limpitakis
10th Jan 2015, 10:40
I wish to post a question concerning a mixed attitude of engine sensors regarding the kegworth accident.
I have seen the documentary on National Geographic and I wish you to clear something to me.
A catastrophic blade chip on the left engine of the plane changed the balance of the plane and launching a period of severe vibrations.
The engine sensors due to fan damage sensed lower fan speed and therefore increased fuel flow to that engine to compensate with the loss of speed but because of the damaged engine the vibration became far more violent.
The pilots by mistake shut down the good right engine by disengaging the autothottle and cut off power that engine.
Strangely the vibration stoped but why? The good engine was off and the left engine with the problem still run so why vibration stopped?
The documentary said that a side effect of setting autothrottle off and then cutting off the right engine had a similar effect to the left engine as well as is reduction of power that is .
Looking for answers I have found another documentary claiming that when disengaging autothrottle to off the throttles come to manual and because of this sensors within the bad left engine felt the low fan speed and reduced fuel flow in such a point that the engine could manage effortly.
That is why vibration stopped.
And here comes my question to any one that could clear this up to me.
Why engine sensors under autothrottle and under a catastrophilc fan blade failure compensate the low fan speed by increasing fuel flow to that engine as opposed to the same(?) sensors that react quite the opposite way by reducing fuel flow under manual throttle and same failure ?
The documentary stated that there might be mixed signals for the pilots.
I am not a professional pilot. I am a private pilot under 250 hours of flight as K1 with IFR rating and a very good understanding of jet's flight systems a legasy of mine achived be many years of studying and simulations.
I would appreciate if anyone could clear this foggy thing to me.
I have seen the documentary on National Geographic and I wish you to clear something to me.
A catastrophic blade chip on the left engine of the plane changed the balance of the plane and launching a period of severe vibrations.
The engine sensors due to fan damage sensed lower fan speed and therefore increased fuel flow to that engine to compensate with the loss of speed but because of the damaged engine the vibration became far more violent.
The pilots by mistake shut down the good right engine by disengaging the autothottle and cut off power that engine.
Strangely the vibration stoped but why? The good engine was off and the left engine with the problem still run so why vibration stopped?
The documentary said that a side effect of setting autothrottle off and then cutting off the right engine had a similar effect to the left engine as well as is reduction of power that is .
Looking for answers I have found another documentary claiming that when disengaging autothrottle to off the throttles come to manual and because of this sensors within the bad left engine felt the low fan speed and reduced fuel flow in such a point that the engine could manage effortly.
That is why vibration stopped.
And here comes my question to any one that could clear this up to me.
Why engine sensors under autothrottle and under a catastrophilc fan blade failure compensate the low fan speed by increasing fuel flow to that engine as opposed to the same(?) sensors that react quite the opposite way by reducing fuel flow under manual throttle and same failure ?
The documentary stated that there might be mixed signals for the pilots.
I am not a professional pilot. I am a private pilot under 250 hours of flight as K1 with IFR rating and a very good understanding of jet's flight systems a legasy of mine achived be many years of studying and simulations.
I would appreciate if anyone could clear this foggy thing to me.