I was numb with shock when I read that in an NTSB accident report. The pilot jumped to his death from 900 feet agl to escape the flame-engulfed cockpit.
I really had not considered any emergency to seem that bad to the occupants until I visited a friend in the hospital who had survived a cockpit fire three days before. He was badly burned over most of his body and had just woken up from a drug-induced coma to help him get through the painful cleaning process. It was awful.
When I had a chance to look at the wreckage, I couldnt help but notice the blood on the canopy latches, signifying the desperate struggle he must have faced while trying to get out of the burning wreckage. After walking out of the burn unit, I cried. No one should have to go through that pain.
The lessons that went into this article came from several pilots who will continue suffering through the pain of skin grafts for several more years. One friend has undergone over two dozen surgeries and faces many more.
The NTSB record shows 82 general aviation accidents involving smoke in the cockpit from 1997 through 1999. It appears that 20 in-flight fires were so vicious that the aircraft occupants were incapacitated before the aircraft struck the ground.
It is painfully clear in every accident in this sample that seconds count. If you detect smoke in the cockpit, take immediate action and troubleshoot on the way down.
Take care of yourself first, particularly if it means putting on a smoke mask and goggles, or going on oxygen. Take action to extinguish the fire and prepare to land immediately.
As in any in-flight emergency, always remember to fly the airplane first, but be forewarned that it may not be easy. Roughly 40 percent of all fire-related accidents resulted in increased injuries to the aircraft occupants because the pilots were unable to maintain aircraft control.
One friend experienced such searing heat on the engine controls that he suffered severe burns when trying to shut off the fuel and engine. Protective clothing may give you an extra edge – for a limited time – while battling the problem, which is something to think about when choosing your flying wardrobe.
Sometimes, smoke in the cockpit is prompted by an electrical problem and is reduced when the pilot shuts off the power. This allows a few precious minutes of extra time to divert.
On the other hand, all of the engine fires and approximately one third of the electrical fires were accompanied by smoke that grew very thick in a very short time. Seconds literally meant the difference between life and death in some of the accidents.
Nearly nine of out ten pilots in this sample experienced thick smoke bad enough that they elected to perform a forced landing. Of these, nearly three quarters performed an off-field landing due to the urgency of the situation.
The good news is that if you can reach the ground and egress before the flames engulf the structure, your chances of surviving with less than serious injuries are roughly 60 percent. The unfortunate remainder were unable to reach the ground and egress before becoming incapacitated by the flames.
In order to maintain control of the aircraft, you need to be able to see. About 25 percent of the reports indicate the smoke was dense enough that it obstructed the pilots vision of either the aircraft instruments or outside the aircraft.
In non-pressurized aircraft, you may be able to ventilate the cockpit by opening the vents or windows. This is a bit of a judgment call. The breeze may clear out the smoke, but it may also fan the flames, like blowing on the embers of a campfire.
If you are operating a pressurized aircraft, you have a couple options. You can open the outflow valve, which will let more air out of the cabin. The expression raise the cabin will help you remember which direction to twist the cabin altitude knob.
Another option, if the aircraft is so equipped, is to crack open the dump valve. This makes a very loud sound, but it can be effective for clearing smoke. If the dump valve is located away from the flight deck, thats even better because it will take the smoke away from the pilot seat.
A glance around a pilot shop or through an aviation supply catalog reveals various forms of smoke masks and personal breathing equipment. The seal around the neck and shoulders is designed to keep out noxious fumes and the hood is designed for some added insulation from a fire.
The objective of the PBE is mainly to provide cleaner air for breathing while it also provides some extra heat protection to your head. If the fire is burning part of the interior of the aircraft, it is likely creating some very noxious gases, which are debilitating if not lethal.
The evidence suggests that the pilots in about a quarter of the accidents succumbed to the smoke and fumes before they could put the airplane down. Would a smoke hood have bought them enough time to get out? Maybe.
Such a device would need to be immediately accessible in flight because during the chaos of a fire in flight, you will still need to simultaneously fight the fire and begin an emergency descent. But some of the devices are difficult to put on.
The primary rule of using such equipment is to take care of yourself first. Make a dry run several times to find the best location for storing your emergency gear and practice donning the equipment while sitting in those cramped confines.
Prevention Through Maintenance
The vast majority of the accidents could be traced to inadequate maintenance or the pilot not adhering to standard operating procedures.
Oil starvation was the leading cause of engine fires. Sometimes this occurred because the ambient temperatures were too cold and the pilot didnt warm up the engine properly. Sometimes oil caps were left off. Sometimes the oil filter was improperly torqued when it was last installed. Oil, of course, is critical to engine cooling, lubrication and changing the pitch of the propeller.
Problems with the exhaust manifolds were the next most common source of engine fires. Typically the welds on an exhaust manifold would fail, allowing hot gases to spray on nearby components that werent designed to withstand hot temperatures.
Welds are particularly prone to fatigue failures. Welds should be inspected regularly for any signs of cracking and corrosion – two problems that should be immediately addressed.
Turbochargers were the next most common component that caused an engine fire. Turbochargers have a compressor and turbine section. Exhaust gases turn the turbine section, which is connected to the compressor section. The compressor takes incoming fresh air and compresses it to much higher pressure, thus allowing the engine to create more power.
However, heat generated by the spinning turbo and the compression of the intake air means turbochargers are very hot. If the manifold from the compressor section fails, very hot air is exhausted into the engine nacelle and will certainly cause thermal damage.
This problem is particularly dangerous when improper materials are used in heat-sensitive areas – as happened in several in-flight fires. It should go without saying that flammable materials should be kept away from sources of ignition, yet people occasionally route plastic hoses next to turbochargers. Unfortunately, the engine nacelle sometimes is a tightly confined place and it is easy for hydraulic lines to be close to exhaust stacks or electrical lines.
The FAA is very specific about the types of materials that can be installed in an aircraft, and that even includes the type of carpeting. While it may seem like over-regulation, the goal is to ensure that materials meet specified levels of flame and fire resistance.
Its tempting to go out to the local carpet outlet to buy carpet at a fraction of the cost an aircraft interior refurbisher would charge you. Although you technically make the aircraft non-airworthy by installing non-certified carpet, the bigger issue is that the carpet may be prone to burning if exposed to an electrical short.
Despite the regulations, however, the unfortunate fact is that some interior components do comply with the standards of flame resistance but produce lethal gases once they are ignited. By the way, you might want to be careful with what cleaning materials you use on the interior. Improper cleaning can strip away the materials flame-resistant coatings.
Access in Flight
If you are flying most light airplanes, the cargo area is probably accessible for a passenger to turn around and inspect. Larger airplanes have baggage areas in the nose or in engine nacelles that are inaccessible during flight.
Before loading, inspect these areas to make certain there are no loose wires or sources of heat that could lead to a fire, and be certain that the cargo does not contain any hazardous material that might readily ignite. Dont trust passengers to know what is proper for loading into baggage.
A handheld fire extinguisher that is properly secured in place should be carried on the flight deck of every aircraft. Halon 2101 is commonly used in handheld fire extinguisher bottles because it will not cause collateral damage and wont cloud your vision. It will, however, make you nauseous.
To ensure maximum firefighting capability, a handheld fire extinguisher must be charged to its normal pressure. Its prudent to preflight a fire bottle by checking to make certain there is no damage to the handle, that the pin is in place and not bent.
Check the gauge to make certain the nitrogen pre-charge is at a sufficient level. If you have to use a fire extinguisher, think of the acronym PASS. Pull the pin. Aim the fire nozzle. Squeeze the trigger or handle. Sweep the source and base of the fire.
Engine Fire and Smoke
Smoke coming from the engine was the cause of 61 of the 82 smoke in the cockpit general aviation accidents between 1997 and 1999. A relatively high percentage of these – roughly a quarter – ended in fatalities.
My friend felt heat under the instrument panel, but there were no signs of smoke in the cockpit. He considered the possibility that an electrical device was over-heating, so he shut down the electrical system.
A fire had originated in the engine compartment and was streaming underneath the aircraft. It basically cooked the underside of the aircraft.
An engine fire requires immediate action, and will probably necessitate an emergency landing, very likely off-field. Do not delay. Without an engine fire extinguishing system, you really have no way to suppress the fire unless shutting off the fuel selector happens to do the trick.
Each aircraft manual will have the manufacturers recommended procedures for coping with a fire in flight. In general, you should always follow the recommended procedures, unless in your judgment the procedure would make the emergency worse.
The fire/smoke drill in most light airplanes goes something like this: Check for the source of the fire first. If an engine fire is present, switch the fuel selector or the fuel shutoff valve to off. This will stop the flow of fuel to the engine on your side of the firewall, leaving less fuel in the fuel lines going to the engine to burn.
Close the throttle, then move the mixture to idle-cutoff. If your aircraft is equipped with electric fuel boost pumps, turn those off. To prevent further smoke from entering the cockpit, the heater and defroster should be off.
You may need to open the cabin vents to clear the smoke from the cockpit. In case the fire was caused by the exhaust stack developing a leak and allowing hot air to impinge upon electrical wires, turn off the master switch.
Choose a suitable field, crack the door open, and prepare for the emergency landing.
In a twin, you may have the option to continue flying to a suitable airport if you can control the engine fire. The first and foremost rule when handling a fire in a twin is to continue flying the airplane.
While it is important to maintain aircraft control, its also important to shut down the engine as soon as possible. Pilots who have delayed shutting down a burning engine have experienced catastrophic failures of the wing spar. If you are absolutely certain that the emergency actions put out the fire, then you have the option to divert to the nearest suitable airport and landing with an inoperative engine.
The specific procedures for handling electrical smoke are different from an engine fire, though the underlying principles of taking immediate action to protect yourself and maintaining aircraft control still apply.
From 1997 to 1999, 14 general aviation aircraft experienced electrical fire accidents. Now, what the accident records dont tell us is the number of electrical fires that were stopped in the earliest stages of a malfunction and prevented from becoming worse.
The good news is that in 12 of the accidents the pilots detected electrical smoke in its earliest stages and turned off the master switch. They were able to land and egress the aircraft with just minor injuries. Half of the accidents involved smoke thick enough that the pilots performed off-field emergency landings.
Electrical fire produces a bluish smoke that has an acrid smell. The general procedure anytime you detect electrical smoke is to turn off the master switch immediately. Next, turn off the switches to all of the electrically powered devices. Some manuals suggest pulling the circuit breakers at this point. If a circuit breaker is hot, that is probably the offending device. Dont push it back in.
Lets assume you took these steps immediately at the first hint of smoke, and after a couple minutes the smoke doesnt seem to have grown any worse. If the smoke occurred in VMC conditions, stay VFR and head toward the nearest suitable airport (which you should have done at the very first hint of smoke anyway).
If possible, leave your electrical system shut down. If you turn off the source of electrical power at the first wisp of smoke, you may be lucky enough to stop the source of heat (electrical power) before the fire reaches a self-sustaining point. Thats why immediate action is so important.
So what constitutes the nearest suitable airport? For starters, the emphasis should be on nearest. You need to get this aircraft on the ground quickly. Since this is an emergency situation the regulations allow you to take whatever action necessary to resolve the emergency, and this includes intruding into a Class B, C or D airport without a clearance.
A NORDO airplane busting into a busy airport creates confusion for the controllers and other aircraft in the pattern, but thats their problem. Besides, these kinds of airports are more likely to have airport rescue and fire fighting services available, which may be a desirable response when you land. The nearest suitable airport is a judgment call that will depend on your situation.
Smoke while in IMC has frightening potential, but is rare, with only a couple of accidents during the three-year data sample. If you can divert to VMC, do it. If not, youre stuck in one of those difficult situations that leave you with few options.
With everything shut off separately, turn on the master switch and wait a minute to see if the smoke returns. If it does, the short circuit is in your main electrical bus and you are out of luck. Your only bet is to head for the nearest VFR conditions and hope you break out.
If no smoke returns, then consider which electrical component would be most valuable. Given the sage advice of aviate, navigate and communicate, Id rank the importance of components in that manner. Consider turning on a navigational device. If that components circuit breaker is cold, turn on the component and wait to see if smoke reappears. If you can live with just this component to proceed to a safe landing, you might consider leaving everything else off.
Once you restore a navigation instrument, consider which route you should fly if you remain NORDO. Remember the acronym AVE-F. It stands for assigned, vectored, expected, filed. That is the priority of the routes you should fly.
The altitude should be the highest of the MEA, expected and assigned altitudes. (Think MEA for the acronym to remember this.) You might consider turning on a communication radio for a short time, broadcasting an emergency message to ATC, then shutting the radio off. Its a judgment call on your part.
If you cant restore your navigational instruments but can restore your communication radio, controllers can provide vectors to get you to an airport. They might even be able to give you an ASR or PAR approach. An ASR approach is a non-precision approach in which the controller will give you headings to fly and will inform you when to descend to the MDA.
A PAR approach is similar to shooting an ILS, except the controller gives you deviations from the centerline and glideslope. Flying a successful PAR approach is just like flying an ILS, with smooth, small corrections. Some approach control facilities need to maintain their own currency giving ASR and PAR practice approaches, and during quiet portions of the day you might be able to receive a practice ASR approach.
Its a good maneuver to practice and keep in your back pocket, hoping of course that youll never have to use it for real under these circumstances.
Some pilots carry a handheld GPS or communications radio, either of which gives you some real alternatives if you cant energize the ships systems. Some handheld GPS units will fly instrument approaches, and in a true emergency its OK to ignore the stipulation that the approaches are for reference only.
Navigating off a handheld radio is a dicier proposition, and shooting a localizer approach off a handheld nav/comms tiny display is not something anyone will want to do twice. Better in that case to establish communications and get vectors if you can.
After walking out of the burn unit at the trauma center, it struck home as never before that precious seconds count at the first sign of a fire. While there is a certain level of protection designed into the aircraft through the use of fireproof, fire resistant and flame resistant materials, your ability to fight a fire is very limited.
At the first hint of an engine fire, take immediate action. Be spring-loaded to assume the worst if you even think you feel some abnormal heat coming through the fire wall. Dont wait to see if it gets any worse.
Turn toward the nearest airport and immediately start thinking about the procedures for battling an engine fire and getting the aircraft on the ground.
For my friends, its too late. But the one enduring lesson they would pass along: Do not delay one nanosecond.
-by Pat Veillette
Pat Veillette is an aviation safety researcher and training pilot at a major carrier.