The complete breakdown of the ATOMATOFLAMES mnemonic — what each letter means, the exact FAR that backs it up, and how to answer when a DPE asks why your tachometer is on the list.
Governing regulation
FAR 91.205(b)
Type of operation covered
VFR day, powered civil aircraft
Number of items
13 letters, 13 equipment categories
Inop equipment rule
FAR 91.213(d) — placard not enough if on 91.205
Companion mnemonic for night
FLAPS (FAR 91.205(c))
What ATOMATOFLAMES actually stands for
ATOMATOFLAMES is the mnemonic pilots use to remember the minimum equipment required for VFR day flight under FAR 91.205(b). It's the first thing a designated pilot examiner (DPE) will probe during the equipment portion of an oral exam, and it shows up on every private and commercial checkride.
Here is each letter, what it stands for, and the exact regulatory language behind it:
Letter
Equipment
Notes
A
Airspeed indicator
Required on every powered civil aircraft
T
Tachometer
One for each engine
O
Oil pressure gauge
For each engine using a pressure system
M
Manifold pressure gauge
For each altitude engine (turbocharged/supercharged)
A
Altimeter
Pressure-sensing
T
Temperature gauge
For each liquid-cooled engine
O
Oil temperature gauge
For each air-cooled engine
F
Fuel gauge
One indicating quantity in each tank
L
Landing gear position indicator
Only if the aircraft has retractable gear
A
Anti-collision light system
Required for small aircraft certificated after March 11, 1996
Plus shoulder harnesses on aircraft manufactured after July 18, 1978
That's the whole list. Memorize it, but more importantly, understand it — examiners almost never ask you to recite it. They ask you to apply it to a specific airplane on a specific day.
Frequently Asked Questions
Q1What does ATOMATOFLAMES stand for?
ATOMATOFLAMES is the mnemonic for VFR day required equipment under FAR 91.205(b): Airspeed indicator, Tachometer for each engine, Oil pressure gauge, Manifold pressure gauge for each altitude engine, Altimeter, Temperature gauge for each liquid-cooled engine, Oil temperature gauge for each air-cooled engine, Fuel gauge for each tank, Landing gear position indicator (if retractable), Anti-collision lights (post-1996 aircraft), Magnetic direction indicator, ELT, and Safety belts. Memorize the list, but understand each item — examiners test application, not recitation.
Q2Is ATOMATOFLAMES in the FARs?
The mnemonic itself is not. The underlying list is codified in FAR 91.205(b), which specifies the powered civil aircraft instruments and equipment required for VFR day flight. ATOMATOFLAMES is just a study aid pilots and CFIs invented to remember the regulation. On a checkride you should be able to cite FAR 91.205(b) directly, and ideally walk the examiner through the regulation rather than rely on the mnemonic alone.
Q3What is the difference between ATOMATOFLAMES and FLAPS?
Adaptive questions surface your weak areas. Examiner Reed runs full ACS-coverage oral exams. Mock checkrides predict your DPE pass rate.
5 questions/day • No credit card
Why this mnemonic exists
FAR 91.205 is the regulation that tells you what instruments and equipment must be installed and operative for the type of operation you're conducting. Subsection (b) covers VFR day. Subsections (c), (d), and (e) layer on additional requirements for VFR night, IFR, and high-altitude flight respectively — that's where the FLAPS and GRABCARD/GOOSEACAT mnemonics come in.
You are the pilot in command. FAR 91.7 makes you responsible for determining the aircraft is in condition for safe flight, and FAR 91.213 governs what you do when something on this list is broken. ATOMATOFLAMES is just a memory hook — the real skill is reading the regulation and the airplane's equipment list and reaching a defensible go/no-go decision.
Walking through each letter in detail
A — Airspeed indicator
One ASI, calibrated and operative. If the pitot tube is bent, blocked, or the static port is taped over, this item is inoperative.
T — Tachometer for each engine
A twin needs two. On a glass-panel single, the engine RPM display on the PFD/MFD satisfies this requirement so long as it's functioning per the AFM.
O — Oil pressure gauge
Required for each engine that uses a pressurized oil system, which is essentially every certified piston engine you'll fly.
M — Manifold pressure gauge for each altitude engine
This one trips students up. "Altitude engine" is defined in FAR 1.1 as a reciprocating engine with rated takeoff power producible from sea level to an established higher altitude — meaning turbocharged or supercharged. A normally aspirated 172 does not require a manifold pressure gauge under 91.205. A turbo Bonanza does.
A — Altimeter
A pressure altimeter. Doesn't have to be encoding for VFR day (encoding is required for Mode C airspace under FAR 91.215, a separate rule).
T — Temperature gauge for each liquid-cooled engine
Almost no general aviation piston aircraft are liquid-cooled, so this is usually moot — but it matters in Rotax-powered LSAs and a handful of legacy types.
O — Oil temperature gauge for each air-cooled engine
The one that almost always applies. Lycomings and Continentals are air-cooled, so they need an oil temp gauge.
F — Fuel gauge indicating quantity in each tank
Each tank gets a gauge. The gauge only has to be accurate when reading empty per certification standards (14 CFR 23.1337) — it doesn't excuse a stuck or wildly inaccurate gauge from being placarded inoperative.
L — Landing gear position indicator
Only if the aircraft has retractable gear. Fixed-gear airplanes skip this letter.
A — Anti-collision lights
Required for small civil airplanes certificated after March 11, 1996. Older aircraft are not required to have them by 91.205, but if installed they must work for VFR night flight under FAR 91.205(c). On modern trainers it's a strobe + beacon system.
M — Magnetic direction indicator
The wet compass. It must be installed, swung, and have a current compass correction card.
E — ELT
An ELT meeting FAR 91.207. Battery within service life, registered with NOAA, and the 12-month inspection current.
S — Safety belts
A seat belt for each occupant over age 2. Shoulder harnesses are required at each front seat on small civil airplanes manufactured after July 18, 1978 (FAR 91.205(b)(13)).
What to do when something on the list is inoperative
This is where ATOMATOFLAMES becomes a checkride centerpiece. The DPE points at a placarded fuel gauge and asks: "Can we go?"
The answer flows from FAR 91.213(d), the inoperative equipment provisions for aircraft without an MEL. The decision tree:
Is the inop item part of the VFR day type certification (Kinds of Operations Equipment List in the POH)?
Is it required by FAR 91.205 for the type of operation you're conducting?
Is it required by an Airworthiness Directive?
Is it required by any other rule (e.g., 91.207 ELT, 91.215 transponder)?
If the answer to all four is no, then under 91.213(d) you may:
Remove the inoperative item or deactivate and placard it "INOPERATIVE,"
Have a pilot or mechanic (as appropriate) make the airworthiness determination, and
Fly.
If the answer to any of the four is yes, the airplane is unairworthy for that flight until the item is repaired or addressed via a Special Flight Permit (FAR 21.197).
A fuel gauge is on 91.205. A placard alone does not make the aircraft legal. Ask any examiner — this is the trap question.
Aircraft with an approved MEL
If your aircraft operates under an approved Minimum Equipment List, FAR 91.213(a) governs and the MEL becomes the controlling document. Most piston trainers don't have one; most turbine and Part 135 aircraft do.
Common DPE questions involving ATOMATOFLAMES
"Walk me through 91.205 for VFR day."
"The landing light is burned out. Can we fly today?" (Trick — landing light isn't on 91.205(b); check 91.205(c) for night and check the KOEL.)
"The oil temp gauge is sluggish on runup. What's your call?"
"Why is a manifold pressure gauge on the list when our 172 doesn't have one?"
"Show me where shoulder harnesses are required and tell me why our 1975 Cherokee doesn't have them at the back."
"One fuel gauge is stuck on full. Walk me through 91.213(d)."
If you can answer those six questions cold, you'll handle anything a DPE throws at the equipment block.
ATOMATOFLAMES vs. the other equipment mnemonics
Mnemonic
Regulation
Purpose
ATOMATOFLAMES
FAR 91.205(b)
VFR day required equipment
FLAPS
FAR 91.205(c)
Adds to VFR night (Fuses, Landing light if for hire, Anti-collision, Position lights, Source of electrical power)
GRABCARD or GOOSEACAT
FAR 91.205(d)
IFR equipment
GOOSE A CAT
FAR 91.205(d)/(e)
IFR + above FL240 (DME)
Think of it as a stack: VFR night flight requires ATOMATOFLAMES plus FLAPS. IFR requires all of the above plus GRABCARD. The list grows; it never shrinks.
How GroundScholar helps with this
Memorizing ATOMATOFLAMES takes ten minutes. Defending it under DPE pressure takes reps. GroundScholar's oral exam simulator runs you through equipment-list scenarios with a different inoperative item every time — placarded fuel gauges, dead landing lights, sluggish DG, expired ELT batteries — and forces you to walk through 91.205 and 91.213 out loud, the way a checkride actually works.
Every FAR cite the AI examiner uses is verified against the live regulation, so when it tells you 91.213(d) has four conditions, you can click through and read them. The adaptive drilling notices when you're shaky on a specific letter (manifold pressure trips most students) and serves you more of those scenarios until they're automatic.
Read your airplane's POH section 2 (Limitations) and find the Kinds of Operations Equipment List (KOEL).
Read FAR 91.213 and write the four-step inop decision tree on a notecard.
Drill ATOMATOFLAMES until you can recite it in eight seconds.
Drill scenarios, not letters. "Mag compass card missing — go or no-go?" beats "What does the second M stand for?" every time.
The DPE is testing your judgment, not your spelling.
Ready to drill this until it's automatic?
GroundScholar's mock checkride will ask you about ATOMATOFLAMES the way your examiner will — with a busted gauge in your face and a takeoff clearance pending. Get the reps before the real thing.
ATOMATOFLAMES covers FAR 91.205(b) — VFR day. FLAPS covers the additional items in FAR 91.205(c) needed for VFR night: Fuses (spare set or three of each kind), Landing light (if operated for hire), Anti-collision lights, Position lights, and Source of electrical power. For VFR night you need every ATOMATOFLAMES item plus every FLAPS item. The lists are cumulative, not alternative.
Q4If a fuel gauge is inoperative, can I still fly VFR day?
Generally no — not without action. A fuel quantity indicator for each tank is required by FAR 91.205(b)(9), so a stuck or broken gauge makes the aircraft unairworthy until it's repaired. FAR 91.213(d) only lets you placard and defer items that are not required by 91.205, an AD, the type certificate, or another rule. A fuel gauge fails the 91.205 test, so placarding alone is not enough. You'd need a Special Flight Permit under FAR 21.197 to ferry it for repair.
Q5Why is a manifold pressure gauge on the ATOMATOFLAMES list?
Because FAR 91.205(b)(4) requires a manifold pressure gauge for each altitude engine. An altitude engine, defined in FAR 1.1, is a reciprocating engine with rated takeoff power producible up to an established higher altitude — meaning turbocharged or supercharged engines. A normally aspirated Cessna 172 has no altitude engine, so the M doesn't apply to it. A turbocharged Bonanza or Mooney does, and the gauge must be installed and operative.
Q6Are shoulder harnesses required by ATOMATOFLAMES?
Yes, on most modern trainers. FAR 91.205(b)(13) requires an approved shoulder harness or restraint system for each front seat on small civil airplanes manufactured after July 18, 1978, and at each forward-facing seat on aircraft manufactured after December 12, 1986. The seat-belt requirement is separate and applies to every occupant. Older aircraft are grandfathered but if shoulder harnesses are installed by STC or original equipment, they must work.
Q7Does ATOMATOFLAMES apply to glass-cockpit aircraft?
Yes. FAR 91.205 doesn't care whether your airspeed indicator is a steam gauge or a pixel on a PFD — it just has to be installed and operative. On a G1000 or similar system, multiple ATOMATOFLAMES items are displayed by the same screen, so a PFD failure can render several required items inoperative at once. The Kinds of Operations Equipment List in the POH will tell you which AHRS/ADC/display failures ground the aircraft for VFR day.
Q8How do I handle inoperative equipment that is on the ATOMATOFLAMES list?
If your aircraft has no MEL, follow FAR 91.213(d). Required items under FAR 91.205 cannot simply be placarded and deferred — the aircraft is unairworthy until repaired or until you obtain a Special Flight Permit under FAR 21.197. If your aircraft has an approved MEL (rare for piston trainers, common in turbine and Part 135), the MEL controls and may allow specific deferrals with conditions and time limits. Always document the determination in the maintenance records before flight.
ATOMATOFLAMES Checklist: VFR Day Equipment | GroundScholar