctively, and studied the instruments. The airspeed had fallen to 65 knots and the altimeter was very gradually unwinding. The loss of height was slow, but he knew that as soon as he tried to turn, the increased drag would sink the aircraft like a stone.

Desperately he went through his emergency drill for the ailing port engine, checking fuel, mixture and magneto – all without effect. Oil pressure was still registering, though a little on the low side, but no amount of throttle pumping would vary the engine’s steady 1200rpm. It was plain that the linkage had parted somewhere and the throttle had closed itself.

He looked again at the misfiring starboard engine. It had been running well enough until he put on full power after the other engine failed. Would it pick up again if he was game enough to ease back the throttle? If the gamble didn’t work they’d lose precious height even more quickly. But he really had nothing to lose – the way things were they’d descend into the sea anyway.

Heart in mouth, David slowly retarded the lever. At 1600rpm the misfiring ceased and the engine ran smoothly. Forcing himself to remain calm, he advanced it again gingerly, and the engine responded. He felt the aircraft surge as the power came on 1950rpm, 2000, 2050. Suddenly, as the tacho needle reached 2100, the smooth engine note collapsed again into misfiring vibration.

Quickly David pulled the throttle back until the rough running ceased, edged it forward again until the tachometer was reading 2000, and tightened the friction nut. Already now the aircraft felt better. With the unnerving vibration gone from the airframe and the starboard engine delivering close to cruising power, they might have a fighting chance.

David checked the flight instruments again. His experiment had cost them 100 feet, but the altimeter was no longer unwinding and if they could hold the height they had left now, they’d make the airstrip with about 150 feet to spare.

Encouraged, he eased the aircraft into a gentle turn to port. Turning in the direction of the dead engine wasn’t good asymmetric practice but this time he had no choice.

Holding the nose up as much as he dared, David was astonished to find that the Drover was not only maintaining height during the turn, but was actually gaining few feet. Then he realised that the trickle of power still being delivered by the failed engine was probably sufficient to offset the drag of the windmilling propeller, if not actually providing a small amount of thrust.

But even as he exulted in the relief this brought, it faced him with a new dilemma. Should he still go ahead and land on the Cape with the near certainty of crashing or, now that the aircraft was able to stay in the air, should he try and continue to Merimbula 30 odd kilometres further up the coast? There was little time to make a decision. Once he completed the turn into wind and came over the Cape at low level he was virtually committed to land. It would be foolish to risk another low level 180 degree turn at reduced airspeed in these conditions, and continuing back to Tullaberga into the teeth of the southerly gale was out of the question.

On the other hand, if he had no further difficulty maintaining height, the same wind would give them fast passage to Merimbula. But what if that starboard engine, now producing the power that was keeping them in the air, should repeat its trouble? True, there were two or three beaches on the way, long enough for a forced landing, but the greater part of the intervening coastline consisted of rocky headlands and near vertical cliffs.

David made up his mind. He would try for Merimbula. But as an added precaution he brought the doubtful engine back to 1900rpm. It should still be enough to fly – even if only just.

Straightening out of the turn on to a heading that would parallel the coast, David trimmed the Drover to fly straight and, a few knots above its minimum control speed, gradually nursed it back to 700 feet. It stubbornly refused to go any higher.

McAllister, puzzled by the aircraft’s manoeuvres, and knowing nothing of their slim margin of safety, strode forward to the cockpit. With the abrupt change of trim, the Drover lost 50 feet of precious height.

“Can’t we fly lower and closer to the foot of the cliffs? We’re too far out to get the shots I want. ” This was no time for detailed explanations.

“Would you mind going back to your seat?” David shouted over his shoulder, “we’ve got a bit of a problem”.

He returned his concentration to the bellow of the starboard engine. It sounded healthy enough now, but if that exhaust valve should stick again. . .

The Drover staggered on, just out to sea now from the coastal cliffs. About half way they passed the wide entrance to Twofold Bay and the fishing port of Eden. Now at least they were closerto aid if they had to ditch. Still apprehensive, David thought of Pam and their young son back at Tullaberga – people, like those in the cabin behind him, who were dependent on him. He had no right to have put any of them in this situation.

At the rear of the cabin there was a sudden rush of air as someone opened the hatch again, and the altimeter slipped off a few more feet as the increased drag took effect. David yelled back at the offending passenger and the hatch was closed. A thin crescent of sandy beach slid beneath the nose, then more rocky headlands, and another beach. One more stretchof cliffs, a river mouth, the last beach and they would be there.

Slowly the second hand of the clock in front of him ticked off the remaining minutes, and David knew they had made it.

Have you an air safety story to tell? Particularly one with a lesson that might save other pilots from making a similar error of judgment? If you have, write to Macarthur Job, c/-Australian Aviation, PO Box 3105, Weston Creek, ACT 2611. Contributors to this series are assured their anonymity will be fully respected! After they had landed, the passengers had been conducted to the terminal building to await a charter flight back to Tullaberga-all surprisingly philosophical about the “mechanical problem”, but still blissfully ignorant of their deliverance- David opened the cowling of the port engine.

There, sure enough, was the throttle pushrod hanging limply beside the carburettor. The reason was not hard to see. The fall joint needed adjustment for wear-something that would have been obvious from an adequate preflight inspection and which could have been remedied in 10 minutes.

Then and there David resolved that never again would he fly without first making a full daily inspection-nor would he trust to luck with a doubtful engine. He had won on both counts this time, but he could take no credit for either.

The next afternoon, after servicing the Drover in the fisheries hangar, he ferried it back to Tullaberga. Pam came to meet him at the aerodrome.

“Darling!” she exclaimed, her eyes wide with surprise as she greeted him, “You’ve grown grey hairs on your temple!”