GUMPS stands for Gas, Undercarriage, Mixture, Props, Switches (or Seatbelts, depending on who taught you). It’s a memorized prelanding flow, not a written checklist, and it exists mainly to keep you from landing a retractable with the gear still up. You run it on downwind, again on final, and again after any go-around. The written before-landing checklist backs it up afterward. That’s the whole thing. The rest of this is what each letter actually means and why the mnemonic is built the way it is.
What each letter means
G — Gas. Fuel selector on the proper tank, or BOTH if your aircraft calls for it. Check your POH; some singles land on a specific tank, others require BOTH for takeoff and landing regardless of fuel state. This is also a good moment to glance at fuel quantity and confirm the pump is on if your checklist calls for it during landing.
U — Undercarriage. Gear down and locked, three green lights, verified visually if your airplane has a mirror or a wing-mounted indicator. This is the letter GUMPS exists for. Everything else in the mnemonic could be handled by a general prelanding scan; the gear check is the one item that needs its own dedicated, repeated, spoken confirmation because getting it wrong is expensive and irreversible by the time you’re on short final.
M — Mixture. Rich, or set as required for field elevation and density altitude. At sea level this is usually full rich. At a high-density-altitude airport it may not be, so this is a POH check, not a reflex.
P — Props. On a constant-speed prop, full forward (high RPM, low pitch) so you have immediate power available for a go-around. This item doesn’t apply to a fixed-pitch prop, which is one reason some flight schools teach a four-letter GUMS for fixed-gear, fixed-pitch trainers and save the P for complex-airplane transition.
S — Switches, or Seatbelts. This is the letter with the most variation. Some instructors use it for fuel pump, landing light, and other switches you want set before landing. Others use it for seatbelts and shoulder harnesses secured. A few add a second S for speed, checking you’re at the right point on the approach. None of these are wrong. Pick whichever your instructor taught you and fly it consistently rather than mixing versions mid-flow.
Why the mnemonic exists: gear-up landings
GUMPS is built around one failure mode. Retractable-gear singles like the Piper Arrow and Beechcraft Bonanza have a well-documented history of gear-up landings, and in the overwhelming majority of cases it isn’t a hydraulic failure or a motor that quit. It’s a pilot who got busy, distracted, or interrupted, and never selected the gear handle down. NTSB and insurance-industry data on this type of accident consistently point to the same root cause: a missed step, not a mechanical one.
A spoken, repeated flow is the countermeasure. Saying “gear down, three green” out loud, at more than one point in the pattern, catches the failure mode that a single silent glance at the panel does not. That’s why both the Bonanza A36 template and the Piper Arrow template repeat the gear item across four checkpoints: before-taxi, run-up, before-landing, and short final. Redundancy on the one item that actually kills people costs a few seconds and is worth every one of them.
When to run it
Three points, minimum, in a normal traffic pattern:
- Downwind, abeam the numbers or wherever your pattern normally calls for the prelanding flow.
- Final, before you commit to the landing.
- After any go-around, before you re-enter the pattern. This one gets skipped more than any other. A go-around resets your workload and your attention, and if the gear got extended for the aborted landing, it’s still down; if it wasn’t, you need it down again before the next approach. Either way, run the full flow again rather than assuming the state from the first attempt still holds. If you’re building out your own procedure for this moment, the go-around decision checklist covers the call itself, not just the mnemonic that follows it.
Some pilots add a fourth pass, abeam the numbers on downwind before turning base, effectively doubling up with the downwind check above. The exact count matters less than the habit: never turn from base to final without having run GUMPS at least once in that circuit, and never land after a go-around without running it again.
GUMPS vs. the written before-landing checklist
This is where pilots sometimes get confused, so it’s worth being precise. GUMPS and your written before-landing checklist are not the same tool doing the same job twice.
GUMPS is a flow. You fly it from memory, hands moving across the panel in a practiced sequence, no paper involved. It’s fast, it happens at the point in the pattern where you’re already task-saturated, and it’s built to catch the one item — gear — that has the highest cost if missed.
The written checklist is what you read afterward, once you’re stabilized, to verify the flow actually got completed correctly. This is the standard do-verify structure I wrote about in flows first, then checklists: you do the work from a practiced flow, then check it against paper. GUMPS is the flow half of that pattern, specifically for the landing phase.
Treat them as backing each other up, not as redundant. If you only fly the mnemonic and never cross-check it against your written checklist, you lose the paper trail that catches the day your memory flow itself breaks down. If you only run the written checklist and skip the spoken flow, you lose the repeated, load-bearing gear check that GUMPS was built to provide. Both, in that order, is the point.
Build it into your own checklist
If you fly a retractable, your before-landing section should already have the gear item called out clearly, and GUMPS is what backs it up in the air. You can see how this looks laid out on paper in the Arrow and Bonanza A36 templates, both built around the same four-checkpoint gear redundancy described above. If you’re starting from scratch, the free checklist builder lets you lay out your own before-landing section with the gear check repeated at the points where your pattern actually needs it, then verify the whole thing against your POH before you fly it.
Common questions
What does GUMPS stand for?
Gas, Undercarriage, Mixture, Props, Switches. Some pilots fly it as Gas-Undercarriage-Mixture-Propeller-Seatbelts, or add a final S for Speed. The letters vary slightly by flight school and aircraft, but Gas, Undercarriage, and Mixture never change, because those are the items that bite.
Do I need to run GUMPS in a fixed-gear airplane?
The U for undercarriage doesn't apply, but Gas and Mixture still do, so plenty of fixed-gear pilots keep a shortened flow. The full five-letter mnemonic earns its keep specifically in retractables, where a skipped gear extension is the failure it exists to prevent.
Is GUMPS a substitute for the written before-landing checklist?
No. GUMPS is a memorized flow you run from habit, hands on the panel, no paper involved. The written checklist is what you read afterward to confirm the flow actually got done. Treat GUMPS as the doing and the checklist as the verifying, not two versions of the same step.
When exactly should I run a GUMPS check?
On downwind, again on final, and immediately after any go-around before you re-enter the pattern. Some pilots add a fourth pass abeam the numbers. The point isn't the exact count, it's never flying a base-to-final turn without having run it at least once in that circuit.