What would you do!! (MD Explorer)
Thread Starter
FNW - IIRC and surmising what little was made available about the crash, the crash occurred because a NOTAR fan blade torsion strap let go, this probably slowed the fan momentarily which shocked the NOTAR fan which caused the NOTAR drive shaft to shear just aft of the rotor brake. This meant the NOTAR system had failed (but he could still move the thruster, but there was nothing coming out of it). And again IIRC the broken drive shaft then smacked into the main fuel line for the No 2 engine which sheared it at the decking quick release self sealing couple - so he lost his No 2 engine as well.
I recall he carried out a slow speed/hover check at height and lost is and spiralled in to a crash.
Yes the Yaw Trim switch does allow pilot input to the VSCS - below 50 kts the aircraft yaws, above 50 kts it 'kicks' the ball. However I gave you a blind alley as it made no obvious change to the basic condition.
Some of my instruction must have been flawed - tut tut!! That is not what BJ said on the day!!
Regarding landing on hard or soft surfaces - IMCO go hard everytime and keep it hard if you can!! Soft has been proven to be asking for rollovers - the Hannover crash appears to have been caused when the aircraft unfortunately ran off the runway into the grass verge and rolled over. I believe the Knaus Explorer crash a few weeks earlier also rolled on grass.
Anyway - having just spent some time playing with a simulated right pedal jammed forward in-flight, I can confirm that the Yaw Trim had no impact on the problem. You must keep the IAS above 90 kts plus (if not more) to feel as if I had some control - and that was into a 36 kt wind!!
As regards trying to get it down - well thats another story
I recall he carried out a slow speed/hover check at height and lost is and spiralled in to a crash.
Yes the Yaw Trim switch does allow pilot input to the VSCS - below 50 kts the aircraft yaws, above 50 kts it 'kicks' the ball. However I gave you a blind alley as it made no obvious change to the basic condition.
Some of my instruction must have been flawed - tut tut!! That is not what BJ said on the day!!
Regarding landing on hard or soft surfaces - IMCO go hard everytime and keep it hard if you can!! Soft has been proven to be asking for rollovers - the Hannover crash appears to have been caused when the aircraft unfortunately ran off the runway into the grass verge and rolled over. I believe the Knaus Explorer crash a few weeks earlier also rolled on grass.
Anyway - having just spent some time playing with a simulated right pedal jammed forward in-flight, I can confirm that the Yaw Trim had no impact on the problem. You must keep the IAS above 90 kts plus (if not more) to feel as if I had some control - and that was into a 36 kt wind!!
As regards trying to get it down - well thats another story
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tbc ever considered playing around with the vscs switches ?
if you have airspeed the indicators will be hard over to the left (tail of the fin position) when you start lowering the lever they exit stage right and are then of less use keeping the nose left. How far right they go is my point because if you turn off the vscs the fins go to mid point on the indicator scale. So if they go past this point wouldn't it be better to turn them off for the last bit if the crash ? and at least have them doing something ?
if you have airspeed the indicators will be hard over to the left (tail of the fin position) when you start lowering the lever they exit stage right and are then of less use keeping the nose left. How far right they go is my point because if you turn off the vscs the fins go to mid point on the indicator scale. So if they go past this point wouldn't it be better to turn them off for the last bit if the crash ? and at least have them doing something ?
Thread Starter
Sulley - remember that the role of the VSCS is to 'schedule' to an optimum position as determined by the CLP etc. to drive the nose left in order to assist in overcoming torque reaction. Switching them off takes away a 'friend' in this instance I would suggest. You also cannot disable the VSCS right fin unless you disable the SAS, so you are making things possibly worse and not better.
Not convinced switching them off causes them to go to neutral - the indicator might but I'm not convinced the fins do.
Not convinced switching them off causes them to go to neutral - the indicator might but I'm not convinced the fins do.
Just to add my 2-penn'orth to the "hard vs soft" surface debate, if you have the choice between a runway and a taxiway, where the former has centreline lighting while the latter is unlit, then go for the taxiway. I've lost the photos of a 135 I ran-on in the Middle East; a chamfered 2 cm-tall runway light completely sheared one skid mount. We also found that the friction coefficients were very different - on the (very smooth) runway the aircraft carried on for over a hundred meters after a 25-kt touchdown, while on the taxiway it would stop 3-4 times more quickly.
Join Date: Sep 2007
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With all the experience you guys have I have now read and learned a little more and IF in future the need arises I will use CONCRETE and Taxiways at that.
Thank you all for the lessons you have learned,... and shared!
Whilst talking of experience, if any of you ever need to land in a ploughed field with skids, always land across the furrows(the lines) with wheels try never to land in a ploughed field! reason being the furrows of turned over soil hide voids that can be up to 24" or 2ft or 60 Cms deep going across will settle evenly with skids whichever way with wheels you sink!
Peter R-B
Thank you all for the lessons you have learned,... and shared!
Whilst talking of experience, if any of you ever need to land in a ploughed field with skids, always land across the furrows(the lines) with wheels try never to land in a ploughed field! reason being the furrows of turned over soil hide voids that can be up to 24" or 2ft or 60 Cms deep going across will settle evenly with skids whichever way with wheels you sink!
Peter R-B
