TM 1-1510-224-10
5-10. FUEL SYSTEM LIMITS.
NOTE
Aviation gasoline (AVGAS) contains
a
form
of
lead
which
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 Form 240813-1.
Operating
time
on
AVGAS
is
computed on the basis of quantity
used and average consumption.
a.
Operating Limits.
(1)
Operation with FUEL PRESS annunciator
light illuminated is limited to 10 hours.
Log time (duration) FUEL PRESS light is illuminated
on DA Form 2408-13-1.
(2)
Crossfeed of AVGAS to an engine with a
failed engine-driven boost pump is not authorized.
Crossfeed of AVGAS to an engine with a failed engine-
driven boost pump will result in less than minimum fuel
pressure to the high pressure pump on that side.
(3)
Takeoff torque may not be attainable
during operations with AVGAS.
(4)
AVGAS operation is limited to 150 hours.
(5)
Crossfeed fuel will not be available from
the side with an inoperative standby boost pump.
(6)
The use of AVGAS requires the standby
boost pumps to be used during all operations above
15,000 feet.
(7)
Operation with JP-4 requires the use of
standby pumps above 30,000 feet.
b.
Fuel Management. Auxiliary tanks will not be
filled for flight unless the main tanks are full. Maximum
allowable fuel imbalance is 300 lbs. Do not take off if
fuel quantity gages indicate in yellow arc (less than 265
lbs. of fuel in each main tank). Crossfeed only during
single engine operation.
CAUTION
JP-8 fuel per MIL-T-5624 has anti-
icing
additive
per
MIL-I-27686
blended in the fuel at the refinery and
no further treatment is necessary.
Some fuel suppliers blend in anti-
icing additive, in their storage tanks.
Prior to refueling, check with the fuel
supplier to determine if fuel has been
blended.
To
assure
proper
concentration by volume of fuel on
board, blend only enough additive for
the unblended fuel.
c.
Fuel
System
Anti-Icing.
Icing
inhibitor
conforming to MIL-I-27686 will be added to commercial
fuel, not containing an icing inhibitor, during fueling
operations, regardless of ambient temperatures. The
additive provides anti-icing protection and also functions
as a biocide to kill microbiological growth in the aircraft
fuel system.
5-11.
LANDING GEAR CYCLING AND BRAKE
DEICE LIMITATIONS.
a.
Hydraulic Landing Gear. While conducting
training operations, the landing gear cyclic rate shall not
exceed 5 complete (extension and retraction) cycles
equally spaced in a 20 minute period, without allowing a
10 to 15 minute interval between the 20 minute time
groupings. It is suggested the cycle rate should not
exceed 10 cycles equal spaced in one (1) hour. This
rate is to keep the power pack motor operations within
an intermittent duty class.
b.
Brake Deice. The following limitations apply to
the brake deice system:
(1)
The brake deice system shall not be
operated at ambient temperatures above 15C.
(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 the 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 off the brake
deice system.
(4)
The brake deice system shall be turned off
during single engine operation, in order to maintain an
adequate supply of systems pneumatic bleed air.
5-12. PITOT HEAT LIMITATIONS.
a.
Pitot heat should not be used for more than 15
minutes while the aircraft is on the ground.
5-7
