Auto Pilot Fails When Cold

[Bob Cook]

The autopilot, or any other piece of equipement, needs maintenance/ to be serviced once in a while. Probably the AP is the last to ever see a screwdriver or lubricant. These are electromechanical (electronic and mechanical) devices that should have servicing done and that includes the stec55 after awhile.

The 400b is a great autopilot and is not just a roll-rate device. You shouldn't throw out the baby with the bathwater just because it decides it needs some help.

If you cannot find some reliable shop to maintain it and you psych'd up to spend money then that is reason enough to change... I guess. The 55 is not the same level of sophistication as the 400 as it only acts AFTER a change in direction occurs.

maybe all the 737's built in the early 60's should get stec's as well. BTW the DC8 and 9s are still running around with their original APs.

mtsho (my not so humble opinion ) <G>

Kevin......

If the AP did NOT disengage then there is something seriously wrong as the power to the unit is fully disconnected when the front rocker switch (relay) is off or disconnected.

secondly, It you had to overide the controls with the AUTOPILOT OFF then for some strange reason the electromagnetic clutch did not disengage on the servo! This is rather strange. This does not make sense. The AP must not have been disengaged. The switch on the control colomn is in series with the rocker switch hold down coil (relay) so energizing this switch would drop ALL power to the AP. It does not make sense ... logically.

Bob