Featuring Bob Nardiello
view Bob's bio

 Press play to listen to this tip

Bob Martens:

I know starting a cold airplane remains a mystery to many pilots. Can you cover the best sequence of events to follow for a cold start?

Bob Nardiello:

Well first, let me give a couple of ground rules that I use. Below 20 Fahrenheit, many airplanes are next to impossible to start -- many of them are. Some will start below that temperature. The problem you run in to is, it's very abusive on the airplane's systems. It's abusive on the starter and abusive on the battery to try to start it when it is very, very cold.

The second issue is a very low battery will lend itself to an engine fire situation. And how this happens is if the engine isn't turning over fast enough, you may get a backfire. And remember, you are going to be using a good deal of prime to start the engine when it's cold, and that backfire might cause your intake duct to ignite. And if the battery is very low, you won't be able to pull that flame back into the engine. So it's dangerous to try a start in very cold temperatures, particularly with a marginal battery. As I said earlier, the battery condition is one thing you want to monitor in the winter. You need a good battery.

If it's below 20, monitor your airplane if it is being preheated with a kerosene heater, because you don't want the line people to melt your cowling. Many cowlings have fiberglass parts. If the blast of hot air is not really directed in the engine, but instead, on the cowling, it may damage the airplane. But this works really well in heating the engine and giving you the opportunity for a good start.

Bob Martens:

Is it necessary to preheat again after a stopover?

Bob Nardiello:

Well, it depends. First off, you need to know at your stopover, what the facilities are, if you were to need a preheat. You don't want to stop randomly at an airport, find out you can't get the airplane started because it's too cold, because you went to lunch and didn't come back for 2½ hours. You need to know what the facilities are. But a rule of thumb that I use, I'll just give this to you for what it's worth because it's worked for me.

Temperatures less than 20 degrees: I don't let the airplane sit for more than an hour, and it's pretty much a guaranteed start. Temperatures between 20 and 30 degrees: no more than two hours. Between 30 and 40: 4 hours. And that's always worked for me. So you go beyond that -- if it's 10 degrees, and you leave it out there for two hours, you may have a real problem starting it. And you may need a preheat to get it done, or a warm hangar to get it to start. So use those as a guideline, at least that's what I use.

If you have the need to stay at your location for more than an hour, and it's less than 20 degrees, you may want to schedule a restart. Get out there, restart it, bring the oil temperature back up. It may take you 15 or 20 minutes. Shut it down again and then you're good for another hour.