TM55-2840-251-23
Section X ENGINE TESTING (Continued)
1-95
GROUND TESTING OF ENGINE ON MOBILE
TRAILER ASSEMBLY (AVIM) (Cont)
5.c. (Cont)
(5) Enter curve with ambient temperature
and proceed vertically upward to intersection appropriate
field barometric pressure line. From this intersection,
proceed horizontally to left to read fuel flow in lbs/hr.
Record desired fuel flow.
(6) Enter curve with ambient temperature
and proceed vertically upward to intersect gas generator
data plate speed line. From this intersection, proceed
horizontally to left to read desired ratio (gas generator
speed data plate speed). Record desired ratio.
(7) Enter curve with ambient temperature
and proceed vertically upward to intersect interturbine
temperature line. From this intersection, proceed
horizontally to left to read interturbine temperature.
Record desired interturbine temperature.
d. Having determined values of these
parameters, proceed with engine performance check, as
follows:
(1) Perform pre-start check
(subparagraph 2).
(2) Accomplish satisfactory start
(subparagraph 3).
(3) Run engine at FLIGHT-IDLE to warm
up engine and to stabilize engine instruments.
(4) Set water brake hyronic lever to
control maximum output speed of 91% Ns (2000 rpm) and
power lever to torque setting previously determined from
engine performance curve.
(5) Compare observed fuel flow, gas
generator speed and interturbine temperature with values
previously recorded.
(6) Insure that values observed during
engine performance and data plate speed check are
within the following limits:
(a) 15 lbs/hr fuel flow.
(b) 2% maximum gas generator
speed data plate speed ratio. (Ratio = observed gas
generator speed data plate speed.)
(c) Interturbine temperature of +
30°C. If temperature is more than +30
C below target
temperature, check instrumentation.
NOTE
If observed values deviate from preceding limits, an
instrument or engine fault is indicated (refer to Section
VII, Troubleshooting).
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