Originally Posted by alexban
While in heavy traffic,or sometimes in bad weather,we select ap on as low as 500'. The ap engages in LVL CHG ,not in VS. At least on the 737.
Alex,
The version of the 733/4/5 FCTM I have suggests the AP is only FAA certified to allow engagement on TO above 1000 AGL.
Has that changed? Or its just that your SOP's allow that?
I've never tried engaging the AP before clean up (although I suppose on a Noise Abatement departure it is quite legitimate) but I imagine the annunciations go from ARM or THR HLD/TOGA to MCP SPD/LVL CHG with the speed window opening at V2 + 20?
A reduction in climb thrust is prevented if LVL CHG is selected (or AP engaged) until 2 1/2 mins has elapsed from TO unless N1 is selected, VNAV engaged or you ALT ACQ/ALT HLD.
Anything else would make a mockery of the performance...
Is that correct?