Private pilot · ACS PA.II.C
Engine Starting
Engine starting is short, but it's where people on the ramp are most at risk, and where an engine problem first shows up.
Why this one matters
Propeller strikes on the ramp are among the most avoidable and devastating accidents in aviation. A disciplined start (look, call clear, watch the oil pressure, know when to stop) protects people on the ground and the engine itself.
Can’t miss
- •Follow the POH starting checklist for the conditions: normal, cold, hot or flooded starts each have their own procedure.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- •Look around, turn on the beacon, and call "Clear!" loudly before engaging the starter; wait for anyone nearby to move away.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- •Treat every propeller as live: a broken magneto ground wire can let the engine fire if the propeller is moved.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- •Oil pressure must rise to at least the POH minimum within the POH time (commonly about 30 seconds, about 60 in very cold weather); if it doesn't, shut down immediately.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- •Observe the starter's limits: the AFH guide is no more than 30 seconds of continuous cranking, then at least 30 seconds to a minute to cool (many trainer POHs are stricter). If it won't start within the limits, stop and troubleshoot.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- •Position the airplane so the propeller blast won't hit people, other aircraft or hangars, and not over loose gravel.(Private Pilot ACS (FAA-S-ACS-6C), PA.II.C.S1)
- •External power: matching voltage, the POH sequence, and the cable confirmed disconnected and clear before taxi; then verify the alternator is charging.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
What you should know
Starting in different conditions K1 · K2
- Normal start: per the checklist, typically mixture rich, throttle open only the POH amount (often about 1/4 inch), prime as needed, master on, beacon on, "Clear!", brakes set and held, one hand on the throttle ready to retard it, then the starter. Right after it starts, set the POH idle (generally about 800 to 1,000 RPM) so oil pressure can build without wear at high RPM, and check the oil pressure.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- Cold weather: preheat the engine (and oil, as the POH says) at or below the POH temperature, and expect it as temperatures approach and drop below freezing. Use the POH cold-weather priming; thick oil and a weak battery make cranking slow, so respect the starter limits rather than grinding.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations; AC 91-13)
- Hot engine: fuel vaporizes in the lines; the hot-start procedure usually uses little or no prime, because priming a hot engine is what floods it.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- Flooded engine is a different procedure: typically mixture idle cutoff and throttle fully open while cranking, per the POH; as it catches, mixture rich and throttle back.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- External power: confirm the ground power unit's voltage matches the airplane (12 or 28 volts; a mismatch can damage the electrics and avionics), follow the POH battery and master-switch sequence with avionics off as directed, and have the ground crew disconnect it and show you the cable is clear of the propeller before taxi. A GPU start can hide a dead battery or a charging failure: check the ammeter or loadmeter after start.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
Limits and aborting K3 · K4
- Starters overheat: crank for the time limit in the POH, then let it cool before trying again.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- If oil pressure doesn't rise to the POH minimum within the POH time (about 30 seconds in most conditions, about 60 in very cold weather), shut the engine down immediately: serious internal damage is likely.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- Engine fire during start, per the POH: keep cranking with the mixture at idle cutoff and the throttle fully open (fuel pump or selector off as directed) to draw the fire in and starve it. If the engine starts, run it briefly as the POH says, then shut down and inspect. If it doesn't start or the fire continues: stop cranking, mixture cutoff, fuel off, master and magnetos off, get out, use the extinguisher, and don't restart until it's inspected.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- If the starter stays engaged after the engine starts (the warning light or the sound), shut down.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
Propeller safety R1
- Never touch or turn a propeller as if it were safe: a broken P-lead means a magneto can fire the engine with the switch off.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- Look around, beacon on, call "Clear!" and wait. Watch for people approaching once the propeller is turning.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
- Hand-propping is a last resort and never done alone: two properly trained people, both familiar with the airplane and the technique. The person at the propeller directs; the other, familiar with the controls, sits in the airplane holding the brakes (never an unfamiliar person). Chock the main wheels or tie the tail down, use firm ground free of gravel, wet grass, ice or oil, and agree the call-and-response commands beforehand.(Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations)
On the flight
ACS standards
- Position the airplane considering structures, other aircraft, wind, and people and property nearby; complete the checklists.(Private Pilot ACS (FAA-S-ACS-6C), PA.II.C.S1-S2)
What your instructor is watching for
Your instructor watches for a real look around and a loud "Clear!" before every start, the brakes held, an eye on the oil pressure right after the start, and the correct procedure for a cold, hot or flooded engine.
Scenarios
Decide what you would do first, then see the worked answer.
It's 15°F. The airplane has been outside overnight.
How do you approach the start? See the worked answer
Preheat the engine (and the oil, per the POH) before trying to start: at 15°F after a cold soak, that is expected. Then use the POH cold-weather priming and start, expect slow cranking from thick oil and a weak battery, and respect the starter limits rather than grinding.
Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations; AC 91-13
You stop for fuel on a hot day and the engine won't restart after the usual priming.
What's likely, and what do you do? See the worked answer
The usual priming likely flooded a hot engine. Clear it with the POH flooded-start procedure: mixture idle cutoff and throttle fully open while cranking, then mixture rich and throttle back as it catches. Next time, use the hot-start procedure (little or no prime). Respect the starter limits.
Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations
As you prepare to start, someone walks toward the airplane from behind the wing.
What do you do? See the worked answer
Don't start. Wait until they're clear and acknowledge you, then call "Clear!" and look again before engaging the starter.
Airplane Flying Handbook (FAA-H-8083-3C), Ground Operations
Common mistakes
Calling "Clear!" without looking.
People can be near the propeller where you didn't check.
Instead: Look all around, call clear, and wait a moment before starting.
Over-priming a hot engine.
It floods the engine.
Instead: Use the hot-start procedure in the POH.
Ignoring the oil pressure after start.
Running without oil pressure is likely to cause serious internal damage.
Instead: Watch for it to rise within the POH time; shut down immediately if it doesn't.
Now train it
Say it out loud, hear it asked, and take the quick check in this lesson’s practice pack. It tracks your shaky spots.
Got it?
When it feels solid, practice engine starting out loud with our examiner.
Your progress is saved in this browser. Create a free account to keep it on every device, with your shaky spots and mock oral results in one place.
Go to the source (free)
Teaching this? The instructor lesson plan →
Sources
- Airplane Flying Handbook (FAA-H-8083-3C): Ground Operations
- Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C)
- Private Pilot ACS (FAA-S-ACS-6C): Area II
- Your airplane's POH/AFM: normal procedures and checklists
Study aid, not FAA guidance. Regulations change; check the current text at eCFR and the ACS. Checked against current sources 2026-11-12.