Airframe

The airframe is the mechanical structure of an aircraft, excluding the powerplant. It includes the fuselage, wings, empennage (tail assembly), landing gear, and flight control surfaces. The airframe is subject to structural loads during flight and must be maintained within its certified design limits.

Structural Load Limits

Each airframe is certified for specific g-limits (multiples of gravitational acceleration): normal category is +3.8g / −1.52g; utility category is +4.4g / −1.76g; aerobatic category is +6.0g / −3.0g. Exceeding these limits can cause structural damage not always immediately apparent — the aircraft must be inspected before further flight.

Maintenance

Airframe condition is inspected during annual airworthiness inspections. Corrosion, fatigue cracking, and impact damage are the main concerns. Significant airframe repairs must be approved by TC or performed to approved data by a licensed AME.

Related Terms

See also: Aircraft Engine, Empennage, Airworthy.