- Type Certificate Data Sheet,
- Airworthiness Directives,
- Aircraft Flight Manual,
- or, Pilot’s Operating Handbook for older aircraft.
- The "Illustrated Parts Catalog", and the required "Equipment List" (describes what is required to be installed on the aircraft).
If the parts or product are not original equipment, have alterations been made? Alterations alter the Type Design.
For that product, or part to be airworthy the two conditions and all of the subfactors must be in agreement and in sync.
If one of the subfactors produces a negative answer or is out of sync then the corresponding condition fails. The product, or part is not considered airworthy.
If all of the subfactors produce a positive result and are in sync, then the corresponding condition passes.
The product, or part is considered to be airworthy.