20 minute time groupings. It is suggested the cycle
rate should not exceed 10 cycles equally spaced in
1 hour. This rate is to keep the power pack motor
operations within an intermittent duty class.
b. Brake Deice Limitations. The following
limitations apply to the brake deice system.
(1) The brake deice system shall not be
operated at ambient temperatures above 15 °C.
(2) The brake deice system shall not be
operated longer than 10 minutes, one timer cycle, with
the landing gear retracted. If operation does not
automatically terminate approximately 10 minutes after
gear retraction, turn BRAKE DEICE switch off.
(3) Maintain 85% N1 or higher during
simultaneous operation of the brake deice and surface
deice systems. If adequate pneumatic pressure
cannot be provided for simultaneous operation of the
brake deice and surface deice systems, turn BRAKE
DEICE switch off.
(4) BRAKE DEICE switch shall be turned off
during single engine operation, in order to maintain an
adequate supply of systems pneumatic bleed air.
The pneumatic surface deice system shall not be
operated when ambient temperatures are below
-40 C. Permanent damage to the deice boots can
Section III. POWER LIMITS
5-14. ENGINE LIMITATIONS.
Operation of the engines is monitored by
instruments, with the operating limits marked on the
face of each instrument.
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 2408-13-1 for the attention of
Use of aviation gasoline is time limited to
150 hours of operation during any Time
BetweenOverhaul (TBO) period. It may be
used in any quantity with primary or
Aviation gasoline (AVGAS) contains a form
of lead that has an accumulative adverse
effect on gas turbine engines. The lowest
octane AVGAS available (less lead content)
should be used. If any AVGAS is used the
total operating time must be entered on DA
a. Whenever limiting temperatures, listed in the
Engine Operating Limitations, Table 5-1, are exceeded
and cannot be controlled by retarding the power
levers, shutdown the engine and land as soon as
b. During engine starting, the temperatures and
time limits, listed in the Engine Operating Limitations,
Table 51, 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 overtemperature.
c. Whenever the prescribed engine overspeed
limit or engine RPM operating limit is exceeded, the
incident must be reported as an engine discrepancy in
the appropriate maintenance forms. It is particularly
important to record the maximum percent of RPM
registered by the tachometer, and the duration of
d. Continued engine operation above 725 °C
C D (770 °C T ), TGT will reduce engine life.