TM 55-1510-221-10
5-13. ENGINE LIMITATIONS.
Observe the following limitations (table 5-1) during
operation of this aircraft equipped with two Pratt and
Whitney of Canada, Ltd. PT6A-41 engines. Each
column is a separate limitation. The limits presented do
not
necessarily occur simultaneously. Whenever
operating limits are exceeded, pilot should record the
value and duration of the condition encountered in the
aircraft log. Operation of the engines is monitored by
instruments, with the operating limits marked on the
face of each instrument.
CAUTION
Engine operation using only the engine driven
fuel pump without boost pump fuel pressure is
limited to 10 cumulative hours. All time in this
category shall be entered on DA Form 2408-13
for the attention of maintenance personnel.
CAUTION
Use of aviation gasoline is time-limited to 150
hours of operation during any Time-
Between-Overhaul (TBO) period. It may be
used in any quantity with primary or alternate
fuel.
5-14. OVERTEMPERATURE AND OVERSPEED
LIMlTATlONS.
a. Whenever the limiting temperatures are
exceeded and cannot be controlled by retarding the
power levers, the engine will be shut down and a
landing made as soon as possible.
b. During engine operation, the temperatures,
speeds and time limits listed in the Engine Operating
Speeds Limitations chart (table 5-1) must be observed.
When these limits are exceeded, the incident will be
entered as an engine discrepancy in the appropriate
maintenance forms. It is particularly important to record
the amount and duration of over temperature and/or
overspeed.
c.
Continuous engine operation above 725ºC will
reduce engine life.
5-6
5-15. POWER DEFlNlTlONS FOR ENGINE
OPERATIONS.
The following definitions describe the engine
power ratings.
a. Takeoff Power. The maximum power avail-
able, limited to periods of five minutes duration.
b. Maximum Continuous Power. The highest
power rating not limited by time. Use of this rating is
intended for emergency situations at the discretion of
the pilot.
5-16. GENERATOR LlMlTS.
Maximum generator load is limited to 100% for
flight and variable during ground operations. Observe
the limits shown in Table 5-2 during ground operation.
Section ill. POWER LlMlTS
