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 2408-13-1. Operating time on
AVGAS is computed on the basis of quantity used and average consumption.
5-10. FUEL SYSTEM LIMITS.
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.
Takeoff torque may not be attainable during operations with AVGAS.
AVGAS operation is limited to 150 hours.
Crossfeed fuel will not be available from the side with an inoperative standby boost pump.
The use of AVGAS requires the standby boost pumps to be used during all operations above 15,000
Operation with JP-4 requires the use of standby pumps above 30,000 feet.
b. Fuel Management. Auxiliary tanks will not be illed for light unless the main tanks are full. Maximum allow-
able fuel imbalance is 300 lbs. Do not take off if fuel quantity gauges indicate in yellow arc (less than 265 lbs. of fuel
in each main tank). Crossfeed only during single engine operation.
JP-8 fuel per MIL-T-5624 has anti-icing additive per MIL-DTL-85470 blended in the fuel at the rein-
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 volume of fuel onboard, blend only enough additive for the un-
c. Fuel System Anti-Icing. Icing inhibitor conforming to MIL-DTL-85470 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. 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:
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 land-
ing gear retracted. If operation does not automatically terminate approximately 10 minutes after gear retraction,
turn off the BRAKE deice switch.