TM 55-1510-222-10
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 2408-13.
Operating
time
on
AVGAS
is
computed on the basis of quantity
used and average consumption.
a.
Operating Limits.
(1) Operation with FUEL PRESS light on is
limited to 10 hours. Log time (duration) FUEL PRESS
light is illuminated on DA Form 2408-13.
(2) Crossfeed of AVGAS to an engine with a
failed engine boost pump is not authorized.
(3) Takeoff torque may not be attainable during
operations with AVGAS.
(4) AVGAS operation is limited to 150 hours.
(5) 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.
(6) Crossfeed fuel will not be available from the
side with an inoperative standby boost pump.
(7) The use of AVGAS requires the standby
boost pumps to be used during all operations above
15,000 feet.
(8) Operation with JP4 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 200 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 minimum of
0.060% and a maximum of 0.15%.
• JP-4 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 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 the brake deice switch OFF.
(3) Maintain
85%
N.
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
5-5
