FAR 103.1 — Ultralight Vehicle Applicability

FAR 103.1 sets the rules of the road for ultralight vehicles in the U.S. and, just as importantly, defines what counts as one. If your aircraft fits the definition, Part 103 applies — and you don't need a pilot certificate or aircraft airworthiness certificate to fly it. If it doesn't fit, you're operating under a different part of the FARs entirely.

To qualify as an ultralight vehicle, the aircraft must:

• Be used (or intended) for manned operation by a single occupant
• Be flown for recreation or sport only
• Have no U.S. or foreign airworthiness certificate
• If unpowered, weigh less than 155 pounds
• If powered:
  • Weigh less than 254 pounds empty (excluding floats and emergency safety devices like a ballistic parachute)
  • Have a fuel capacity of 5 U.S. gallons or less
  • Be incapable of more than 55 knots CAS at full power in level flight
  • Have a power-off stall speed of 24 knots CAS or less

Why it matters: exceeding any single limit — even by a pound or a knot — pushes the vehicle out of Part 103 and into the world of certificated aircraft and pilot certificates.