Inspection Authorization (IA)

The Inspection Authorization is issued by the FAA under 14 CFR Part 65 Subpart D, §65.91, and represents the highest level of certification available to an aviation maintenance technician short of an airline's Airworthiness Release authority. An IA holder has the authority to perform annual inspections of aircraft in accordance with §91.409(a) and return the aircraft to service after that inspection; to perform and approve progressive inspections under §91.409(d) as part of a continuous inspection program; and to approve the data used for major repairs and major alterations, signing FAA Form 337 as the approving mechanic to authorize the altered or repaired aircraft for return to service. The Form 337 authority is particularly significant — it is the mechanism by which non-standard, one-off modifications to certificated aircraft are legally documented and approved.

Eligibility requirements under §65.91 are more demanding than those for the underlying A&P certificate. The applicant must: (1) hold a currently valid Airframe and Powerplant certificate (both ratings are mandatory — a single-rating mechanic is not eligible); (2) have held that certificate for at least 3 years; (3) have been actively engaged in maintenance for at least the 2 years immediately preceding the application; (4) hold a fixed-base operator's certificate or be employed by a repair station, air carrier, or commercial operator, OR show that the IA will be used to benefit a school or other institution; and (5) pass a comprehensive written test (FAA knowledge test code IA) at an FAA-approved testing center with a minimum passing score of 70%. The written test covers all types of inspections, the applicable regulations, and required documentation.

The IA is not a permanent authorization. Under §65.93, it expires on March 31 of each odd-numbered year (a two-year renewal cycle). Renewal requires either passing the IA written test again OR presenting evidence of at least 8 hours of inspection-related training completed within the preceding 90 days from an FAA-approved source, plus documentation of having performed at least one annual inspection within the previous 12 months. The 12-month active use requirement means that an IA who has not performed any annual inspections during the preceding year cannot renew without re-testing — a provision designed to ensure that IA holders remain current in practice, not just in certification.

The distinction between what an A&P can do and what an IA adds is the central practical dividing line in general aviation maintenance. An A&P without an IA can perform a 100-hour inspection (required under §91.409(b) for aircraft operated for hire, including flight instruction) and sign the aircraft's maintenance record to return it to service after that inspection. The 100-hour inspection uses the same checklist as an annual inspection — the difference is purely in who can approve the return to service and what the legal effect of the inspection is. Only an IA can perform an annual inspection and return the aircraft to service; the annual inspection is what resets the 12-calendar-month clock that §91.409(a) imposes on every certificated aircraft regardless of hours flown.

Major repairs and major alterations present a separate IA function. 14 CFR Part 43 Appendix A categorizes repairs and alterations as major or minor. A major repair or alteration to an aircraft structure, propeller, or engine requires FAA approval — either through an approved manufacturer data package, an STC, or an A&P with IA signing FAA Form 337. For field approvals (repairs not covered by existing approved data), the IA submits the Form 337 with supporting engineering data to the local FSDO for final approval. This process is the primary mechanism for one-off repairs after damage incidents and is frequently encountered by flight schools after training aircraft sustain prop strikes, hard landings, or ground handling damage.

For flight schools, the IA is the single most important credential in the maintenance chain for general aviation training fleets. Without a contracted or employed IA, a school's aircraft cannot receive annual inspections — a regulatory hard stop that would ground the entire fleet. The practical scheduling reality is that IAs who are not employed full-time by the school are often in high demand, particularly as general aviation maintenance technician retirements continue to outpace new entrants. Schools that rely on a single external IA face existential scheduling risk: if that IA becomes unavailable during the month an aircraft's annual is due, the aircraft cannot fly until the inspection is completed by a qualified IA.

The interaction between the 100-hour inspection (which any A&P can perform) and the annual inspection (which requires an IA) creates a compliance tracking challenge when aircraft are flying significant hours per month. A training aircraft that accumulates 80 hours per month will need both 100-hour inspections (every 5–6 weeks) and annual inspections (once per calendar year). Because the 100-hour and annual clocks run independently, a month in which both are due simultaneously can compress maintenance scheduling significantly — particularly when a limited IA availability window must be aligned with low aircraft utilization periods.

Aviatize's maintenance control module tracks both the 100-hour inspection and the annual inspection timers independently for every aircraft in the fleet. The annual inspection's calendar-month expiry date (§91.409(a)) and the 100-hour cumulative Hobbs/tach threshold (§91.409(b)) are displayed side by side in the aircraft's maintenance dashboard, with configurable advance warning windows — typically 10 hours before the 100-hour limit and 30 days before the annual expiry — giving the maintenance team enough lead time to schedule the IA without operational disruption. The platform also stores the IA's certificate number, authorization number, and renewal date, generating an alert when the IA's biennial renewal (§65.93) is approaching so the school is not caught with an expired authorization at inspection time.

For Form 337 major repair and alteration tracking, Aviatize's digital data and records module maintains a repository of all Form 337 documents associated with each aircraft, linked to the aircraft's maintenance history. When an aircraft undergoes a major alteration — STC installation, avionics upgrade, structural repair — the associated Form 337 and approval data are uploaded and tagged to the aircraft record, ensuring that the aircraft's complete modification history is available for resale, refinancing, or FSDO review without a manual logbook search.