TM55-2840-251-23
Section X ENGINE TESTING (Continued)
1-94
GROUND TEST OF ENGINE
INSTALLED IN AIRCRAFT
(Cont)
8. (Cont)
f.
Checks after Accessory Replacement.
Perform ground checks as detailed in table (refer to table
following subparagraph 8.a.). The pneumatic portion of
fuel control system must be pressure tested whenever
leakage in any portion of system is suspected (refer to
Task 10-1).
9.
Idle Speed Adjustments.
a.
General. Since the gas generator speed at
minimum fuel flow varies with the barometric pressure as
shown on graph on opposite page, the engine will either
govern at the idle speed setting or run on the minimum fuel
flow stop, depending on the barometric pressure.
Moreover, in the barometric pressure range from 26.25 in.
Hg. to 28.65 in. Hg. since Ng at minimum fuel flow may
be anywhere between the limits shown on graph, it must
first be determined whether the engine is governing at idle
speed or running on minimum fuel flow before the idle
speed adjustment can be checked. Consequently, the
procedure for checking the idle speed adjustment depends
on barometric pressure.
b.
Barometric Pressure above 28.65 in. Hg. At
barometric pressures above 28.65 in. Hg., check idle
speed as follows:
(1)
Perform pre-start check (subparagraph
2).
GO TO NEXT PAGE
1-156
