When The Lights Go Out In IFR

Next to an onboard fire, an electrical power failure in the clouds is the biggest challenge a pilot can face.

The situation where a pilot flying in IMC conditions loses all electrical power is as bad as it gets. To avoid getting into that situation in the first place, you should really understand how your airplane’s electrical system works. The electrical system of a single engine airplane is a delicate balancing act with little or no redundancy. On the one hand you have the airplane’s battery…

The battery’s primary job is to supply cranking power to the starter for routine engine starts. But, the battery serves a back-up role as a temporary supply of electric power to radios in an emergency. After the engine starts…

The alternator supplies electric power for radios, lights, de-icing and anti-icing equipment, and other appliances, and to maintain a ‘trickle‘ charge on the battery. The trickle charge keeps the battery fresh and ready for the next start.

Electric system failure can usually be caught early on by a pilot who knows the system and who is watching for problems. In the clouds you should always be watching for problems. You should spend some quality time with your airplane’s POH and your airplane’s A&P technician learning about the specifics of the airplane’s systems, but in general, if the alternator malfunctions or fails you will be left with a battery that is low and dying. If you only first notice the problem by wondering why the radio seems weak and the lights seem dim, it will probably already be too late. The solution: know how to ‘preflight‘ your electrical system, and how to troubleshoot the system while in flight.

If the electrical system in fact dies, and you are in the clouds your survival will depend on just how crafty and cool you become. Lets look at the situation, exactly. Without an electrical system, you cannot use the radio, so you have two-way radio communication failure… and navigation failure. That means you can’t know exactly where you are or where you are going. A hand held GPS would be a great help now, but it also must run off depleting batteries. Without electricity your transponder will not work and therefore ATC can only get a ‘primary‘ target off your airplane. Primary targets on today’s computer radar screens easily get lost, so controllers may lose the ability to ‘follow‘ you. Without electricity your lights — and pitot heat — will not work.

The Good News: The only good thing about this situation is that the engine and magnetic compass will be unaffected; otherwise you are literally flying around lost in the dark.
The Bad News: Of course, the most ominous part of the problem is that without electricity you cannot shoot an instrument approach. You have no safe way to get through the clouds and back on the ground.

The FAA has countless rules, and procedures. There seems to be a regulation for everything down to the smallest detail — but not for electrical failure. There are no rules to guide you if you lose all electricals in IFR conditions — you’re on your own. Anything you might try to save yourself will be an experiment. Each situation would present different challenges requiring a different plan of attack, but here are some suggestions — these are only suggestions and will not work in every case:

  1. Find some VFR. You should never take an airplane into the clouds without first knowing where the nearest VFR conditions are located. I always end my pre-IFR conversation with FSS by asking, ‘by the way, where is the nearest VFR?’ If you lose your electrical system, your best hope is to fly into VFR conditions. Then it becomes a race — what will happen first … a) finding VFR conditions, or b) running out of fuel in the clouds? Of course, as you travel you will not know where you are. You might consider cruising at a VFR altitude (even or odd thousand foot +500), because in the clouds nobody else will be level at those altitudes — but danger will still exist from IFR aircraft climbing or descending through those altitudes.
  2. Fly toward flat terrain. You should have a very good idea of your position before the electrical system failed, so work from your last known position. Hopefully, VFR conditions and flat terrain are in the same direction. But if VFR conditions are beyond your fuel range, at least get away from hills and mountains if possible. The ocean is flat. If it’s an option, you could do a time-speed-distance problem and calculate when you were out over the water. Plus, over the ocean, your absolute altitude and your altimeter reading will be roughly the same number. You could descend all the way to sea level, hoping to break out of the bottom of the clouds before the altimeter reached zero and without hitting a passing ship! If you did pop out under the clouds and above the waves, you could turn back toward shore and land on the beach.
  3. Attempt a landing — don’t wait until the fuel runs out. After you have done all you can to get over flat terrain, it will probably be better to attempt a descent while you still have power. Start a very slow descent — no more than 200 feet per minute. If you pop out very low, find a farmer’s field and call it a day. At night, matters will be much worse. If you make this descent while you still have fuel, you could ‘go-around‘ if you did not see anything flat enough to land on. You could then climb and keep going in hopes of a finding a better spot later. If your descent starts because the fuel is gone, then you have only one chance. Of course, this descent is into an unknown location, so even over flat terrain there could be towers or buildings.

BOTTOM LINE: The consequences of an electrical system failure in the clouds are deadly and should give every pilot ample incentive to do excellent weather planning, and become better acquainted with their airplane systems. If the best you can do is fly out over the ocean, or make a slow descent over what you think might be flat terrain, the situation is dire. If you ever experience a complete electrical failure in IFR and you are able to land on the beach, or make it safely onto a field or highway, you should get out of the airplane and kiss the ground. Then thank whatever ‘higher power‘ you believe in for your miraculous survival.