Airline Pilot Forums

Quick question:

I know an aircraft's speed is limited to 250 KIAS below 10,000 MSL. Is there a speed restriction 10,000 and above? I've been told it was the speed of sound, but I can't find any regulation that says that.

Thanks for the help :)

Quick question:

I know an aircraft's speed is limited to 250 KIAS below 10,000 MSL. Is there a speed restriction 10,000 and above? I've been told it was the speed of sound, but I can't find any regulation that says that.

Thanks for the help :)

The limit is less than Mach 1.0 at or above 10,000. It's in FAR 91. The reason is to avoid sonic booms.

This regulation may have to change if sonic boom-less technology is developed. Several organizations are working on this.

The limit is less than Mach 1.0 at or above 10,000. It's in FAR 91. The reason is to avoid sonic booms.

This regulation may have to change if sonic boom-less technology is developed. Several organizations are working on this.

rickair,
I would like to know where specifically in part 91 this is located. I like to think that I am very familiar with the FAR/AIM due to the fact that I study it constantly, but that is another story. The only regulation I can think of that would be a catch-all is 91.13, also know as carelees or reckless operation. 91.117 relates to aircraft speed restrictions, you can refer to it below. Thanks.

§ 91.117 Aircraft speed.

(a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots (288 m.p.h.).

(b) Unless otherwise authorized or required by ATC, no person may operate an aircraft at or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D airspace area at an indicated airspeed of more than 200 knots (230 mph.). This paragraph (b) does not apply to any operations within a Class B airspace area. Such operations shall comply with paragraph (a) of this section.

(c) No person may operate an aircraft in the airspace underlying a Class B airspace area designated for an airport or in a VFR corridor designated through such a Class B airspace area, at an indicated airspeed of more than 200 knots (230 mph).

(d) If the minimum safe airspeed for any particular operation is greater than the maximum speed prescribed in this section, the aircraft may be operated at that minimum speed.

[Doc. No. 18334, 54 FR 34292, Aug. 18, 1989, as amended by Amdt. 91–219, 55 FR 34708, Aug. 24, 1990; Amdt. 91–227, 56 FR 65657, Dec. 17, 1991; Amdt. 91–233, 58 FR 43554, Aug. 17, 1993]

§ 91.817 Civil aircraft sonic boom.
(a) No person may operate a civil aircraft in the United States at a true flight Mach number greater than 1 except in compliance with conditions and limitations in an authorization to exceed Mach 1 issued to the operator under appendix B of this part.

(b) In addition, no person may operate a civil aircraft for which the maximum operating limit speed MM0 exceeds a Mach number of 1, to or from an airport in the United States, unless—

(1) Information available to the flight crew includes flight limitations that ensure that flights entering or leaving the United States will not cause a sonic boom to reach the surface within the United States; and

(2) The operator complies with the flight limitations prescribed in paragraph (b)(1) of this section or complies with conditions and limitations in an authorization to exceed Mach 1 issued under appendix B of this part.

This should cover your question.

Yeah, I found it this morning when I was reading. Thanks. Main difference between the two regulations being the 250 rule is IAS and the Mach 1 rule is TAS.

Yeah, what he said.