Originally Posted by Trim Stab
Interesting that you flew 2 engined approach so much slower than the asymmetric approach. If on a 2 engined approach you had to do a "real" go around, and then had a flame-out as you applied full power, would the aircraft have remained controllable?
Originally Posted by WarmandDry
Certainly know of one case of a surge on short finals where they ended up touching down parallel to the rw but landed across the unoccupied QRA pans and all got out but with minor injuries (even the pax in the jump seat).
Another case, from my experience – 45 Sqn B15s at Kuantan in Malaya on detachment 1963-4. Experienced crew, doing a low overshoot from a standard full flap approach, had Trim Stab’s flame-out and settled as a result into a rubber plantation a mile or more upwind. In this case I remember that none of the crew had a scratch, but I fear the memory is not what it was. Suffice to say we all felt we were just not entitled to survive such an accident and that our friends, this time, were amazingly lucky.
Actually, flame-out it was not. We never heard of flame-outs at low level, although some crews regularly lost power in this way at height, in or around cu-nims.
The design of our Avon engines incorporated two deliberate fudges to account for a mismatch between the compressor at the front and the turbine at the back. The airflow was of course optimised for high RPM. The first fudge concerned the way the first stage of the compressor received the incoming air. The air might usually have been directed into the compressor by “stators”. The Avon’s equivalents were called “swirl vanes” and were not fixed but had two positions. As I remember, they changed position at 6100 RPM. If they did not the engine would surge on acceleration – but I never heard of this mechanism actually failing. Others have mentioned the icing drill – 6000 RPM was significant because the swirl vanes would at least be in their approach configuration whatever ice they collected.
The other fudge arose because, the compressor and the turbine being ganged together, at low RPM the compressor pulled in more air than the combustion stage could burn. Bleed valves would open to exhaust this excess air. If when the engine was being run up they remained open, then the engine would settle at the RPM at which they should have closed and would no doubt generate not enough thrust. As I remember, the critical range was 2800 to 3200 RPM. One would always watch the gauges to make sure this phase was safely passed, and then be more casually interested that the needles twitched appropriately going through 6100 RPM.
The Kuantan case was of a bleed valve failure. The aircraft was comfortably airborne and might have accelerated away if it was not for the flaps.
As has been mentioned, the Canberra’s flaps were either up or down. On selection, either up or down, they moved very deliberately. When down they were very effective.
So the flaps are down. One of the hydraulic pumps is underperforming along with its associated engine. If the pilot tries to raise them, both the undercarriage and the flaps would come up more slowly than normal. Apart from that, the pilot has at least one throttle bent forwards and an ache is developing in one leg. He may or may not be trying to bring the dud engine down and up again. But his eyes will be fixed on the air speed indicator and he will be disappointed to realise, knot by decreasing knot, that the flaps remain more effective than the one good engine. Happily he makes the one really critical decision and closes the good throttle – and the god of rubber plantations is kind to him.