Weighing Procedures
Earlier in this series, the necessary steps to prepare aircraft and equipment prior to a weighing were addressed. Up to this point, the aircraft has been properly defueled and configured for its weight and CG check.
If using additional jack pads to protect the airframe jack point with Top of Jack/Axle Jack, their weight and moment (weight times the arm) must be recorded in order to delete them from the total weight and moment shown on the scales. To eliminate any side loading, aircraft jacking must be done as level as possible. Do not be in a hurry in either lifting or lowering; down jacking also should be done slowly and as level as possible for safety. Remember to exercise the load cells to the full weight of the aircraft and then zero your scales prior to the first actual weigh.
“Given proper equipment and staff training, correct weighing procedures will produce the most accurate and repeatable weights possible.”– Patrick McIntyre, Director of Weight & Balance Training
When using platform scales, a tow vehicle is the preferred method of getting the aircraft up onto your scales, which is much safer than pushing the aircraft. Once the scales are exercised to the full weight of the aircraft, zero your scales prior to your first actual weigh. If you feel you need to chock your aircraft once up on your scales, place the chocks on the scales first and then re-zero your scales. This makes your chocks invisible to the weight shown (and yes, once the chocks are removed you will display a negative number, which is to be expected).
Now just a bit of math to determine your total weight and moment…then calculate your center of gravity. Software or apps are available to record the information, perform the calculations, and output the data for these platform scale and jack weighing techniques.
Find more information on Certified Weight & Balance Training
Find more information on Aircraft Scales & Load Cells
Intercomp offers both Military and Civilian focused training for military staff, engineers, contractors, and FAA A&P licensed civilians. Courses are led by instructors benefitting from three decades of weighing experience in both military and commercial venues. Leveraging a background of weighing hundreds of aircraft, classroom attendees have access to a knowledge base in equipment and operations that is unmatched within the industry in quality, depth, and experience.
