796 Empty Weight and CG Measurement While on Jackpoint Scales
100655-02
Determine the weight and balance condition of the
A5 by using the built-in jack points.
Instructions are for the Garmin 796 equipped aircraft.Applicable Aircraft Serial Numbers
All
Type of Maintenance
Line
Level of Certification
LSA-RM
Task Specific Training Required
No
Special Tools Required
Wing Jack Point Adapter—ICA009750
Parts Required
None
Aircraft System and Number
NA
Safety Equipment
As Needed
Consumables
None
Task Instructions
Verify the following conditions are met before performing the weight and CG measurement procedure:
• The airplane empty weight includes engine oil and coolant, unusable fuel, hydraulic brake fluid, and installed equipment for the aircraft.
• The airplane must be weighed and leveled in a level area. The weighing area should also be calm or indoors to prevent wind from affecting the readings.
• Check the calibration of the scales used to ensure accurate results.
• Check the oil dipstick to verify at least 3.17 quarts (three liters) of oil. Service as necessary.
• The difference between the max and the min marks is approximately 0.5 quarts (0.47 l).
• Retract flaps to the 0° position.
• Center all controls to the neutral, static position.
• Install removable side windows.
• Close and latch the canopy.
• Ensure all inspection covers and panels are installed.
• Brake fluid properly serviced.
• Bilge pump shall be run to ensure no water is in the aircraft.
• The wings shall be confirmed free of water.
• All control surfaces (ailerons, elevator, flaps) shall be checked and drained of water.
• The BRS Safety Pin for the Complete Aircraft Parachute shall be installed.
• The key shall be in the aircraft, installed in the ignition switch.
• All aircraft accessories are to be removed: Wind Deflectors, Tie Downs, Headsets, Removable Garmin, etc.
• POH must be in the aircraft, located in the co-pilot seatback pocket.
• Left and right hand rudder pedals must be in the most aft position.
• Verify all three (3) jacks are properly inserted in the jack points and are on the center of the scale (if used).
1. Install jack point adapters into the jack point receptacles on the underside of each wing.
2. Install load cells onto, or scales beneath, the aircraft jacks.
3. Verify that the scales are properly tared for an accurate reading.
4. Uninstall the co-pilot main cockpit floor board and place on the forward cockpit floor panel, approximately three inches forward, in order to read the bubble level.(Remove
Cockpit Floorboard) 5. Jack the aircraft clear of the ground, so that the bubble level on the right floor support indicates a level condition.
Note:
The three jack points are: 1) one under left wing, 2) one under right wing, and 3) one under the tail skid.
7. Complete the following worksheet.
8. Perform the calculations to obtain the required weight and balance information.
Verification Method
Fill out blank cells in table below.
Load Cell Position | Weight, Wt (lbf) | Arm, FS (in) | Moment, M=Wt x Arm (in-lb) |
|---|
Wing Left Jack Point | | 147.7 | |
Wing Right Jack Point | | 147.7 | |
Tail Jack Point | | 294.63 | |
Total | | | |
Calculate the FS location of the CG by dividing the total moment by the total weight.
Total Wt (from above)= ______lbs
FS Position of CG (Total M/Total Wt)=______ in
Verify readings and calculations and compare them with the POH records. Enter the new weight and balance information as a new baseline in the POH.
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