TM 1-1510-223-10
5-6 Change 3
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 JP4 requires the use of stand-
by pumps above 30,000 feet.
b. Fuel Management. Auxiliary tanks will not be filled
for flight unless the main tanks are full. Maximum allow-
able 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
Anti-icing additive must be properly blended with
the fuel to avoid deterioration of the fuel cell. The
additive concentration by volume shall be a mini-
mum of 0.060% and a maximum of 0.15%.
JP-8 fuel per MIL-T-83133 has anti-icing additive
per MIL-I-27686 blended in the fuel at the refin-
ery 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 vol-
ume 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 con-
taining an icing inhibitor, during fueling operations, re-
gardless 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 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 termi-
nate approximately 10 minutes after gear retraction, turn
the brake deice switch OFF.
(3) Maintain 85% N1 or higher during simulta-
neous operation of the brake deice and surface deice
systems. If adequate pneumatic pressure cannot be pro-
vided 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.
