autothrottle
18th Nov 2000, 20:49
Just a quick question for all you B737 crews.Unfortunately I do not fly B737,but on a recent jump seat trip we did discuss procedures to minimise the risks should a hardover take place.
Would anyone be able to give me some Idea of their procedures once below 210kts and when flap is lowered.I am interested in wether you add any extra safety margin for your refernce speeds or lower flap slightly later.As I say I am not a B737 pilot but fly professionally in a/c below 5700kgs,so my apologies if this seems an odd question.
Cheers
AUTOTHROTTLE
Contrails
19th Nov 2000, 05:53
There's a recommendation until a redesigned rudder power control unit, installation of a new yaw damper system and a rudder pressure reducer. For flap setting of Up, 1, 5 and 10, pilots must increase block speeds by at least 10kt. Block speeds are the maneuvering speeds recommended by Boeing. They are approach speeds for a specific flap setting for a correponding range of weights. In case of a full roll control from the ailerons and spoilers to counteract any inadvertent rudder input speed must be above "crossover" speed. Below that speed roll induced by the rudder can exceed the lateral control authority.
After some analysis a new block speeds were recommended:
Weight up to 53,070kgs - Flaps up 220kt, Flaps 1 200kt, Flaps 5 190kt and Flaps 10 170kt.
Above 53,070kgs up to 62,823kgs - Flaps up 230kt, Flaps 1 210kt, Flaps 5 200kt and Flaps 10 180kt.
Above 62,823kgs - Flaps up 240kt, Flaps 1 220kt, Flaps 5 210kt and Flaps 10 190kt.
Note: Increasing block speeds during takeoff is not required. Airspeeds required by non-normal procedures must be followed instead of the revised block speeds. B737NG's are not affected by this new block speeds because they are equipped with a rudder limiter system.
autothrottle
19th Nov 2000, 16:12
Cheers Contrail,
Very interesting,thanks for the info!
AUTOTHROTTLE