Major alteration

An alteration not listed in the aircraft, aircraft engine, or propeller specifications—

That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or
That is not done according to accepted practices or cannot be done by elementary operations.

Source: 14 CFR 1.1, General definitions.

Related terms

Glossary last updated 2024-07-25.