Avro RJ100 take off / landing question
First off, just want to say... first post here, have searched the forums and couldn't find the answer so but if this has been done, sorry
OK, my question involves the above aeroplane, I’ve been on a few flights recently and noticed something which i thought was unusual, have thought of plenty of reasons why it might be done, but now looking for ”the truth"
On the ramp, you can hear distinct start up noises on only 2 engines. Pilot then applies first notch of flaps (at most fields, on short fields like LCY it's full flaps)
Plane takes off and then at what seems like about 2-3000ft whilst the final stage of flaps are withdrawn there is a distinct change to the engine noise which sounds like a start up.
same procedure in reverse on landing, as the pilot deploys first stage of flaps, there is again a change in engine note which sounds like engines being shut down.
(Sorry for the big war and peace effort, nearly there)
I can thing of a view reasons why this might be done. Unpredictable yaw control from loss of one of the outside engines on take off, noise abatement and possibly some form of structural / aerodynamic limit.
So a few questions then..... (Still here then!)
1) Am I right? are engines being started and stopped in flight?
2) if so why?
3) Which engines 1 and 4 or 2 and 3
4) any other aircraft have similar restrictions (I know the venerable dash 7's pilots only apply 50% to 1 and 4 for part of the take off from Courcheval in France, but that's because of a significant change in RW attitude can make the front wheel go light over the transition. apparently a loss of power at that point could cause a catastrophic directional control problems… search for the dangerous airport database on t’internet for more)
Phew, thanks for putting up with my long winded rambling