- The Canberra - Unsafe in 1950, Still unsafe
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On the question of rolling after a sim asy landing, the reasoning is simple. The asy approach in a Canberra is fairly straightforward but is full of pitfalls for the unwary or hamfisted. The final part of the approach is particularly tricky [I use the term loosley] since there is a commit to land once the asy decision height is reached [600ft ISTR]. From then on, it is a handling exercise calling for judgement. Once the wheels have touched surface the exercise is over, but the CT can continue by carrying out a symmetric roller. The trickiest part of that routine is in carefully managing the engine acceleration. The previously 'live' engine has a propensity to accelerate far quicker than the 'cold', and if handled badly, one could experience either a 'cold' engine surge stall [leading to a total lack of thrust from that donk] or an asymmetric swing due to one engine producing full power whilst the other is still accelerating.
That is why the roller was carried out by the QFI and not the 'ordinary' sqn shag. That said, the QFI would often let the more experienced carry out the roller. Latterly, ISTR the rules were tightened up even further, a night roller from sim asy landings allowed to be handled only by only GSU QFIs.
[All trawled from happy memories, subject to correction by those with more recent experience...]
That is why the roller was carried out by the QFI and not the 'ordinary' sqn shag. That said, the QFI would often let the more experienced carry out the roller. Latterly, ISTR the rules were tightened up even further, a night roller from sim asy landings allowed to be handled only by only GSU QFIs.
[All trawled from happy memories, subject to correction by those with more recent experience...]
"That is why the roller was carried out by the QFI and not the 'ordinary' sqn shag. That said, the QFI would often let the more experienced carry out the roller. Latterly, ISTR the rules were tightened up even further, a night roller from sim asy landings allowed to be handled only by only GSU QFIs."
Were those the rules at the time of this accident?
Night asymmetric landing into symmetric roller on a dark night with no horizon? Quite WHY were such things happening? Night asymmetric full-stop and/or night asymmetric overshoots perhaps understandable (although questionable) - but asymmetric landing converting to symmetric roller? No way.
Were those the rules at the time of this accident?
Night asymmetric landing into symmetric roller on a dark night with no horizon? Quite WHY were such things happening? Night asymmetric full-stop and/or night asymmetric overshoots perhaps understandable (although questionable) - but asymmetric landing converting to symmetric roller? No way.
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Such was the Canberra's relatively docile handling qualities
Maybe it was considered docile in 1955 but not compared to modern aircraft where Vmca is often lower than the stall speed.
Tim McL: No-one could describe the Canberra on one engine as "docile". In all other respects, yes, but not asymmetric.
Apart from that, thanks for the link, Beagle, I've been waiting to read that report with some impatience. As I recall, (symmetric) rollers following an asy landing were done so as to achieve the required number of asy landings - the alternative being a long taxy round the airfield.
Apart from that, thanks for the link, Beagle, I've been waiting to read that report with some impatience. As I recall, (symmetric) rollers following an asy landing were done so as to achieve the required number of asy landings - the alternative being a long taxy round the airfield.
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I understand that it was docile when both engines were working as planned. On one engine, it could bite very badly - and very fast! Back in the 60s and 70s, the Canberra was a fast-jet posting - and only the very best were lucky enough to get to fly the PR9.
Sorry keithl, you beat me to it!
Sorry keithl, you beat me to it!
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Well technically-speaking it was a "fast jet" posting, but speak to anybody on the selection boards, and they would tell you that Canberra postings were traditionally reserved for pilots who would probably be better suited to Jaguars, Phantoms and the like, after gaining a little more experience on the Canberra, because it was judged to be a rather more docile aircraft (with both engines of course, but I think that rather goes without saying!) than the "fast fast jets".
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Beagle
Thank you for that link. I read the report with an overwhelming sense of sadness.
Frankly, in my opinion, the Board were kind to describe the supposed stagnation of the port engine as a causal factor. I would have described it as a contributory factor, in that it made the final accident more likely to happen. The main cause (again, in my opinion) was the failure, for whatever reason, of the handling pilot to apply the correct recovery technique whilst still on the runway. His options were to close both throttles, stabilise the aircraft and then either to convert to a full-stop landing or attempt to achieve stable and symmetric take-off thrust again. The figures in the report suggest that there was sufficient time and space remining to attempt either option, and still to abort if necessary. What was not a viable option was to attempt to fly away in a partially-asymmetric condition at the speed he had attained. The handling techniques for this aeroplane have been derived from hard-won experience. I disagree with the premise that it is inherently dangerous, but it is not docile and demands great respect. There is no substitute for application of the correct handling technique.
In general, I agree with your comments about aborting roller landings in 4-jets, where the likelihood is that the abort would be potentially more hazardous than flying away on 3. You must realise, however, that the asymmetric un-reheated 2-jet is a different case. The per-centage loss of thrust is greater, and the asymmetric moment may be more severe. In combination these will often make a fly-away very hazardous, whilst remaining on the runway offers the use of brakes, perhaps a barrier, and perhaps gear retraction as viable stopping aids. Ultimately, you might also have a viable ejection option, if taken early enough.
Regards
Ginseng
Frankly, in my opinion, the Board were kind to describe the supposed stagnation of the port engine as a causal factor. I would have described it as a contributory factor, in that it made the final accident more likely to happen. The main cause (again, in my opinion) was the failure, for whatever reason, of the handling pilot to apply the correct recovery technique whilst still on the runway. His options were to close both throttles, stabilise the aircraft and then either to convert to a full-stop landing or attempt to achieve stable and symmetric take-off thrust again. The figures in the report suggest that there was sufficient time and space remining to attempt either option, and still to abort if necessary. What was not a viable option was to attempt to fly away in a partially-asymmetric condition at the speed he had attained. The handling techniques for this aeroplane have been derived from hard-won experience. I disagree with the premise that it is inherently dangerous, but it is not docile and demands great respect. There is no substitute for application of the correct handling technique.
In general, I agree with your comments about aborting roller landings in 4-jets, where the likelihood is that the abort would be potentially more hazardous than flying away on 3. You must realise, however, that the asymmetric un-reheated 2-jet is a different case. The per-centage loss of thrust is greater, and the asymmetric moment may be more severe. In combination these will often make a fly-away very hazardous, whilst remaining on the runway offers the use of brakes, perhaps a barrier, and perhaps gear retraction as viable stopping aids. Ultimately, you might also have a viable ejection option, if taken early enough.
Regards
Ginseng
Ginseng, I agree with you.
'GO' mindedness during a roller landing may well have been a cognitive failure, in my view, with the handling pilot 'reverting to instinct' which, as you point out, was totally incorrect in this instance. I've never flown a Canberra, but for each of the 3 back seat Meteor T7 trips I scrounged at Brawdy 30+ years ago the brief was always the same - "Engine failure below *** knots and I will close both throttles and we will ride it into the barrier - above *** knots I will jettison the tanks and ask you for help with full rudder; I will be working hard!" The Meteor pilots at Brawdy never fly more asymmetric than was essential and treated the venerable old aeroplanes with great caution. Completely different techniques to those in the Buccaneer, Phantom or VC10 (the only multis I've flown) - which is why the astonishing concept of routine practising of aborted rollers in all STC aircraft I consider to be unacceptable.
I am unaware of the orders covering night asymmetric flying practice in the Canberra, so cannot comment further.
But to fly symmetric rollers after asymmetric landings in order to 'get more asymmetric landings without a long taxy round the aerodrome' seems an avoidable compromise of flight safety for expedience. Even more so at night.
'GO' mindedness during a roller landing may well have been a cognitive failure, in my view, with the handling pilot 'reverting to instinct' which, as you point out, was totally incorrect in this instance. I've never flown a Canberra, but for each of the 3 back seat Meteor T7 trips I scrounged at Brawdy 30+ years ago the brief was always the same - "Engine failure below *** knots and I will close both throttles and we will ride it into the barrier - above *** knots I will jettison the tanks and ask you for help with full rudder; I will be working hard!" The Meteor pilots at Brawdy never fly more asymmetric than was essential and treated the venerable old aeroplanes with great caution. Completely different techniques to those in the Buccaneer, Phantom or VC10 (the only multis I've flown) - which is why the astonishing concept of routine practising of aborted rollers in all STC aircraft I consider to be unacceptable.
I am unaware of the orders covering night asymmetric flying practice in the Canberra, so cannot comment further.
But to fly symmetric rollers after asymmetric landings in order to 'get more asymmetric landings without a long taxy round the aerodrome' seems an avoidable compromise of flight safety for expedience. Even more so at night.
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Beagle
On your last point, there is another factor to be weighed in the balance. Stopping rather than rolling implies use of the brakes, which will therfeore be partially heated. A subsequent taxy round would involve more braking, and therefore more heating (steering on the ground is be differential braking of the main wheels). The Canbera brake units would not take too much of that without suffering a considerable degradation in the remaining braking action available. This would invalidate the normal Stop and EMBS speed calculations for the subsequent take-off, and increase the risk of brake fade and possible brake fire if the second take-off had to be abandoned. On the other hand, there were established techniques for reacting to a thrust asymmetry during the roll fro an asymmetric approach, and it was a possibility that always had to be expected.
Regards
Ginseng
Regards
Ginseng
A valid point, of course.
What were the 'established techniques' in force at the time of the accident? Did they mandate specifically who was permitted to handle the a/c during a symmetric roller following an asymmetric landing?
What were the 'established techniques' in force at the time of the accident? Did they mandate specifically who was permitted to handle the a/c during a symmetric roller following an asymmetric landing?
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The established techniques were as previously described. Asto the rules, I will not comment as they may have changed since my time, but I note that the Board never suggested that the Captain was incorrect to allow the handling pilot to perform the roller.
The lack of any effective communication from, or between, the pilots is sad but not surprising. They would have been very busy trying to diagnose what was going on. More years ago than I care to remember, I experienced an aborted take-off (from a standing start) due to an asymmetric condition. Despite 2 violent swings to the left, there was not a word from the front until the throttles were finally closed. The first words uttered were then "The port fire light has come on. What shall I do?". My reply is best not printed here.
Regards
Ginseng
The lack of any effective communication from, or between, the pilots is sad but not surprising. They would have been very busy trying to diagnose what was going on. More years ago than I care to remember, I experienced an aborted take-off (from a standing start) due to an asymmetric condition. Despite 2 violent swings to the left, there was not a word from the front until the throttles were finally closed. The first words uttered were then "The port fire light has come on. What shall I do?". My reply is best not printed here.
Regards
Ginseng
Bugger....
Brain fart! But it was a while ago..
There was also a horrible p.o.s. called the Jetstream.... Nastiest heap of poo I ever flew.
Brain fart! But it was a while ago..
There was also a horrible p.o.s. called the Jetstream.... Nastiest heap of poo I ever flew.
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Indian Air Force T.54s had no ejection seats!
While researching an article about Indian Air Force Canberras I ran across the stunning fact (verified by 2 different IAF Canberra pilots) that the T.54s (otherwise identical to the T.4s of the RAF) did NOT have ejection seats for the pilots! The pilots just carried parachutes. The navigator strangely enough, had an ejection seat. I guess that was make the navigator feel better about not having an ejection seat in the IAF's B(I)58s!
Is anyone aware if some export T.4s were in this configuration? When the IAF bought the RNZAFs Canberra T.13s they were delivered with the pilots ejection seats.
My correspondents said they didnt feel like it was big deal because a lot of them had flown the single seat Vampire in training, which did not have ejection seats either!
Anyone here shed any light on why this was done? Financial reasons? Surely it would have cost more to modify the 7 odd T.54s to be without ejection seats than to just have them be in the standard T.4 configuration.
The mind boggles!
Worf
Is anyone aware if some export T.4s were in this configuration? When the IAF bought the RNZAFs Canberra T.13s they were delivered with the pilots ejection seats.
My correspondents said they didnt feel like it was big deal because a lot of them had flown the single seat Vampire in training, which did not have ejection seats either!
Anyone here shed any light on why this was done? Financial reasons? Surely it would have cost more to modify the 7 odd T.54s to be without ejection seats than to just have them be in the standard T.4 configuration.
The mind boggles!
Worf
