Class A is the high-altitude airspace where jets cruise. Over the 48 contiguous states it starts at 18,000 feet MSL and runs up to and including FL600. Every flight inside it is flown under instrument flight rules on an ATC clearance (14 CFR 71.33 and 91.135). Student pilots rarely fly there, but you'll be tested on it, and if you're aiming for the airlines, it's where you'll spend your career.
Where Class A Starts And Ends
In the continental United States, Class A runs from 18,000 feet MSL up to and including flight level 600 (about 60,000 feet). You won't see it drawn on a sectional chart, because it covers the whole country above 18,000 feet. See all airspace classes explained.
The legal boundaries are in 14 CFR 71.33. Paragraph (a) covers the 48 contiguous states and the water within 12 nautical miles of their coasts. Paragraph (b) covers Alaska, except the Alaska Peninsula west of 160° W and airspace less than 1,500 feet above the surface. Paragraph (c) adds offshore areas listed in FAA Order JO 7400.11. Hawaii is not named.
AIM 3-2-2 is blunt: "Class A airspace is not specifically charted." There is no line to look for.
| Item | Requirement | Source |
|---|---|---|
| Floor | 18,000 feet MSL | 14 CFR 71.33 |
| Ceiling | Up to and including FL600 | 14 CFR 71.33 |
| Where | 48 contiguous states, Alaska with exclusions, water within 12 NM of the coast, listed offshore areas | 14 CFR 71.33(a)–(c) |
| Flight Rules | IFR only, on an ATC clearance received before entry | 14 CFR 91.135(a) |
| Pilot | Instrument rating, or an airline transport pilot certificate | 14 CFR 61.3(e) |
| Radio | Two-way, on the frequency ATC assigns | 14 CFR 91.135(b) |
| Transponder | Mode C (altitude reporting) | 14 CFR 91.215(b)(1) |
| ADS-B Out | 1090 MHz extended squitter only | 14 CFR 91.225(a) |
| VFR Weather Minimums | Not applicable | 14 CFR 91.155(a) |
| Altimeter Setting | 29.92 inches of mercury | 14 CFR 91.121(a)(2) |
| On Charts | Not specifically charted | AIM 3-2-2 |
Sources: 14 CFR on eCFR (current to 8 October 2026) and AIM 3-2-2 on faa.gov, both checked 13 October 2026.
The Rules For Class A
- IFR only: Every flight needs an IFR clearance. VFR flight isn't allowed.
- Instrument rating: The pilot must be instrument rated.
- Equipment: A two-way radio on the ATC frequency, a Mode C transponder and ADS-B Out.
These rules are in 14 CFR 91.135 and 91.225.
Section 91.135 is short and strict. The clearance has to be in hand before you enter, not requested at 17,900 feet, and you stay in two-way contact with ATC throughout. A deviation needs a written request to the ATC facility at least 4 days ahead, under 91.135(d). The exception is a failed transponder, where ATC can approve continued flight to the destination or a repair shop straight away.
The rating requirement is in Part 61. Under 61.3(e), a pilot in command under IFR needs an instrument rating, or an airline transport pilot certificate. A private pilot without one cannot file into Class A, however capable the airplane.
ADS-B is where owners get caught. Below 18,000 feet the FAA accepts either a 1090 MHz extended-squitter unit or a 978 MHz UAT. In Class A, 91.225(a) accepts only the 1090 MHz equipment. A UAT box satisfies the rule inside the LAX Class B and does not satisfy it at FL190.
Flight Levels And 29.92
Below 18,000 feet, pilots set their altimeter to the local pressure from the nearest station. At 18,000 feet everyone switches to the standard setting of 29.92 inches. From there, altitudes are called flight levels. FL350 means 35,000 feet on a standard altimeter. Because everyone uses the same setting, airplanes stay safely apart even as local pressure changes along the route.
The rule is 91.121: below 18,000 feet, the reported setting of a station within 100 nautical miles of your route; at or above, 29.92. When local pressure is low, an altimeter on 29.92 reads higher than the airplane really is, so 91.121(b) raises the lowest usable flight level:
| Current Altimeter Setting | Lowest Usable Flight Level |
|---|---|
| 29.92 or higher | FL180 |
| 29.91 to 29.42 | FL185 |
| 29.41 to 28.92 | FL190 |
| 28.91 to 28.42 | FL195 |
| 28.41 to 27.92 | FL200 |
| 27.91 to 27.42 | FL205 |
| 27.41 to 26.92 | FL210 |
Oxygen And RVSM Up High
Class A begins above the altitudes where the oxygen rules start. Under 91.211(a), the required flight crew must use supplemental oxygen for any part of a flight longer than 30 minutes between 12,500 and 14,000 feet MSL, and for the whole time above 14,000 feet. Above 15,000 feet every occupant must be provided with oxygen. An unpressurized airplane at FL180 is past all three lines.
Between FL290 and FL410 inclusive, controllers separate aircraft by 1,000 feet. That band is RVSM airspace, and under 91.180 and Part 91, Appendix G, the operator and the airplane need authorization to use it.
Which Of Our Airplanes Can Reach Class A
The Cessna 162, Piper Warrior and Diamond DA20 we train in are built for the pattern at Van Nuys and the practice area over Simi Valley. The airplane in our fleet that can reach Class A is N422SN, our Cirrus SR22 Turbo: 310 hp, turbocharged, with a ceiling of FL250.
Above 18,000 feet it needs everything on this page: an instrument-rated pilot, an IFR clearance, 1090 MHz ADS-B Out and oxygen under 91.211. Flying it at all takes a high-performance endorsement under 61.31(f), since the engine is over 200 horsepower; ours costs $1,799. Details of the airplane are on N422SN, our Cirrus SR22 Turbo.
Want to feel the climb first? A 60-minute discovery flight for $229 puts you at the controls over Los Angeles, a long way below Class A. If you are planning a route to the airlines, book a free consultation and we will lay out the ratings, the hours and the cost in order.
How Pilots Get To Class A
The path runs through the instrument rating. At You Fly LA, students start with a private pilot certificate at Van Nuys, then add an instrument rating, using our full-motion simulator for part of the training. The airline pilot program continues through commercial and instructor ratings to the hours airlines require.
First comes the private pilot license, from $10,400 for our Standard package. The instrument rating then needs 40 hours of actual or simulated instrument time, 15 with an instrument instructor, plus 50 hours of cross-country time as pilot in command (61.65(d)). Our instrument package is $11,700: 20 hours in the airplane, 20 in the simulator, 40 of dual and 10 of ground. Under 61.65(i), up to 20 hours in an FAA-approved advanced aviation training device count, and our Redbird MCX is one.
From Van Nuys you climb through the layers below first: our Class D, the Los Angeles Class B above it and Burbank's Class C next door. The Los Angeles airspace guide covers them, and Class B airspace, using LAX as the example explains the one above Van Nuys.
Frequently Asked Questions
Can You Fly VFR In Class A Airspace?
No. Every flight in Class A is under instrument flight rules with an ATC clearance. The VFR weather table in 14 CFR 91.155 lists Class A as not applicable.
Is Class A The Same Everywhere In The US?
In the 48 contiguous states and most of Alaska, yes. It also covers airspace over the waters within 12 nautical miles of the coast. Hawaii is not named in 14 CFR 71.33, and in Alaska the airspace less than 1,500 feet above the surface is excluded.
Can A Small Airplane Fly In Class A?
Yes, if it's equipped and the pilot is instrument rated and on an IFR clearance. Most training airplanes can't climb that high. Our turbocharged Cirrus SR22, N422SN, can: its ceiling is FL250.
Is There A Speed Limit In Class A?
Not the familiar one. 14 CFR 91.117(a) limits aircraft to 250 knots indicated below 10,000 feet MSL, and Class A starts at 18,000 feet.
Do I Need Oxygen In Class A?
In an unpressurized airplane, yes: 14 CFR 91.211 requires the crew to use oxygen above 14,000 feet MSL. In a pressurized airplane above FL250, every occupant needs at least a 10-minute supply in case the cabin loses pressure.
Which ADS-B Out Does Class A Require?
A 1090 MHz extended-squitter unit under 14 CFR 91.225(a), a requirement in force since 1 January 2020. A 978 MHz UAT is accepted only below 18,000 feet MSL.
Can A Student Pilot Fly In Class A?
Not as pilot in command. 14 CFR 61.3(e) requires an instrument rating, or an airline transport pilot certificate, to act as pilot in command under IFR, and a student pilot holds neither.
Book A Discovery Flight, A Lesson Or A Consultation
Every pilot who cruises at FL350 started with one hour at low altitude. Yours can start at Van Nuys with a 60-minute discovery flight for $229, or a two-hour beginner flying lesson for $349 if you want more time at the controls. To talk through the private, instrument and airline steps first, book a free consultation, or call or text (818) 330-1318. We fly seven days a week from Van Nuys Airport.
