Airplane Flight Manual
Page 19
FAA Approved
Revision A3: Apr 26, 2007
Section - 6
WEIGHT & BALANCE
GENERAL WEIGHING INSTRUCTIONS
Periodic weighing of the airplane may be required to keep the Basic Empty Weight current, with
the frequency of weighing determined by the operator. All changes to the airplane affecting
weight and/or balance are the responsibility of the operator.
Airplane weighing should be done in an enclosed, draft free hangar. The airplane exterior
should be clean and dry. All equipment that is a part of the Basic Empty Weight should be
installed in the proper locations. All loose equipment such as protective covers, tools, galley
contents, etc. should be removed. Engine oil, hydraulic fluid, de-icing fluid, toilet precharge and
oxygen should be full. Galley and lavatory liquids should be drained. Fuel should be drained
and the drain ports and the water drains sumped. Ensure that the weighing equipment
certification is current and that the scales read "0" with no load applied.
The airplane may be weighed on jack points, wheels or wheel change jacks. For each method,
the airplane must be in a level attitude. This is determined by placing a leveling bar, RAC Part
No. 25-Y-23A or equivalent, and an inclinometer or spirit level on the leveling bolts just inboard
of the lower seat track at FS 309.35 and FS 371.55. Be sure to remove the leveling equipment
before recording the scale readings.
Refer to Figures 6.6 and 6.7, Weighing Points and the Basic Empty Weight & Balance Form.
Jack Point Weighing
Place the jacks and weighing units under the two main jack points at 4.12 ft (1.256 m) forward
(-) of the cg datum, and the tail jack point at 15.65 ft (4.770 m) aft (+) of the cg datum. Operate
the jacks in unison to keep the airplane level as it is raised and until the wheels just clear the
floor.
Ensure that the airplane is level and record the scale readings. If the jacks are placed on
platform scales, be sure to remove the weight of the jacks from the scale readings. Operate the
jacks in unison to keep the airplane level as it is lowered. Remove the jacks from the platform
scales if used, and ensure that the scale readings have returned to "0".
Wheel Weighing
Place the airplane on the scales in a level attitude and record the scale readings. The wheel
locations (axle centerlines) must be determined by measurement with the airplane in a level
attitude. Drop a plumb bob from the fuselage reference point located below the right engine
pylon at 11.00 ft (3.353 m) aft (+) of the cg datum. Measure from this point to a string stretched
between the Left and Right inboard main wheel axle centerlines (Figure 6.7, Dimension B) and
then from the string to the nose wheel axle centerline Left and Right sides - use the average
of the two sides (Figure 6.7, Dimension A). All measurements must be taken with the tape level
and parallel to the fuselage centerline.
The inboard main wheel axle centerline is 0.058 ft (0.018 m) aft of the main gear bogie
centerline, which is the true weight reaction point. Therefore, 0.058 ft (0.018 m) must be added
to Dimension B (Figure 6.7) and subtracted from the Dimension A (Figure 6.7) average
measurement. The main wheels should be approximately at 2.8 ft (0.85 m) and the nose
wheels at -18.4 ft (-5.61 m). Remove the airplane from the scales and ensure that the scale
readings have returned to "0".
For Training Purposes Only
