Part 91General Operating and Flight Rules

14 CFR 91.215 — ATC Transponder and Altitude Reporting Equipment and Use

Transponder with Mode C required in Class A, B, and C airspace, above Class B and C, and above 10,000 MSL (with exceptions).

Regulation Text

All airspace: Each person operating an aircraft in controlled airspace must operate with the applicable equipment: in Class A, B, and C airspace; in all airspace above the ceiling or lateral boundaries of Class B or C airspace up to 10,000 feet MSL; in all airspace at and above 10,000 feet MSL (except below 2,500 feet AGL); within 30 miles of certain primary airports in Class B airspace (the Mode C veil).

Note: This is an excerpt. Refer to the full regulation in eCFR for the complete text.

Plain-English Explanation

A transponder with Mode C (altitude reporting) is required in: Class A, B, and C airspace; within 30 nm of Class B primary airports (the Mode C veil); above the ceiling of Class B or C airspace up to 10,000 MSL; and at or above 10,000 feet MSL (except when below 2,500 AGL). You can fly in Class D, E, or G below 10,000 MSL without a transponder in most cases. If your transponder fails, you can request an ATC deviation to fly without it.

Tested On These Exams

Share this with a fellow pilot

Related Regulations

Pass your FAA exam in 30 days

Pilot Exam Crash Course

This regulation will be on your exam. Get 1,000+ practice questions with instant explanations. 94% of students pass on their first attempt.

$149$7.49/mo50% OFF
Start Free Trial

3 days FREE, then $7.49/mo. Cancel anytime. 2,200+ questions.

Or subscribe for full access

All Exams, All Regulations — $7.49/mo

1,000+ questions covering all FARs. Cancel after you pass.

Cancel anytime. No commitment.

More Part 91 Regulations