PPRuNe Forums - View Single Post - Deselect speed (autothrottle) on B737
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Old 8th May 2007, 10:51
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BOAC
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Telstar - I think that accident is not pertinent to this discussion as it was a manual approach flown with auto-throttle engaged? It does, however, re-inforce the Boeing advice on not doing that!

Certainly BA (on the 737) - and current airline - 'teach' the 'armed' mode for manual landings. In both it is pretty well an 'SOP', if unwritten. In BA it was even 'encouraged' for the last few hundred feet of a s/engine approach to give a/throttle g/a (and very useful that was in the sim where you always go round ) - despite the Boeing FCTM 'restriction'.

I have seen the disruption of a landing in 'armed' (from the RHS). The main problem will occur in that rare event when the HP flies the correct approach speed (instead of around +15 ), and particularly at F40 where 1.3Vs can be v v close to Vref+5. IF the HP then starts a flare a bit early (ie above 27'RA) and the a/t kicks in as designed as the speed (correctly) washes off towards Vref-5, you can get the traditional 'fly-past' until it is sorted.

Personally my preference is for a/t off for manual flying and push hand forward for g/a.
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