Air Safety

During my preflight inspection in pouring rain, I did not clamber up and removed the fuel tank caps to physically check the tank contents, but as I had fuelled the aircraft brim full two days before and the gauges still indicated full, there was nothing to suggest the tanks were not as I had left them. My flight plan thus showed an endurance of 335 minutes. As the total time interval worked out at 225 minutes,this left us a good safe margin on top of statutory reserves.

My passengers turned up as arranged soon after 0930 hours local·time and we taxied out. Immediately after takeoff, because visibility was poor and our track directly towards the Great Dividing Range, I climbed to 2,500ft over the field. At 0952 hours I passed our departure to Coffs Harbour, on climb to 10,000ft.

It was still raining heavily and at 3,000ft we entered cloud. On reaching our cruising level 15 minutes later, we were just below the cloud tops and began picking up a little rime ice, so we descended to 9,000. This shed most but not all the ice, and a little later we descended again to 8,000.

We continued what my old instrument instructor would have called a “useful IFR flight” in heavy rain and unbroken cloud. By the time we were approaching Wagga two hours later we were encountering a few breaks, but the freezing level had decreased as we moved further south and again we began picking up ice, necessitating a further descent to 7,000ft.

Around Albury we became fully visual and I requested descent to 4,100ft (our Lowest Safe) in preparation for landing at Wangaratta. Our approach was fully visual; overflying the field, I had a look at the sock, picked up the downwind leg, and landed into wind on the eastern runway.

Starting up again half an hour later, we taxied to the holding point. At this stage I remember checking the fuel gauges and telling myself we had plenty for the remainder of the flight. Our time interval to Wangaratta had been three hours, so our remaining endurance should have been 150 minutes. I had of course been using the wing tanks alternately during the flight to keep the aircraft balanced.

Pre-takeoff checks complete, we took off and set track for Eildon Weir on climb to 6,000ft. But the strong easterly stream blowing over the ranges was now producing quite extreme mechanical turbulence, and Melbourne Flight Service asked if we had the current Sigmet on severe turbulence below 10,000ft.

“You can say that again,” I retorted in non-procedural phraseology. “Request climb to 8,000. ” Climb to 8,000 we did, which put us on top of a layer of cloud where conditions were more comfortable. After passing Eildon Weir we were cleared to descend, initially to 7,000, where we reentered cloud. Further descent clearances were passed to us as we continued towards Moorabbin, and we finally became visual again at about 4,000ft, shortly before reaching the prominent Academy approach point, six miles north-east of the field.

We had been cleared down to 3,000ft and at this stage I moved the fuel selector from right to left tank in preparation for landing. Melbourne Approach then instructed: “Over the Academy, leave controlled airspace on descent, call Moorabbin Tower on 118. 1”. This I did, informing them I had Information Quebec, which was for Runway 13 Left. The tower then instructed: “Join on base for Runway 13 Left, report on base. ”

My lady passenger turned to me as I replaced the microphone. “What a wonderful flight,” she said. “The most wonderful experience of my life. ”

She spoke too soon – no sooner were the words out of her mouth than, without the slightest warning, the engine cut completely!

Immediately I transmitted a Mayday call. It was now about a minute since we had left 3,000 and, with the Academy now behind us, we were down to 2,500 feet over Melbourne’s closely settled south eastern outskirts. Quickly surveying the suburban sprawl, I told Moorabbin that I could see two green patches to my left, but they were too small. In any case one had people on it and the other obstructions. Within gliding distance too there was a drive-in theatre, but I knew that would be quite impossible-the forest of steel speaker posts combined with the uneven surface would smash us to pieces in seconds.

There was nothing for it, I told Moorabbin, but to go for one of the main roads and try to put the aircraft down between the traffic. There was no other option: the airport itself was beyond gliding range – we just wouldn’t have made it. Moorabbin Tower came back with: “Report after landing”. I thought “big deal” – and wondered!

By now we were down to 1,500 feet. I had a choice of a couple of major roads, but Wellington Road seemed the most obvious; running due east, it now lay directly below us and nearly into wind. The main road at right angles to it-Springvale Road – was all cars and trucks! Turning left to line up with Wellington Road, I kept as much height in hand as I could while I selected the most likely looking section.

A dual highway,Wellington Road’s east bound and west bound lanes are separated by a median nature strip on which there are small trees and tall steel poles which support street lamps overhanging the road on either side. I also saw now that there were power poles on the outside verges of the road as well. It was going to be tight-even apart from the stream of cars! I was terribly conscious too of the need to avoid power lines; I knew they would be there, crossing the road at frequent intervals! Even so, for a forced landing from our unenviable position and height, the east bound lanes immediately to the east of Monash University looked by far the most propitious. As we descended, I began keeping a sharp lookout for wires, determined to see them in time to take avoiding action. We were getting down towards power pole height before I finally did so – five or six heavy high tension lines stretched over the road together only about 50 metres ahead of us! And further on up the road were more! But if we could just clear the wires in front of us, I thought, we would be right – there would be room to get below them before we reached the second set! Still with speed in hand to clear the wires without difficulty, I lowered the undercarriage.

Wheels down, we were now only about 10 feet above the height of the wires. This was intentional – to be ready to dive below their level as soon as we had passed them – and put the aircraft down on the road in the 50 metre gap that existed for the moment in the east bound traffic. But then I realised that two cars a little ahead of us weren’t going as fast as I thought, and that at our present speed we could be in real danger of hitting them from behind.

I eased back on the control column, put down some flap, and brought our speed back to around 80 knots. Then we were upon the wires- and there was nothing more I could do but lift the aircraft over them before pushing the nose down hard to duck below their level while I had the chance. For a moment the bunt produced uncomfortable negative G – but then we had done it!

Our troubles were still not over. Almost immediately I saw that the starboard wing was going to clip one of the street lamps overhanging the road! More ducking and weaving was going to be needed before we would be safely down! And the crosswind now affecting us wasn’t helping! Lifting the starboard wing with aileron to clear the lamp as it floated up towards us, I kept the aircraft aligned with the road, using opposite rudder. But we must have side-slipped slightly, for suddenly there was a loud metallic bang on the port wing as its tip struck the top of a power pole on the left of the road. The impact tore off about a foot of wing and about half the port aileron.

Straightening out, strangely with no noticeable deterioration in controllability, I then saw that the starboard wing would hit the next street lamp stanchion on the median strip. Only a few feet above the road now, I missed the pole by kicking the aircraft into a wings level skid with rudder and opposite aileron. I was doing my utmost to keep the aircraft in the middle of the east bound carriageway to give the wing tips maximum possible clearance there was very little to spare. Distracted immediately afterwards by the danger of hitting a substantial bus stop shelter at the curbside just a little further ahead, I failed to see and avoid the steel post of a “No Standing” sign at the side of the road. The leading edge of the port wing hit it, knocking the post clean out of the ground. By this time we were either on the ground or so close to it that it no longer mattered. The actual touchdown was quite normal and we rolled on up the slight gradient in the road for about 500 metres before coming to rest. The two cars that had been in front of us had vanished into the distance, their drivers blissfully ignorant of the drama that had just unfolded behind them! The drivers of the three vehicles following us, swallowing their astonishment, had taken their own avoiding action. By the time we were climbing out, they too had stopped and were all around us. They helped me to push the aircraft off the road.

In a few more moments another aircraft was circling overhead. On the radio I heard its woman pilot reporting to Moorabbin that we were safely down.

* * *

After the Bureau of Air Safety’s investigators had finished looking at the aircraft in situ, it was dismantled and taken to Moorabbin by lorry. Apart from the damage to the port wing, the other finding of significance was the lack of any quantity of fuel in either tank. On the basis of our flight time thereshould have been the best part of 100 litres still remaining. More than 80 litres were unaccounted for, and I can only conclude that this amount was ‘milked’ from the tanks by persons unknown while the aircraft was standing overnight at Port Macquarie. As I found out later, this had happened there to other aircraft.

But had this been the actual cause of the abrupt engine failure? Knowing my aircraft as I do, it still didn’t quite add up. The mystery was solved after I decided to have the 21O’s impending 100 hourly inspection, together with the engine’s 1500 hourly top overhaul, done at the same time as the repairs were being completed.

While the fuel system was being inspected, traces of water were found in the fuel injection manifold valve. Evidently, there had been small amounts of water in the sumps of the fuel tanks, and because the fuel level was so low during the final stages of the flight, this had allowed droplets of water to be drawn through the fuel lines into the injectors, stopping the engine dead!

How did the water get there? Had it been forced into the tanks, either through the tank caps or the tank venting system, by the heavy rain to which the aircraft had been exposed during the flight? Or had the normal preflight sampling failed to remove completely what was there before?

In the past there have been instances where folds or creases in the bottom of bag type tanks have prevented small accumulations of water from being completely drained by the drain cocks. The problem did not arise with tailwheel Cessnas, probably because the attitude of the aircraft on the ground moved any water to the rear of the tanks where the drain cocks are located. But with nosewheel types which stand on the ground in a level attitude, the gradient in the bottom of the tanks seems to be insufficient to always ensure that small pockets of water are completely dislodged.

There’s an old saying that you never stop learn about flying, no matter what your experience. From now on I’m not only going to gives the wings a good rock (and when I have someone to help me, maybe pull the tail down as well) while I’m doing my preflight before I sample the fuel, I’m also going to physically check the tank contents before the first flight of the day-instead of taking it for granted that they are full!

I hate to think what might have happened if that water had found its way into the system while we were still IFR over the ranges!