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MOSAIC Rule: What It Means for Light‑Sport Aircraft
Van’s Aircraft CTO Rian Johnson explains the FAA’s MOSAIC rule and what it will mean for pilots and homebuilders.
In a video release, Van’s Aircraft CTO Rian Johnson outlined the FAA’s MOSAIC rule (Modernization of Special Airworthiness Certification) announced at EAA AirVenture Oshkosh 2025. The MOSAIC rule expands Sport Pilot privileges and redefines Light‑Sport Aircraft (LSA), opening new pathways for both pilots and small manufacturers.
Johnson, who also chairs ASTM International’s F37 Committee, detailed how ASTM F37 — the committee that writes consensus standards for light aircraft — is updating design, performance and safety guidelines to align with the rule. He emphasized clearer compliance routes for builders and OEMs, and broader opportunities for student and recreational pilots under the updated LSA framework.
MOSAIC rule: key changes to expect
The MOSAIC rule brings regulatory shifts rather than technological breakthroughs: it adjusts certification paths, revises category limits for certain aircraft, and relies on ASTM consensus standards for compliance. That means manufacturers can follow accepted industry standards instead of bespoke FAA approvals for many LSA features.
- Expanded Sport Pilot privileges that make more aircraft flyable under Sport Pilot rules.
- New ASTM F37 standards covering design, performance and safety for Light‑Sport Aircraft.
- Manufacturer compliance pathways that reduce certification complexity under the MOSAIC rule.
- Potential for more factory-built and kit-built LSA options as ASTM standards evolve.
Johnson framed these changes as a significant regulatory shift for U.S. general aviation: the MOSAIC rule pairs federal policy with industry-led standards, so builders and pilots alike will need to track ASTM F37 publications and manufacturer guidance as models and rules are updated. For anyone building, buying, or training in LSA-category aircraft, now is the time to review how your aircraft or training program will be affected.
