Section IV. COLD WEATHER OPERATION
started and warms, the hydraulic fluid temperature should
4-1. Operating Temperature Limitations.
stabilize within normal operating limits.
a. Although MIL-H-83282 operates well under
4-2 Low Temperature Procedures.
normal temperatures, the viscosity of the fluid increases
as the temperature decreases. Therefore, the following
If, at any time during low temperature
minimum ambient operating temperatures have been
operation, initial flight control movement is sluggish or
established for the use of M I L-H-83282.
stiff, cycling of the flight controls may alleviate the
problem. Agitation of the fluid under pressure and radiant
heat from engines and transmissions may warm MIL-H-
83282 sufficiently to allow satisfactory operation of flight
b. If the temperature drops below the limitations
in para 4-1, and the procedures in para 42A are
See note below
unsuccessful, follow procedures given below:
(1) OH-58A Drain the MIL-H-83282
hydraulic fluid from the flight control system, and service
(2) AH-1G Drain the MIL-H-83282 hydraulic
fluid from hydraulic systems No. 1 and 2, and service
(3) UH-1 Drain the MIL-H-83282 hydraulic
CH-54B aircraft based in Alaska will
fluid from the hydraulic system(s) and service with MIL-H-
retain MIL-H-5606. All CONUS based
CH-54 aircraft will be converted to MIL-
(4) CH-47 Drain the MIL-H-83282 hydraulic
fluid from the hydraulic systems and components, and
The above temperatures are outside air temperatures
service with MIL-H-5606.
(OAT), measured at ground level prior to engine start.
(5) OV-1 Drain the MIL-H-83282 hydraulic
b. The above temperature limitations are based
fluid from the hydraulic system, and service with MIL-H-
on a cold soak of the hydraulic fluid at low temperatures.
Aircraft that are sheltered or preheated prior to engine
start should not have any problems with stiff or sluggish
(6) UH-60A See TM 55-1520-237-23-4.
flight controls. Unless the sheltered areas are at or below
the above temperatures in para 4-1, the viscosity of MIL-
H83282 will not create any difficulty. Once the aircraft is