POWER PLANT
18-16
For Training Purposes Only
May 03
P I L O T T R A I N I N G G U I D E
Start Sequence
Each engine has a set of START and STOP switch/lights on the ENGINE START/
IGNITION panel. When the engine START switch/light is pressed, the following
occurs:
•
left, right and isolation 10th-stage bleed air SOVs open
•
starter control valve on the associated engine opens to allow pressure from the
10th-stage manifold to engage the air turbine starter
•
when the starter control valve opens, a white light illuminates in the associated
START switch/light
•
at 55% N
2
rpm, the start control valve is de-energized and the ATS disengages.
The ATS is subject to the following starter engagement limits:
Starter Engagement Limitations
Table 18-1
Dry-Motoring
Dry-motoring is performed with ignition off and thrust levers at SHUTOFF.
Dry-motoring may be used for engine ground starts and engine airstarts.
START #
ENGAGEMENT TIME
COOLING PERIOD
1
2
3 & subsequent
30 seconds
30 seconds
30 seconds
none
none
5 minutes
DRY MOTORING #
ENGAGEMENT TIME
COOLING PERIOD
1
2 & subsequent
90 seconds
30 seconds
5 minutes
5 minutes
