Weighing the aircraft:
Weighing aircraft with accurately calibrated scales is the only sure method of obtaining an accurate empty weight and CG location.
All scales for aviation use, manuel or electronic, must be protected when stored, shipped, and they must be checked periodically for accuracy.
The maximum period between calibration checks is twelve months, this period can be reduced by any airworthiness authority dependent on the condition of use.
In general, weight procedures may vary with the aircraft and types of weight equipment employed.
The weight procedure contained in the manufacturer's maintenance manual should be followed for each particular aircraft.
Scale preparation.
Mechanical and electronic scales shall be inspected prior to use and set to zero.
This is done by adding and removing a weight, then rechecking for zero. This proces should be repeated until a steady zero setting is obtained.
The scales should be located in the same environment in which they are to be used and allowed to come up to temperature at least 2 hours prior to use.
Weigh clean aircraft inside hangar:
The aircraft should be weighed inside a hangar where wind, hangar heaters and or ventilation cannot blow over the surface and cause fluctuating or false scale readings.
The aircraft should be clean inside and outside, with special attention to ensure that no water, debris is trapped inside several area's.
The outside of the aircraft should be free as possible of mud and dirt.
Equipment List:
You must use only the correct equipment list that belongs to the aircraft yor going to weigh.
All of the required equipment must be properly installed, and ther should be no equipment installed that is not included in the equipment list.
If such equipment is installed, the weight and balance record must be corrected to indicate it.
Ballast:
All required permanent ballasts must be properly secured in place.
All temporary ballasts must be removed before the weighing proces.
Standard weights:
Standard weights are established weights for numerous items involved in weight and balance computations.
These weights should not be used if actual weights are available.