TM 55-1520-240-23-11
SECTION III
G-12. Aircraft Weighings. Aircraft must be weighed.
a.
Periodically as required by pertinent directives. (Refer to AR 95-16.)
b.
When major modifications or repairs are made.
c.
When the pilot reports unsatisfactory flight characteristics (nose or tail heaviness).
d.
When the basic weight data is suspected to be in error. The basic weight and CG location obtained from
a weighing can be only as accurate as the scale equipment employed. Scales must be calibrated as
required by existing directives.
G-13. Preliminary weighing instructions. Preliminary weighing instructions are as follows:
a.
Assemble necessary equipment, including scales, hoisting equipment, jacks, cribbing, leveling bars, level,
measuring tape, plumb bob, and string.
b.
Remove dirt, grease, moisture, etc., from aircraft.
c.
Drain fuel from all tanks, using tank drains, with aircraft in its normal attitude on ground. If impracticable to
drain due to fire hazard or local regulations, fill to capacity. Since weight of fuel varies with temperature,
determine actual weight per gallon by use of a hydrometer. Multiply by gallons capacity, obtained from
loading data sheets, for total fuel weight. Never weigh with partially filled tanks.
If the helicopter is to be weighed with full fuel tanks, the helicopter must be weighed using the 4
point method.
d.
Fill oil tanks to operating capacity.
e.
Fill hydraulic systems and reservoirs to normal levels.
f.
Inflate or deflate main landing gear oleo struts to normal extension or to anticipated desired height. It may
be helpful for leveling and in jacking to lash a rope around the torque arm of the forward landing gear and
apply the aft shock strut static lock so that the strut will not extend when the aircraft is lifted.
g.
Conduct an inventory of fixed operating equipment actually installed in aircraft. This shall be accomplished
on the Basic Weight Check List, DD Form 365-1.
NOTE
A basic weight without the equivalent inventory is of no value to the activity receiving the aircraft.
h.
Release brakes before aircraft is placed on scales to reduce possibility of side loads and thrusts on
scales which may give erroneous weighing results.
i.
Jacking the aircraft shall be accomplished in accordance with requirements of Chapter 1 of the -23
maintenance manual. Refer to Figure G-6 for location of jack pads and weight restrictions.
NOTE
The aircraft must be weighed in a closed hangar.
G-14. Weighing equipment. Weighing aircraft with accurately calibrated scales is the only sure method of
obtaining an accurate basic weight and CG location. Reference is made to TM 55-1500-342-23 for use of the
electronic weighing kit. Additional instruction for aircraft weighing that is not contained in TM 55-1500-342-23 for
the individual aircraft shall be covered in this section.
G-41
