Regulation Text
§ 1.2 Abbreviations and symbols.
The following abbreviations and symbols are used in the rules of this chapter:
AFM means airplane flight manual.
AGL means above ground level.
ALS means approach light system.
APU means auxiliary power unit.
ASR means airport surveillance radar.
ATC means air traffic control.
ATS means Air Traffic Service.
CAMP means continuous airworthiness maintenance program.
CAS means calibrated airspeed.
CAT II means Category II.
CMP means configuration, maintenance, and procedures.
DH means decision height.
DME means distance measuring equipment compatible with TACAN.
EAS means equivalent airspeed.
EFVS means enhanced flight vision system.
ETOPS means extended operations.
FAA means Federal Aviation Administration.
FFS means full flight simulator.
FM means fan marker.
FSTD means flight simulation training device.
FTD means flight training device.
GS means glide slope.
HIRL means high-intensity runway light system.
IAS means indicated airspeed.
ICAO means International Civil Aviation Organization.
IFR means instrument flight rules.
IFSD means in-flight shutdown.
ILS means instrument landing system.
IM means ILS inner marker.
INT means intersection.
LDA means localizer-type directional aid.
LFR means low-frequency radio range.
LMM means compass locator at middle marker.
LOC means ILS localizer.
LOM means compass locator at outer marker.
MAA means maximum authorized IFR altitude.
MALS means medium intensity approach light system.
MALSR means medium intensity approach light system with runway alignment indicator lights.
MCA means minimum crossing altitude.
MDA means minimum descent altitude.
MEA means minimum en route IFR altitude.
MEL means minimum equipment list.
MM means ILS middle marker.
MOCA means minimum obstruction clearance altitude.
MRA means minimum reception altitude.
MSL means mean sea level.
NM means nautical mile.
NOPAC means North Pacific area of operation.
NOPT means no procedure turn required.
OEI means one engine inoperative.
OM means ILS outer marker.
OPSPECS means operations specifications.
PACOTS means Pacific Organized Track System.
PAR means precision approach radar.
PMA means parts manufacturer approval.
POC means portable oxygen concentrator.
PTRS means Performance Tracking and Reporting System.
RAIL means runway alignment indicator light system.
RBN means radio beacon.
RCLM means runway centerline marking.
RCLS means runway centerline light system.
REIL means runway end identification lights.
RFFS means rescue and firefighting services.
RNAV means area navigation.
RR means low or medium frequency radio range station.
RVR means runway visual range as measured in the touchdown zone area.
SALS means short approach light system.
SATCOM means satellite communications.
SSALS means simplified short approach light system.
SSALSR means simplified short approach light system with runway alignment indicator lights.
TACAN means ultra-high frequency tactical air navigational aid.
TAS means true airspeed.
TCAS means a traffic alert and collision avoidance system.
TDZL means touchdown zone lights.
TSO means technical standard order.
TVOR means very high frequency terminal omnirange station.
VA means design maneuvering speed.
VB means design speed for maximum gust intensity.
VC means design cruising speed.
VD means design diving speed.
VDF/MDF means demonstrated flight diving speed.
VEF means the speed at which the critical engine is assumed to fail during takeoff.
VF means design flap speed.
VFC/MFC means maximum speed for stability characteristics.
VFE means maximum flap extended speed.
VFTO means final takeoff speed.
VH means maximum speed in level flight with maximum continuous power.
VLE means maximum landing gear extended speed.
VLO means maximum landing gear operating speed.
VLOF means lift-off speed.
VMC means minimum control speed with the critical engine inoperative.
VMO/MMO means maximum operating limit speed.
VMU means minimum unstick speed.
VNE means never-exceed speed.
VNO means maximum structural cruising speed.
VR means rotation speed.
VREF means reference landing speed.
VS means the stalling speed or the minimum steady flight speed at which the airplane is controllable.
VS0 means the stalling speed or the minimum steady flight speed in the landing configuration.
VS1 means the stalling speed or the minimum steady flight speed obtained in a specific configuration.
VSR means reference stall speed.
VSRO means reference stall speed in the landing configuration.
VSR1 means reference stall speed in a specific configuration.
VSW means speed at which onset of natural or artificial stall warning occurs.
VTOSS means takeoff safety speed for Category A rotorcraft.
VX means speed for best angle of climb.
VY means speed for best rate of climb.
V1 means the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance.
V2 means takeoff safety speed.
VFR means visual flight rules.
VGSI means visual glide slope indicator.
VHF means very high frequency.
VOR means very high frequency omnirange station.
VORTAC means collocated VOR and TACAN.
Research Notes
§ 1.2 — The FAA's Official Abbreviations List
Section 1.2 is shorter than § 1.1, but length is not a measure of its importance — this is the FAA's official decoder for every abbreviation and symbol used across 14 CFR. When a term such as "MAA" appears in § 91.121 or "ALS" in § 91.175 and the regulation's meaning is unclear, § 1.2 is where the agency defines it. It contains no interpretation and no commentary — only the abbreviation and what it stands for.
There are roughly two flavors of entries worth knowing: the ones pilots use on every flight, and the ones that only surface when working a dispatch, certification, or maintenance question.
The pilot-relevant short list:
| Abbreviation | Stands For |
|---|---|
| AFM | Airplane Flight Manual |
| AGL | Above Ground Level |
| ALS | Approach Light System |
| APU | Auxiliary Power Unit |
| ASR | Airport Surveillance Radar |
| DH | Decision Height |
| MDA | Minimum Descent Altitude |
| MEA | Minimum En Route IFR Altitude |
| MEL | Minimum Equipment List |
| RVR | Runway Visual Range (measured in the touchdown zone area) |
The back-of-the-house entries mostly matter to operators, mechanics, and certification engineers: CAMP (Continuous Airworthiness Maintenance Program), CMP (Configuration, Maintenance, and Procedures), OPSPECS (Operations Specifications), PMA (Parts Manufacturer Approval), TSO (Technical Standard Order), ETOPS (Extended Operations), FFS / FSTD / FTD (the simulator hierarchy), and IFSD (In-Flight Shutdown). These do not need to be memorized — what matters is knowing they live in § 1.2 if a regulation references one.
The honest framing: § 1.2 is a reference, not a study aid, and it is not exhaustive. FAA Order 7110.65 carries the ATC abbreviations. The Pilot/Controller Glossary covers operational shorthand. Individual Advisory Circulars introduce their own. § 1.2 is the 14 CFR list — its boundary is drawn clearly at the regulations themselves.
What an Examiner Asks About § 1.2
Most examiners do not march an applicant through 100-plus abbreviations. They tend to pick one or two that tie back to a procedural reg — because that is where understanding actually shows up. Common questions include:
- "What does AFM stand for, and what's in it?" — Airplane Flight Manual. Ties directly to § 91.9 and § 91.103.
- "What's the difference between an AFM and a POH?" — The AFM is the FAA-approved, aircraft-specific document required to be on board. The POH is the manufacturer's pilot handbook; in many GA airplanes (especially newer Cessnas and Pipers), the POH is the AFM when it carries the FAA-approval pages.
- "What's an ALS, and where does § 91.175 reference it?" — Approach Light System. § 91.175(c)(3)(i) permits descent below DH/MDA when the approach light system is in sight, with the caveat about red terminating bars and red side row bars.
- "What's MAA?" — Maximum Authorized IFR altitude. It appears on enroute charts and ties to airspace and navaid reception.
The examiner is not testing recall but whether the applicant can connect a § 1.2 term to the reg that uses it. The connections matter more than the dictionary.
When an Obscure Abbreviation Matters
This is where § 1.2 earns its keep — when reading a reg, encountering an unfamiliar acronym, and needing to know where to look.
For example, in § 91.213(d) — the inoperative-equipment provision for aircraft without an MEL — "MEL" is referenced repeatedly. A quick check confirms § 1.2 defines MEL as "minimum equipment list." Continuing through the section, a reference to "TSO" equipment also appears, and § 1.2 covers that as well (Technical Standard Order). The regulation makes sense once the vocabulary is decoded.
There is a trap, however. When studying wake turbulence separation behind a "heavy" aircraft, a search of § 1.2 for "heavy" comes up empty — and so do "large," "small," and the other ATC weight categories. The reason is that "heavy" is an ATC term, not a CFR term. It lives in AIM 4-3-2 and the Pilot/Controller Glossary. § 1.2 only covers the abbreviations the FAA uses inside 14 CFR — the regulations themselves.
The lesson: § 1.2 is the decoder for the regs. When a term is not there, walk the hierarchy — AIM, then the Pilot/Controller Glossary, then the relevant Advisory Circular, then the FAR/AIM glossary up front. Knowing where to look beats memorizing what is in any one place.
Angle of Attack is an aviation flight-training brand founded by Chris Palmer, a two-time Master Aviation Educator and Gold Seal CFI. We decode the FARs so pilots understand not just the words, but what they mean in the cockpit.
AOA's Decoded pages are plain-English interpretation for training and reference. They are not legal advice and do not replace the official regulation. Always confirm current requirements against the authoritative source before acting.