FAR 23.2310 — Seaplane Buoyancy Requirements
FAR 23.2310 sets buoyancy standards for seaplanes and amphibians, requiring 80% excess buoyancy and stability against capsizing if a float or hull floods.
FAR 23.2310 is an airworthiness standard that applies to airplanes designed to operate on water — that means seaplanes and amphibians certified under Part 23. It sets the minimum buoyancy the manufacturer must build into the floats or hull so the airplane stays safely on the surface.
The rule has two parts:
- 80% excess buoyancy: The floats or hull must provide buoyancy that is 80 percent greater than what is needed to support the airplane's maximum weight in fresh water. This margin accounts for rough conditions, weight shifts, and minor leaks.
- Flooding margin: The airplane must have enough reserve so it will stay afloat at rest in calm water without capsizing if a float compartment or hull section experiences a likely flooding event.
Why it matters operationally: as a seaplane pilot, you're trusting that a damaged float won't immediately sink or roll the airplane. This regulation is the design backstop — but you still need to inspect float compartments preflight and pump them out as required.
Five FAA-written-style questions. Instant explanations, every answer cites its source — no account needed.
You are flying VFR in Class E airspace at 8,500 feet MSL during the day. What are your minimum visibility and cloud clearance requirements?