Sometimes, I think there are pilots who do not understand the relationship between speed, building time, and money. Especially those with only a bit of flight time in their logs. They need to build time; yet, they fly their cross-country training flights at 75 percent power and proclaim a \u201cneed for speed.\u201d<\/p>\n
The idea that airplanes are supposed\u00a0to go fast is one part of why inexperienced pilots fly too fast. Another part comes from low-time flight instructors who have not figured it out yet themselves. It is not until the low time pilot or new flight instructor goes out, buys an airplane\u2014, and consequently, becomes responsible for the fuel bill, do they realize the importance of proper flight planning and cruise speeds. I was no different\u2014I had to become responsible for the fuel bill to fully understand.<\/p>\n
With just a little math, here is the difference between cruising right and cruising wrong.<\/p>\n
Using basic numbers, a Cessna 172 at 75 percent power consumes 8.4 gallons per hour (gph). If the pilot flies the airplane at 55 percent, consumption drops to 6.2 gph. In context of cost, at $4.95 per gallon, the 8.4 gph amounts to $41.58 and 6.2 gph is $30.69 for a difference of $10.89 per hour.<\/p>\n
Now, for a private owner who flies his or her airplane 250 hours a year, that is a savings of $2723. Another way to look at this is for the same amount of money required to fly at 75 percent, the owner can fly the airplane an additional 89 hours at lower power settings.<\/p>\n
Some pilots will argue the reason for flying is to save time. True, but you don\u2019t have to fly fast all the time. There are times when the clock has to be beat; there are times when you can scoff at the clock and enjoy the ride.<\/p>\n
Here is something else to ponder: how much time do you actually save? For example, consider Al Mooney\u2019s fast little cruiser, the M20J. With a Lycoming O-360 on the front end, 75 percent cruise yields 12.5 gph at 7500 feet at ISA at best power. At the same altitude, 55 percent delivers 9.3 gph. Cruise speeds are 164 @ 75 percent power and 144 @ 55 percent. For a typical 300 nautical mile trip, the flight times are 1+49 and 2+05 respectively, a difference of only 16 minutes.<\/p>\n
The cost in fuel, at an average of $4.95 a gallon, is a difference of $15.84\u2014too high, for saving only 16 minutes of time. Personally, I would leave 16 minutes earlier to save the almost $16 in gas.<\/p>\n
If you take this to a higher level of thinking and apply the savings across the life of the engine at 2000 hours, you would save a total of $31,680. That alone, would pay for the cost of the engine\u2019s overhaul. Now, take it a step further and consider operating a small flight school with seven aircraft. Total savings with the fleet for the life of the engines approaches $225,000. A large flight school or other company operating 100 airplanes could save more than $3 million.<\/p>\n
Pilots I have talked with about this sometimes say, \u201cBut I have to pay by the time, not the fuel.\u201d True enough. However, this is what I refer to as \u201crental car mentality.\u201d (Not my car, I don\u2019t have to take care of it!)\u00a0By using higher power settings, the FBOs and flight schools have to buy more fuel so they are losing the money, right? Actually, they are not; they simply pass the costs down to the renters in the form of higher rental fees. And like most pilots, I object mightily to higher rental fees.<\/p>\n
Think about the benefits of flying a little more slowly, saving gas, and enjoying the ride. On the next post, I will explain the difference between max endurance and max range.<\/p>\n
-30-<\/p>\n
\u00a92011 J. Clark<\/em><\/p>\n Subscribe by email<\/a><\/p>\n Note: please go to<\/em> <\/em>my blog<\/em><\/a> <\/em>to view vids and photos<\/em><\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" Sometimes, I think there are pilots who do not understand the relationship between speed, building time, and money. Especially those with only a bit of flight time in their logs. They need to build time; yet, they fly their cross-country … Continue reading