Frugal flying may be some sort of oxymoron, but there are a number of things pilots can do to minimize expenses.
The first and foremost is to maintain your engine and keep it on spec. A fouled spark plug or retarded mag timing can increase your fuel consumption significantly.
Second is speed. I know we fly to get someplace faster, but the laws of physics state that the amount of power to move a plane through the air increases with the square of speed. This means that, within the normal operational envelope of your aircraft, the faster you go the more fuel you use. If you throttle back from, say, 75% power to 65%, you will only lose a few mph but will increase your mpg significantly. On a long cross country, that could have a significant effect on your flight time, but on short hops or $100 hamburger trips you will not even notice the difference.
The other part of the power requirement equation is the drag coefficient for your aircraft: the smoother your plane, the less power needed to move it through the air. This means that things like wheel pants and proper alignment of doors and other parts will help reduce your fuel consumption. There are also some speed mods that will reduce the drag which, in turn, will reduce your fuel burn at a given speed.
The third point is weight. Many of us carry a lot of extra stuff and gadgets in our planes. Added pounds increase engine load, especially on takeoff and climbout. Clean out your airplane, go on a diet and carry thinner passengers. It all helps.
Fourth is leaning the fuel mixture. The main need for full rich is on takeoff and climb-out. At almost all other times you should be leaning your mixture. I know a lot of pilots who lean during taxiing. It saves fuel and can help keep spark plugs clean.
If you are flying a turbo-charged aircraft or radial, you will need to be more careful. Maximum cylinder temperatures occur at stoichiometric, and if you operate there for very long, especially in a turbo-charged engine, you will burn a piston or valve. Multipoint CHT or EGT gauges will help ensure that you are not running in the danger zone. There are some injection systems that allow you to operate on the lean side of peak. These work well if you have the instrumentation necessary to ensure against overheating any one cylinder.
Fifth point is warm-up. Once you start your engine, it is not necessary to sit and idle it until the oil temperature is in the green zone. I recommend that, after start-up, you do your normal checks like oil pressure, charging system, etc., and then start your taxi. (This assumes the engine was properly pre-heated on cold days). The main reason to warm up an engine before takeoff is that aluminum pistons have a higher coefficient of thermal expansion than steel cylinders. If an engine is started and goes to full power immediately, the piston can have excess clearance and not enough oil to prevent metal to metal contact in the cylinder wall. As the load is the same whether you are sitting still or taxiing, I recommend taxiing out to the end of the runway. Your oil temperature should be off the peg when you do your runup.
The sixth and final point is oil. Many people try to save money by stretching their oil changes and flying less often. Those practices may offer short-term savings, but will cost a lot more in the long run. Aircraft that are flown every week or so last a lot longer than hangar queens that sit for months at a time and then are flown only a short distance. It is very critical that an aircraft be flown regularly, and long enough to get the oil temperature up, to evaporate all of the moisture in the oil. In addition, the only way to get rid of the by-products of combustion that end up in your crankcase is to change the oil at least every four months. The less you fly, the more important that becomes.
Sometimes you need to spend money to save money. Sounds like the government, doesn’t it?
Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985. You can contact him at Visser@GeneralAviationNews.com.