Allan
12th Apr 2005, 12:23
Hi.
Anyone out there who can enlighten me as to why the "speed trim fail" light is on when the IRS' are not aligned??
Kind regards
Valve Kilmer
12th Apr 2005, 13:03
The speed trim system(STS) monitors different inputs such as airspeed, vertical speed, stabilizer position and thrustlever position, in order to augment the speed stability of the aircraft by commanding the stabilizer in different directions. As long as the ADIRUs(air data/inertial reference units) are not fully aligned, a few input will be considered unreliable by the Flight Control Computers(FCCs), thereby causing the STS to ”fail”.
Rgrds VK