The In-Flight Fire, the Two Emergencies Pilots Confuse for Each Other, and the Checklist That Has to Live in Your Hands Before the Smoke Reaches Your Eyes

In-flight fire is not a single emergency. Engine fire and electrical fire have different causes, different checklists, and different consequences if you mix them up. The NTSB has documented cases where cockpit smoke incapacitated pilots within 90 seconds of onset - not from the fire itself, but from the smoke. The pilots who ran out of time didn’t lack knowledge. They lacked a reflex built before they needed it.

What Causes an Engine Fire in a Piston Single?

Engine fires in piston singles most commonly stem from a cracked or leaking fuel line, a carburetor problem, or an induction system fire from a flooded start that got out of control. You may see flame or black smoke from outside the cowl - on a Cessna 172, a flicker at the left edge of the cowling is a common early indicator. Often, you’ll smell burning avgas before you see anything. The odor is sharp and distinctive.

What’s the Engine Fire Checklist?

Your POH is the authority for your specific airplane, but across most training aircraft the sequence follows a consistent pattern:

1. Mixture - idle cutoff
2. Fuel selector - off
3. Throttle - closed
4. Magnetos - off
5. Master switch - off
6. Cabin heat and air - off

That last step gets rushed past in training and it shouldn’t. In most small aircraft, cabin heat routes through a shroud around the exhaust pipe. If that shroud has developed a crack - common in aging training fleet aircraft - hot exhaust gases or flames can enter the cabin through the heater duct. Leaving cabin heat on during an engine fire opens a direct channel from the combustion event to the cockpit.

After completing the checklist, establish your glide at best glide speed and identify landing options. Not airports - landing options. What is beneath and in front of you that will support an emergency landing right now.

What Do You Do After the Engine Fire Checklist?

You land. An active engine fire is not a situation where you troubleshoot whether it might self-extinguish. It’s not a situation where you navigate back to your departure airport because your car is parked there. You find the best available surface and put the airplane down. Climbing to extend your options burns the clock and potentially the airframe.

How Is Electrical Fire Different from Engine Fire?

Electrical fire announces itself differently. The smell is burning insulation or hot wiring - sharp, acrid, similar to a soldering iron or burning plastic. Nothing like burning avgas. Smoke may appear from behind the instrument panel, from the avionics stack, or from cabin vents. Often the smell comes before any visible smoke.

Common causes include aging or chafed wiring, a charging system problem, an alternator fault, or avionics drawing more current than the bus was designed to handle. In older aircraft, wiring insulation degrades over time, and the inspection cycle doesn’t always catch every failing wire before it becomes an in-flight problem.

What’s the Electrical Fire Checklist?

The instinct when you smell smoke near the panel is to start tracing circuits - pull a breaker, cycle a switch, see if the smell changes. That’s the wrong first move.

1. Avionics master - off
2. Master switch - off

You cut electrical power first. You starve the source. Yes, you just lost most instruments and all radios momentarily. That gets addressed next. The priority in the first seconds is to stop feeding whatever is burning.

If you have an active fire and a fire extinguisher, aim at the base with short bursts. Dry chemical extinguishers are effective but will coat your avionics with residue. Halon or carbon dioxide extinguishers are preferable in the cockpit because they don’t leave destructive residue. Know which type you have before you need it.

Crack the vents or side window immediately. Smoke inhalation, even brief exposure, impairs judgment, reduces visual acuity, and creates confusion. NTSB accident files document pilots making increasingly poor decisions in the minutes following initial smoke exposure - not because they panicked, but because the smoke was doing quiet neurological work in the background.

After the immediate threat is controlled, restore power selectively - one circuit at a time - watching for any sign that smoke returns when you add each circuit back. When you have your radio, declare the emergency.

When Should You Declare a Mayday?

Immediately, once you have communications. Pilots hesitate because they don’t want to overreact, aren’t sure of the severity, or worry about explaining themselves afterward.

The FAA has made the legal position clear: declaring an emergency in good faith carries legal protection. Certificate action cannot be taken against a pilot who declared and turned out to be wrong about the severity. What you lose by hesitating and being right about the severity is everything. What you lose by declaring and being wrong is some paperwork.

The transmission is straightforward:

“Mayday, Mayday, Mayday.” Your callsign. Nature of the emergency. Position and altitude if you have them. Your intentions.

If you’re on frequency with a controller, say it directly to them. If you don’t know your frequency, squawk 7700 and transmit blind on 121.5 MHz until someone answers.

What If You Can’t Tell Which Type of Fire You Have?

You smell something wrong and see haze forming, but you can’t immediately identify the source. Here’s the framework:

• If the smell suggests fuel, or if anything is visually associated with the engine compartment, work the engine fire checklist.
• If the odor resembles burning insulation and the source appears to be the panel or avionics area, work the electrical fire checklist.
• If you have genuine ambiguity, default to the electrical fire checklist first.

The reasoning is conservative: if it’s an electrical fire and you leave the master on, you continue feeding it. If it turns out to be something else and you cut the master, you’ve lost some equipment but haven’t made anything worse.

What Does the ACS Actually Expect on Your Checkride?

The private pilot Airman Certification Standards cover emergency operations, including fire. The examiner isn’t just listening for checklist items recited in correct order - that’s the floor. The ceiling is demonstrating you understand why each step exists, that you have a mental model of what happens after the checklist ends, and that you can make reasonable decisions under simulated pressure.

Students frequently trail off after the last printed checklist item. When the examiner asks “and then what?” there’s a pause. Your preparation has to continue through landing site selection, approach considerations, radio calls, and passenger briefing.

How Do You Brief a Passenger Before Flight?

A thirty-second pre-flight briefing changes what happens in your cabin during an emergency. Cover the seatbelt, cover the door latch, and add one sentence: “If I tell you to brace, I need you to do that immediately without asking questions.”

A passenger who doesn’t know what to expect may reach for the door handle at the wrong moment, grab the yoke, or freeze. A calm, briefed passenger is worth more than almost anything else you can have in the cabin during an emergency.

How Do You Build the Reflex Before You Need It?

The emergencies that go wrong are rarely the ones where the pilot didn’t know the checklist. They’re the ones where the pilot couldn’t access the checklist under stress. Information that lives in your head and a reflex that lives in your hands are different things.

Pull your POH and read both fire procedures - engine and electrical. Close the book and walk through them from memory. If you get stuck, read again. Then locate your fire extinguisher in the airplane you fly and verify you can reach it from the left seat with your seatbelt on.

If you fly with a regular instructor, ask them to run an emergency procedures review that goes beyond checklist recitation - a conversation that ends with “and then what?” until you’ve talked yourself all the way to the ground.

Key Takeaways

• In-flight fire is two emergencies, not one. Engine fire and electrical fire have different checklists and different first steps - confusing them under stress is a documented fatal error pattern.
• After an engine fire checklist, you land. Immediately. Your job is not to troubleshoot or navigate back to your departure airport.
• Electrical fire: cut power first. Avionics master off, then master switch off. Stop feeding the source before anything else.
• Declare Mayday without hesitation. Good-faith emergency declarations carry FAA legal protection. The cost of hesitating when the situation is real is everything.
• When in doubt about fire type, default to the electrical fire checklist. It’s the more conservative first response and prevents you from feeding an active electrical fire.
• Build the reflex now. Read both checklists, memorize them, locate your extinguisher, and verify you can reach it seated and belted.