Point of order Mr. Chairman.
"The elevators normally move in the same direction and in equal amounts but there is a mechanism, the pitch uncoupling mechanism, which allows them to operate independently in the event one jams."
"By pushing the control columns in opposite directions, the Virgin pilots activated this mechanism and subjected the aircraft to stresses it was not designed to take."
This whole ATSB, CASA and ATR dialogue omits one essential element. The aircraft did not have a ‘control jam’. There was no cool headed decision made to ‘disengage’ the elevator channels and no requirement to do so. There was also no ‘auto pilot’ fault flagged. So, how did the ‘disconnect’ event which led to the aircraft being damaged occur? Was the AP actually fully disengaged before 'strong' manual input? Why did one crew member think pull ‘up’ was the cure and the other believe ‘push’ down a solution? Seems to me there are there serious questions which need to be answered before batting the ball back to ATR. There may well be other incidents where the crew became confused and inadvertently disconnected the elevator channels – but I’m blessed if I can find them. There are a couple of incidents where this has been deliberately done – without damage to the airframe. Perhaps there is a much simpler, untested, line if inquiry close to home. Seems to me the obvious questions should be eliminated first, before this esoteric discussion on the black art of test flying and certification is entered into – at great expense
If it walks like a duck - just saying..
Toot toot.
"The elevators normally move in the same direction and in equal amounts but there is a mechanism, the pitch uncoupling mechanism, which allows them to operate independently in the event one jams."
"By pushing the control columns in opposite directions, the Virgin pilots activated this mechanism and subjected the aircraft to stresses it was not designed to take."
This whole ATSB, CASA and ATR dialogue omits one essential element. The aircraft did not have a ‘control jam’. There was no cool headed decision made to ‘disengage’ the elevator channels and no requirement to do so. There was also no ‘auto pilot’ fault flagged. So, how did the ‘disconnect’ event which led to the aircraft being damaged occur? Was the AP actually fully disengaged before 'strong' manual input? Why did one crew member think pull ‘up’ was the cure and the other believe ‘push’ down a solution? Seems to me there are there serious questions which need to be answered before batting the ball back to ATR. There may well be other incidents where the crew became confused and inadvertently disconnected the elevator channels – but I’m blessed if I can find them. There are a couple of incidents where this has been deliberately done – without damage to the airframe. Perhaps there is a much simpler, untested, line if inquiry close to home. Seems to me the obvious questions should be eliminated first, before this esoteric discussion on the black art of test flying and certification is entered into – at great expense
If it walks like a duck - just saying..
Toot toot.