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Old 29th May 2011, 12:58
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Graybeard
 
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Is it Speed Over the Ground, or Velocity?

cogsim:
The last recorded values were a vertical speed of -10,912 ft/min, a ground speed of 107 kt, pitch attitude of 16.2 degrees nose-up, roll angle of 5.3 degrees left and a magnetic heading of 270 degrees.

ground speed: 107 kt
vertical speed: -10,912 ft/min = -107 kt

Coincidence? Maybe.
What speed does a skydiver's GPS read? It subtracts where you were from where you are to come up with Speed, so probably reads zero.

The Inertial Reference Units in expensive aircraft integrate accelerations in 3 dimensions to calculate Velocity. It's been a long time since I've been intimate with inertials, but seems to me the ground speed reported by BEA was in reality Vertical Velocity.

IOW, the plane dropped like a skydiver.

Good catch, cogsim.

Last edited by Graybeard; 29th May 2011 at 13:01. Reason: Change speed to velocity
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