Just wanted to give thanks for some more very good posts on this thread. One of the best things about PPRuNe is that we gain insight from each other.
Should we be mute after a fatality while grief might still hang in the air ?
Accidents are not good news, and this thread has highlighted that some would prefer discussion not to proceed, out of respect. Again I apologise for starting this thread with a forthright and provocative post at such a critical time. That was my personal reaction to the fact of the Canberra still claiming lives all these years since I flew it.
The resulting thread would seem to show considerable support for the view that a good time and place to discuss an issue is when it is topical. Thanks,
Milt and
wheelbarrow, for your thoughts on shared experience being of value to others despite possible insensitivity at a difficult time.
Most of us pilots seem to be able to get on with our lives during and after crises, but I doubt if any of us are totally insensitive. It is probably on balance worth continuing the discussion a little further. Sorry,
Fast Erect
Canberra Engine problems
There is ample evidence of the fickleness of the Avon 100 series engines on the earlier Canberras. Not everyone met the problem - thanks
Pindi for pointing out that it was possible to have a great tour without engines misbehaving. However,
wheelbarrow's eloquent statement mirrors my experience. Some anecdotal evidence follows:
One vaguely remembers trying to get airborne in strongish crosswinds- you just couldn't put the power on until rolling fast down the runway because the downwind engine would just surge and blow out. One equally vaguely remembers the things going out when you decided to do a turn at high altitude, N-over-root-T surge springs to mind as the name of the cause.
The asymmetric difficulty was clear in the 70s when Bassingbourne with its shorter runway had closed, and someone had the bright idea, now that there was 9000ft available nearly everywhere, of doing all single-engined appproaches flapless to avoid any short-finals trauma, only deploying the flap when landing was assured. That they needed to change an SOP because the single-stage-flap asymmetric configuration was dangerous was recognised then.
Those of us who were later glued to the T4 every second Tuesday or Thursday night for night asymmetrics recurrents got to know just how gentle you needed to be with the throttles during roller landings. You actually had plenty of time, even on only a 6000ft runway, to get it wrong once on a roller landing, throttle back, then painfully inch the throttles open again and get airborne: if you didn't get it right the second time, you would have been glad of the rule requiring you to use a 9000 foot runway! However, if you only flew the T4 twice in 6 months, your feel for the throttles tended to be awry at first, based on how the PR9 throttles felt, not a safe situation at all. A solution was for the trainee to steer on the runway while the trainer could finesse the throttles through the roller - the start of what us civvies would call CRM. But all of this could be done completely safely in a simulator.
A classic example of the 100-series Avon's ability to cause mayhem was the early 80s low-level display practice when an engine surged without any accompanying throttle movement or other obvious cause. Unfortunately this happened during a stabilised medium-power 2G 60-degree bank turn with full flap and gear, 150kts, brilliant way to do a tight turn in front of a crowd. Except that, as the engine blew out the aircraft suddenly rolled upright even as the pilot frantically kicked in the rudder. Good job it was the upper engine that surged, the lower one would have rolled them upside down - they were only at 250 feet. And that was only the start of their problem: - with barn-door flap and gear down, on one engine, trying to do a go-around from 250 feet from what had now become an unintended approach into a set of ploughed fields. For the record, the flaps eventually came up and they proved that if you have the right speed at the start, you don't need to start your asymmetric overshoot at 600 feet MDH to get away with it.
Milt - "I came close to flying a Canberra once that had been sabotaged!! I was flying one in an air display once on one engine when the live one quit. It was a good glider for a while. A story for later if there is interest." Amazing similarity - Please tell us more, Milt !
A PR7 had engine surges on take-off during the late 70s, in the 45 knot gap that Wheelbarrow mentioned below V2, and the crew ejected, leaving behind a jump-seat junior navigator to crash into brick walls alone.
As another example of the early Avon's surge problems, during an OCU course in the 60s, a colleague, far better and smoother pilot than I, was caught by an engine surge during a Canberra practice stall recovery over the North Sea. One engine went to full power, the other blew out to none: close to stall speed anyway, the aircraft quickly spun, down into cloud. Disoriented, he ordered his Nav to eject, then after the bang and before he could eject himself, he came out of cloud with enough height and horizon to visually recover and fly home. "Sorry about that" - the poor Nav without a goon suit nearly died in the cold sea, luckily had parachuted down near a boat that saved him.
So there are a number of pointers to the unreliability of the Avon 100 series engines, which are of course the key to why there is any need to practice asymmetric approaches in the first place. In 13000 hours on Boeings and Airbus kit since then I have never had an engine out. My record on 2000 hours on Canberras was similar to
Wheelbarrow's, a number of failures. To my mind, anyone who wants to dig a T4 out of maintenance and resurrect it ought to prove that it is safe and necessary to do so. No doubt all the accident stats are available, somewhere. To me, the case is beyond doubt : they were unsafe in the '50s, and they are still unsafe.
So - Unsafe ? Should they ground them all ?
Despite loving the "Queen of the Skies" as we all do, the title to this thread appears well founded.
On the whole though, we don't know what we don't know, only what we do know. So I'm grateful for well-reasoned posts from
Beeayeate and
Milt,
Instrument Ranting and others, and enlightenment from
Jackonicko who said
"...the damned things are of pivotal importance, and offer a unique capability. Useful they most assuredly are."
If that is correct, Jacko, I'll happily modify my stance. I'm amazed that nothing else in our or the US inventory can carry the same electro-optical oblique sensors, but the operational requirement for PR9s is definitely beyond my pay grade. If the people who decide do so on the basis that the PR9 might save another 9/11, there is clearly a trade-off against safety. I'll leave that trade for those of you who know better than me to make. So rest easy, Sir Brian and Buff.
The T4s are a very different matter. I'm not so sure that the case has been made here for continuing to risk pilots' lives by using dodgy first-generation Avon 100-series engines in 50-year old airframes with ancient seats and instrumentation to do roller or asymmetric practice landings. And simply no-one here has made the case for risking Navigators' lives as well. The T4s seem to be clearly unsafe, and probably unnecessary.
Anyone have a nice used T4 brass starter cartridge ? Expect it to start having historic value soon.
____
ACW599 - John - PR9/ T4 differences : you might start by looking here :
http://www.rafmarham.co.uk/organisat...n/canberra.htm
Cheers