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View Full Version : 737/400 controls question


cfmblast
17th Dec 1999, 16:27
Anyone that knows if we have rudder and aileron trim with a loss of all generators?
(please give info for power sources if possible).
Thank you!!!

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cfm blast

Pikvanman
23rd Dec 1999, 01:46
Got to check the books on that one.Hang on.

growler
24th Dec 1999, 01:56
My understanding of the 737-300 WDM says that both aileron and rudder trim control is provided by 115V A.C TXFR Bus1. This bus is NOT powered when down to battery/standby power.

cfmblast
25th Dec 1999, 03:37
Thank you growler!!
You just added a little but very valuable piece of info in the expanding world of knowledge!!! :)

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cfm blast

HighSpeed
25th Dec 1999, 11:25
since you guys are at it, could you kindly enlighten me if there will be rudder/aileron trim during manual reversion ? if yes, is it by mechanical linkages ? i noticed on grd with hdy depress moving the rudder/aileron trim only moved the pedals/wheels a fraction. does it mean that will happen too, in flight without hyd ??

thanks

HS

cfmblast
25th Dec 1999, 15:32
HighSpeed,
Rudder trim is for sure available as the rudder during man rev uses hyd with a separate rudder PCU (STBY RUD PCU).
As for the ailerons,i'm pretty sure they also have the trim ability!!!
Merry X-mas!!!!! :)

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cfm blast

growler
29th Dec 1999, 12:35
Applying trim inputs with Hyds 'OFF' will cause movement of the relevant surface. The trim actuators are attached to the 'Feel and Centering Units'. These in turn are directly attached to the controlcables and bell cranks. Therefore any movement of the actuator will result in movement of the surface.