engine failure on twin
Thread Starter
Joined: Jan 2009
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From: europe
engine failure on twin
just wondering about procedure during one engine failure on twin according Glasgow crash.
The investigators said that on time of impact rotor doesn'n rotate.I was thinking why pilot did not enter autorotation.As far as I now when one engine failure occur on twin engine helicopter the procedure is to apply collective up to get max power from the other engine.On single engine the correct action is reversed - the pilot need to lower collective to restore rotor rotation.
In Glasgow case if pilot follow procedure and after one engine failure he apply collective up and a second after the other engine flame out pilot had collective up with no power from engine and this can only cause rotor to stop.
Just wondering my behavior in situation like this but I have only experience on single engine piston - if one engine failure the first thing I would do will be lower the collective and pull cyclic to "help" the other engine regain RPM on rotor and then I would start to raise collective up and follow emergency procedure with one engine.
what are you thinking about it ?
regards
The investigators said that on time of impact rotor doesn'n rotate.I was thinking why pilot did not enter autorotation.As far as I now when one engine failure occur on twin engine helicopter the procedure is to apply collective up to get max power from the other engine.On single engine the correct action is reversed - the pilot need to lower collective to restore rotor rotation.
In Glasgow case if pilot follow procedure and after one engine failure he apply collective up and a second after the other engine flame out pilot had collective up with no power from engine and this can only cause rotor to stop.
Just wondering my behavior in situation like this but I have only experience on single engine piston - if one engine failure the first thing I would do will be lower the collective and pull cyclic to "help" the other engine regain RPM on rotor and then I would start to raise collective up and follow emergency procedure with one engine.
what are you thinking about it ?
regards
Joined: Oct 2006
Posts: 5,174
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From: UK
As far as I now when one engine failure occur on twin engine helicopter the procedure is to apply collective up to get max power from the other engine.
You adjust the collective to maintain a safe Rrpm. In a high speed cruise the power normally demanded may be higher than one engine can provide so the collective would be lowered to maintain Rrpm. Should it happen at a speed range where the remaining engine can contain it then leave the collective alone.
Joined: May 2002
Aviation Qualifications: ATP+Mil
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From: Downeast
As Fareastdriver states.....in most Multiengine Helicopters the Emergency Checklist will say something along the lines of "Adjust Collective Lever as required...." for a single engine failure.
After finding oneself flying on a single engine( which means two engine failures in some Helicopters), any subsequent engine failure emergency procedure is very similar to that of Single Engine Helicopters.
After finding oneself flying on a single engine( which means two engine failures in some Helicopters), any subsequent engine failure emergency procedure is very similar to that of Single Engine Helicopters.
Joined: Sep 2002
Aviation Qualifications: CPL
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From: Great South East, tired and retired
No need to raise collective - if you have been using more than 50% Tq with 2 engines, then when one fails, the other will ramp up to try to provide more than 100% Tq by itself.
The OEI limits might be 135% or even a bit more for 30 seconds to get yourself to a speed range where you can use less than 100%, or perhaps to cushion onto the ground. Often this would require you to reduce collective on engine failure, particularly if you have been in a 75% twin cruise, and the single engine is now trying to put out 150%.
The OEI limits might be 135% or even a bit more for 30 seconds to get yourself to a speed range where you can use less than 100%, or perhaps to cushion onto the ground. Often this would require you to reduce collective on engine failure, particularly if you have been in a 75% twin cruise, and the single engine is now trying to put out 150%.
