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-   -   Hercules crashed in Medan Indonesia (https://www.pprune.org/rumours-news/563776-hercules-crashed-medan-indonesia.html)

WingNut60 3rd Jul 2015 02:05

Awaiting the enquiry ??
 
Brian, or anyone else who knows the answer to a genuine question .....
This was a military flight from a military airport in Indonesia.
I am sure that there will be an enquiry. And there were certainly civilian fatalities, both in the aircraft and on the ground.


But is there likely to be a published report?

Dan Winterland 3rd Jul 2015 16:07

Indonesia does have an independent accident investigation body in their National Transportation Safety Committee and it's unusually open and transparent compared with other areas of Asia. However, this being a military accident, they may not be asked to investigate.

A Squared 19th Jul 2015 06:26


Originally Posted by Brian W May (Post 9031973)
In the RAF Hercules K simulator, we used to give an exercise that pitchlocked the prop at rotate.

It's not "uncontrollable", but does have to be handled correctly . . .

Pitch-locked prop at rotation wouldn't be a that big a deal. A prop malfunction with pitchlock is preferable to the same malfunction without pitchlock. Pitchlock prevents a uncontrolled overspeed and buys you time to get stabilized in the climb at a safe altitude before having to screw around with it. RPM will increase with airspeed, but that can be controlled with throttle reductions. There shouldn't be any aircraft controllability issues unless there's something else going on.

JammedStab 19th Jul 2015 07:05


Originally Posted by A Squared (Post 9051160)
Pitch-locked prop at rotation wouldn't be a that big a deal. A prop malfunction with pitchlock is preferable to the same malfunction without pitchlock. Pitchlock prevents a uncontrolled overspeed and buys you time to get stabilized in the climb at a safe altitude before having to screw around with it. RPM will increase with airspeed, but that can be controlled with throttle reductions. There shouldn't be any aircraft controllability issues unless there's something else going on.

As the airspeed increases, you will have to bring the throttle of the affected engine further and further aft resulting in more rudder required to maintain control.

Not sure if that is considered a controllability issue. But it does have to be dealt with one way or another.

A Squared 19th Jul 2015 07:15


Originally Posted by JammedStab (Post 9051188)
As the airspeed increases, you will have to bring the throttle of the affected engine further and further aft resulting in more rudder required to maintain control.

Not sure if that is considered a controllability issue. But it does have to be dealt with one way or another.

Sure, all that is true. I guess what I was trying to say is that it isn't something that suddenly would require large and immediate control inputs to keep from departing controlled flight.

RequestPidgeons 21st Jul 2015 10:00

Pitchlock
 
An interesting discussion, but it never goes as per the text book. I presume the pitchlock (any time after V1) is based on a total prop oil loss - PP1 and PP2 on steady? It doesn't happen. My experience was that PP2 will always find some oil and send it to the prop so that the pitchlock will ratchet to a finer blade angle with all the attendant results, higher rpm, less throttle to play with, etc. My course of action would be to stay as low and slow as AUW will allow and recover to departure airfield - hopefully visually. If it is unstable you can always pull the handle when landing is assured - it might feather, it might decouple but it is not going to put you in too adverse a situation. I doubt the gearbox will disintegrate on you in that short time-frame.

I presume that a crew in a sim are not trying to manually pitchlock the prop during takeoff? That strikes me as flightdeck overload and we all know what happens next.

Another option is the fuel chop and decouple. Sure the prop may go off guage but in the circuit/visual I believe even the average pilot should land safely.

The bigger issues are going IMC and LSALT for recovery, a high DA or having the event happen at ETP/PSR. All need to be thought through, the ADAK P-3 accident makes interesting reading. (ETA - Another thought is that you may not even know you have a problem until you turn the sync servo off!)

We pulled the handle when landing was assured and got a feather, but it did seem to take a bloody long time for the prop brake to take effect!


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