Aircraft speed limits14 CFR 91.117 Aircraft speed
Below 10,000 feet MSL the limit is 250 knots indicated airspeed. The limit drops to 200 knots indicated at or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D area, and beneath a Class B area or in a VFR corridor through one.
By the ATIS Alerts team · Updated October 15, 2026 · Regulation text current as of October 14, 2026. A study aid based on the official regulation text, not legal advice or an FAA interpretation.
At a glance
- Below 10,000 feet MSL: no more than 250 knots (288 m.p.h.) indicated airspeed, unless otherwise authorized by the Administrator (a).
- At or below 2,500 feet above the surface within 4 nautical miles of the primary airport of a Class C or Class D area: no more than 200 knots (230 mph.) indicated, unless otherwise authorized or required by ATC (b).
- Paragraph (b) does not apply inside a Class B area; those operations follow the 250-knot limit in (a).
- In the airspace underlying a Class B area designated for an airport, or in a VFR corridor through one: no more than 200 knots (230 mph) indicated (c).
- If the minimum safe airspeed for an operation is higher than these limits, the aircraft may be flown at that minimum speed (d).
In plain English
Section 91.117 sets speed limits in the busy airspace near the ground. Every limit is an indicated airspeed. The broadest is paragraph (a): below 10,000 feet MSL, no aircraft may fly faster than 250 knots indicated unless the Administrator has authorized it.
Paragraph (b) adds a tighter limit around Class C and Class D airports. At or below 2,500 feet above the surface and within 4 nautical miles of the primary airport, the limit is 200 knots indicated, unless ATC authorizes or requires something else. The paragraph says it does not apply to operations inside a Class B area, which follow the 250-knot rule in (a) instead.
Paragraph (c) protects the airspace under and through Class B. Beneath a Class B area designated for an airport, and in a VFR corridor through one, the limit is 200 knots indicated. Unlike (a) and (b), this paragraph has no "unless otherwise authorized" wording.
Paragraph (d) is the safety valve. If an aircraft's minimum safe airspeed for a particular operation is higher than the limit, it may be flown at that minimum speed.
Common mistakes
- Treating the limits as true airspeed or groundspeed. Every limit in this section is indicated airspeed.
- Mixing up the reference points. The 10,000-foot line in (a) is MSL, while the 2,500-foot line in (b) is measured above the surface.
- Applying the 200-knot Class C and D limit inside Class B. Paragraph (b) does not apply within a Class B area, but (c) sets 200 knots beneath Class B and in VFR corridors through it.
The official text
14 CFR 91.117 as published on the eCFR, current as of October 14, 2026.
(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.
Test yourself
Practice questions from our free FAA written test prep that cite 14 CFR 91.117.
Commercial Pilot
Unless otherwise authorized, the maximum indicated airspeed below 10,000 feet MSL is:
- A. 250 knots.
- B. 200 knots.
- C. 288 knots.
- D. 230 knots.
Show answer
A. 250 knots. 250 knots below 10,000 MSL, 200 knots at or below 2,500 AGL within 4 NM of the primary airport of Class C or D airspace, and 200 knots beneath the lateral limits of Class B or in a VFR corridor through it.
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Questions pilots ask
What is the speed limit below 10,000 feet?
250 knots (288 m.p.h.) indicated airspeed below 10,000 feet MSL, unless otherwise authorized by the Administrator (91.117(a)). Lower limits apply near Class C and Class D airports, beneath Class B airspace and in VFR corridors through it (91.117(b) and (c)).
What is the speed limit in Class D airspace?
At or below 2,500 feet above the surface within 4 nautical miles of the primary airport, 200 knots (230 mph.) indicated, unless ATC authorizes or requires otherwise (91.117(b)). Elsewhere below 10,000 feet MSL the 250-knot limit applies (91.117(a)).
How fast can I fly under Class B airspace?
No more than 200 knots (230 mph) indicated in the airspace underlying a Class B area designated for an airport, or in a VFR corridor through it (91.117(c)).