The Federal Aviation Administration has accepted four ASTM International integration standards as an approved means of compliance for MOSAIC light-sport aircraft certification, giving manufacturers the detailed compliance framework they need to begin certifying new aircraft under the agency’s Part 22 airworthiness rules. The decision removes one of the last remaining obstacles in the certification pathway created by the Modernization of Special Airworthiness Certification (MOSAIC) rule.
Until the FAA’s acceptance of the ASTM standards, manufacturers faced a structural gap: the new regulations existed but the specific compliance tools required to certify aircraft under them did not. The four standards, developed by ASTM International‘s F37 committee, cover airplanes, gliders, powered-lift aircraft and gyroplanes. Each integration standard is built around a package of more detailed requirements addressing aircraft structures, flight characteristics, landing gear, engines, propellers, fuel and electrical systems, installed equipment and occupant protection. The packages also cover production testing, quality assurance, maintenance programmes and continued operational safety.
MOSAIC light-sport aircraft certification: what the standards cover
The FAA accepted only the specific versions of the standards listed in its notice. Any future ASTM revisions will require separate FAA acceptance before manufacturers can use them as an approved means of compliance. The agency also noted it has not yet accepted an integration standard for light-sport helicopters; ASTM’s F37 committee continues to develop that standard. Additionally, the FAA accepted ASTM F3840-26 only for powered-lift aircraft, even though that standard includes provisions for multicopters. A standard that would allow manufacturers to classify aircraft in the four covered categories as having simplified flight controls has also not been accepted.
Some aircraft will need to satisfy additional standards depending on intended operations, including night flight, instrument operations, water operations or certain aerial-work missions.
The new standards apply to light-sport category aircraft certificated on or after 24 July 2026 and to eligible experimental light-sport kits whose manufacturers sign compliance statements after that date. Previously accepted standards continue to govern repairs and alterations to aircraft certificated under the old light-sport system, and will also apply to certain kit-built aircraft supported by compliance statements signed before the 24 July date.
Scope of MOSAIC and the route to an airworthiness certificate
The FAA finalised the MOSAIC rule in July 2025. The Experimental Aircraft Association has described Phase One of MOSAIC, which took effect on 22 October 2025, as the most significant transformation to general aviation in more than two decades. Changes affecting sport pilots and light-sport repairmen also took effect in October 2025.
MOSAIC replaces several rigid limits from the original light-sport rules with performance-based requirements. The rule opens the category to aircraft with as many as four seats and permits designs with retractable landing gear, constant-speed propellers and a wider range of propulsion systems. The FAA also removed the 1,320-pound maximum takeoff weight for landplanes; aircraft must instead meet limits based largely on stall speed, maximum level-flight speed and other performance characteristics. The change gives manufacturers room to develop aircraft with greater payload, range and utility than was possible under the original framework.
The FAA’s acceptance of the ASTM standards does not constitute approval of any individual aircraft. Each manufacturer must still design and test its aircraft, follow the applicable standards, maintain a production-quality system and submit a statement of compliance before the FAA will issue an airworthiness certificate. The agency is equally clear that the change does not automatically increase the approved weight or operating limits of aircraft already in service. Existing aircraft continue to operate under the certification basis and limitations that manufacturers used when they were produced.
Part 22 airworthiness rules took effect on 16 July; the 24 July 2026 date marks when the new certification standards begin to govern the issuance of light-sport category airworthiness certificates, making that date the operational starting gun for manufacturers ready to bring MOSAIC-compliant designs to market.
