Thanks OK465
Great stuff..why dont they teach us good stuff like that in the AFM!!
Correct Elev Low Pressure light.I think located on the centre fwd panel lefy of tge rydder and elev position indicator and below the Capt Marker beacons.Stab trim cut off on red.
Was the SP-150 AP on 727-200 certified to Cat2A or just Cat1?
Was there also an SP-100 fitted on Miss Piggy?
Originally Posted by
OK465
Miss Piggy had two square lights on the leftish (?) forward instrument panel, one red and one yellow, both of which were functional only with the A/P engaged (either SP-50 or SP-150).
The red one I believe was labeled SYS AB and was to warn if the hydraulic system in use by the A/P dropped below some threshold pressure (1/2 sys pressure or around 1500 psi I believe).
The light was deemed necessary because neither the block 50 nor 150 autopilots would disconnect automatically with hydraulic failure. The A/P would remain engaged electrically with all selected flight mode annunciations but would not be able to 'fly' the aircraft as such.
And the yellow one was the Stab Out of Trim light which is another story.
edit: As I recall now the red light was actually labelled 'Elevator Low Pressure' or something to that effect.