Vulcan Mishaps At Wellington
The RR Dewent, De Haviland Goblin as fitted to the Meteor and Vampire respectively suffered from compressor surge if accelerated too quickly from low RPM. At or below that speed the throttle had to be 'milked' to ensure that the engine didn't stall on you. Once you got the RPM up to around 8,000 or so then you could slam it forward and the engine would readily follow suit. This affected your ability to manoeuvre not being able to call on full power on demand. It was especially critical on final approach were if one was baulked then it could be difficult to get the power on to overshoot before arriving on the runway. Multi engined aircraft like the Meteor were even worse where one engine would respond and the other not leading to a large asymmetry of power at low speed.
Around five hundred Meteor pilots died because of that.
With the advent of later marks of the RR Avon and Bristol Siddeley Sapphire came the ACP (acceleration control unit). This was a device the measured the ratio of fuel being delivered compared with intake pressure and throttle demand. It would automatically allow as much fuel as the compressor would accept so that maximum acceleration was available. This enable the pilot just to slam his throttle forward knowing that the engine would be accelerated at its maximum rate.
Around five hundred Meteor pilots died because of that.
With the advent of later marks of the RR Avon and Bristol Siddeley Sapphire came the ACP (acceleration control unit). This was a device the measured the ratio of fuel being delivered compared with intake pressure and throttle demand. It would automatically allow as much fuel as the compressor would accept so that maximum acceleration was available. This enable the pilot just to slam his throttle forward knowing that the engine would be accelerated at its maximum rate.
The Vampire pilot talks of a then-secret ability for the Vulcan to immediately generate full power. When I read that I assumed it to be either/and/or the Take Off / Cruise switch and the JPT limiter switches, either of which would help out in times of need but I stand to be corrected. I was not aware of them being secret.
Pages 16/17 and 51 of the link
http://cdn.justflight.com/support/ma...Mk2_manual.pdf
Pages 16/17 and 51 of the link
http://cdn.justflight.com/support/ma...Mk2_manual.pdf
I don't own this space under my name. I should have leased it while I still could
Morton, the take off/cruise switch was, I believe, applicable only to the Mk 2 with 301 engines. The aircraft at Wellington, if that is the one referred to was a Mk 1. No I am not sure but I think the Mk 1 had a similar start system to the Mk 2 though not quite the Mass rapid.
Essentially they could go from power off to airborne in about 30-45 seconds. I watched one display scramble where one aircraft got airborne on 3 and another on 2 and a third spooling up after lift off. The captain in that instant was Dicky Bird.
Essentially they could go from power off to airborne in about 30-45 seconds. I watched one display scramble where one aircraft got airborne on 3 and another on 2 and a third spooling up after lift off. The captain in that instant was Dicky Bird.
