Part 21 – Certification Procedures for Products and Parts

What are the two main types of airworthiness certificates under § 21.175?

Standard and Special airworthiness certificates.

What categories of aircraft receive a Standard Airworthiness Certificate?

Normal, Acrobatic, Commuter, Transport, Manned Free Balloons, and special classes designated by the FAA.

What categories fall under Special Airworthiness Certificates?

Primary, Restricted, Limited, Light-Sport, Provisional, Experimental, and Special Flight Permits.

What is the difference between Standard and Special airworthiness certificates?

Standard = fully certificated aircraft; Special = for non-standard or limited-use operations.

Under § 21.181, how long is a standard airworthiness certificate valid?

Indefinitely, as long as the aircraft is maintained per Parts 43 & 91 and remains U.S. registered.

What makes a standard airworthiness certificate invalid?

Improper maintenance, loss of U.S. registration, unsafe condition, or FAA action (suspension, revocation, termination).

Who can request inspection or surrender of an airworthiness certificate?

The FAA.

What is a Special Flight Permit under § 21.197?

Permission to fly an aircraft that does not currently meet airworthiness standards but is safe for flight.

When might you need a Special Flight Permit?

To fly to a maintenance location, for delivery, export, flight testing, or moving away from danger.

Who issues a Special Flight Permit?

The FAA

What condition must be true for a Special Flight Permit to be issued?

The aircraft must be safe for the intended flight, often confirmed by a mechanic.