Flight inspection of NAVAIDs involves the use of specific flight test aircraft, which are equipped to measure compliance of the navigation aid signals-in-space with ICAO standards. Due to the flexibility of PBN to create routes or procedures in areas where a particular ground facility has normally not been flight inspected, it may be necessary to perform dedicated flights. Of primary interest is the actual coverage of the NAVAID infrastructure required to support the flight procedures designed by the flight procedure designer. Depending on the avionics capabilities of the test aircraft, flight inspection and flight validation activities may be combined. The amount of flight inspection required is determined by the infrastructure assessment conducted as part of activity 6, and is part of the validation process.
The Manual on Testing of Radio NAVAIDs (ICAO Doc. 8071) provides general guidance on the extent of testing and inspection normally carried out to ensure that radio navigation systems meet the SARPs in Annex 10 – Aeronautical Telecommunications, Volume I. ICAO Doc 8071 consists of three volumes, two directly applicable to navigation; Volume I, updated in 2018, addresses the testing of ground-based radio navigation systems and Volume II addresses the testing of satellite-based radio navigation systems
To what extent a Flight Inspection needs to be carried out is normally determined in the validation process.