Engine Start Speed

[GusRodrigues]

IXEG 737 V1.5

 

APU Bleed pressure is above 40 psi. at +4,000 ft of pressure altitude. Engine won't spool up to 25% N2, max motoring was around 21% after 25seconds. After fuel-levers are on idle, the engine accelerate rapidly to idle Speed (10s or less). Engine start finishes as expected, but total start time under 30s.

 

how to reproduce:

Set yourself in KSLC, ISA Day. APU and Eng Bleeds ON, Packs OFF, Isolation Valve Open (APU providing bleed to #1 and #2 Bleeds, confirmed in the pressure indicator).

Start #2 Engine

Max motoring should be closer to 30% with an APU Bleed above 30 PSI, but max atteignable motoring speed was 21.5% N2.

At max motoring, engine fuel-levers to IDLE, engine will rapidly spool up to IDLE (61% N2).

[Litjan]

Thanks for the report, will tune high-alt starter behavior and we will look at a way to override the default X-Plane startup spool speed.