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Old 29th May 2011, 12:53
  #550 (permalink)  
rubberband2
 
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From post #290 on 28 May 11 ....
BEA Report – The trimmable horizontal stabilizer (THS) passed from 3 to 13 degrees nose-up in about 1 minute and remained in the latter position until the end of the flight.

The last recorded values were a pitch attitude of 16.2 degrees nose-up, a roll angle of 5.3 degrees left and a vertical speed of -10,912 ft/min.


Where is the BEA quoted (THS) trim nose-up angle measured?

Is it an internal computed value displayed on EICAS?

Is it 13.2º on the cockpit pedestal trim wheels?

Is it 13.2º as shown on some aircraft where the horizontal stabiliser (tailplane) leading edge fairing meets the vertical fin?

Or ..... ?
There were no replies to the above post so let the question be posed in a different form:

The iconic book 'Handling The Big Jets' by D P Davies was published in 1967 and revised in the 1977 edition. It has several pages of useful info and charts on pages 115 - 128 under the paragraph headed 'The Super Stall'.

Moreover, on page 122 there is an excellent diagram showing the 'lack of relationship between attitude and incidence'.

The recent BEA report 2 recorded the trimmable horizontal stabilizer (THS) at a 13 degrees nose-up value. Therefore the leading edge of the THS (depending on where measurements are taken) will be at a negative below horizontal datum angle of 13º).

Surely this huge displacement of 13º would be shown on the centre console manual trim wheels?

The trim wheels are visible to all 3 pilots on the flight deck. Also a true 13º is likely to have a much expanded arc on the trim wheel of perhaps double the true arc value to visually indicate this extreme displacement.
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