Plane & Pilot
Friday, July 1, 2005

Saving Money On Fuel

With the price of avgas at record highs, here are some thoughts on getting the most out of your budget

I was told when I bought my first single-engine airplane back in the last century that I could estimate my total hourly operating cost by multiplying fuel expense by three. In those days, I flew a Globe Swift that burned six gallons an hour. Fuel was only about 70 cents per gallon as I remember, so I figured my fuel cost at $4.20 per hour and total cost to operate the Swift at a whopping $13 per hour, an intimidating number in those days." />

Okay, so you’ve decided to fly leaner. The only question remaining is how? On some older airplanes, there may be little choice, as the only leaning device may be the human ear. We were all taught the basic rule of leaning: pull back on the red knob until the engine begins to run rough, then push it back in just enough until the engine runs smooth again.

Fortunately, most modern aircraft use at least a single-probe EGT, and some manufacturers are installing full engine analyzers that sample EGT and CHT from each cylinder, along with cool-down rate, oil temperature and a variety of other parameters. JPI, Electronics International, Alcor, Insight and several other companies offer engine analyzers that allow you to monitor the performance of each cylinder. With any of these installed and reading properly, you can lean to the first cylinder to peak with confidence to maximize power and minimize fuel burn.

The final method of reducing fuel cost is to fly for the shortest possible time, and that may not always be over the shortest distance. The proliferation of GPS has made great circle direct routes more popular, and you obviously can’t fly less than the great circle distance between departure and destination.

Direct routes may be harder to come by when conditions are IFR, however. ATC hasn’t yet fully embraced GPS-direct routes that may cut across a number of established airways, but most of the time in most of the U.S., you should be able to fly direct.

You may be able to reduce your time en route, especially on longer trips, by following pressure patterns. You’ll often need to ad-lib on headings in an attempt to stay with the prevailing winds, so again, this technique may not work in IFR conditions, but you may find that chasing the wind can lead to shorter flights, if over a slightly longer distance.

I once knew a ferry pilot who had his own way of saving fuel. In those days, we most often flew on fixed-price contracts to our international destinations. In other words, whatever was left of the original contract fee at the end of the trip was our profit. When crossing the Atlantic in a twin, Jerry would burn down a predetermined amount of fuel, then shut down an engine, feather the prop and continue the flight on one mill. He’d lose speed, but his mileage would actually increase. When we arrived in Ireland, Jerry was always the last one to land, but he usually managed to make the Atlantic crossing on $100 or $200 less fuel than the rest of us. That’s not a recommended procedure.

Oh yeah, Jerry is flying for a major airline now, driving 757s and 767s. If you’re ever riding in back of an airline jet during a hold for weather and hear the captain announce, “Ladies and gentlemen, we’ll be holding for another hour, so I’ve taken the liberty of shutting down the right engine to save fuel,” don’t be surprised if the captain’s name is Jerry.


Add Comment