91.237 Aircraft speed

• (a) Except as provided in paragraph (b), a pilot must not operate an aircraft at an indicated speed of more than 250 kts below an altitude of 10 000 feet AMSL when--
  • (1) that aircraft is operated IFR in Class D, E, F, or G airspace; or
  • (2) that aircraft is operated VFR in Class C, D, E, F, or G airspace.
• (b) Paragraph (a) does not apply when--
  • (1) the minimum safe speed of the aircraft prescribed in the flight manual is more than 250 kts and the aircraft is operated at that minimum safe speed; or
  • (2) the aircraft is being operated at an aviation event in accordance with 91.703.