Where is the datum located for a Cessna 172A model, with a serial number of 47743?

For the Cessna 172A model, the datum is established at the front face of the firewall. This refers to the reference point used for weight and balance calculations, where all measurements of distance from this point define the location of various components and equipment in the aircraft.

The selection of the front face of the firewall as the datum is practical because it provides a consistent and easily identifiable reference point for maintenance and operational activities. Measurements taken from the firewall to other components help in determining the center of gravity (CG) and assist in ensuring the aircraft is loaded within its weight limits.

Understanding the correct location of the datum is crucial for performing weight and balance calculations accurately. This ensures that the aircraft operates safely and complies with regulatory requirements.