Inspired by the movie depicting Charles Lindbergh's 1927 solo crossing of the Atlantic Ocean, a local pilot has perfected his long distance flying using a method called "Lean of Peak."
"I became fascinated with long distance flight as a young man after seeing the movie 'The Spirit of St. Louis,'" said William "Bill" Compton.
Getting the most distance from his fuel is necessary for Bill Compton, as he regularly makes flights over 2,000 nautical miles to and from Alaska in his single engine aircraft.
"If done properly, lean of peak helps stretch the range of your flight," said Compton.
Compton shared his knowledge of LOP operations with the Anchorage Experimental Aircraft Association's Chapter 42 membership at an Oct. 26 meeting at the Alaska Aviation Museum.
"Lean of peak operation refers to leaning an aircraft engine to 30 degrees or more on the lean side of peak exhaust gas temperature." Compton explained. This protects the engine with lower cylinder head temperatures and lower combustion pressures. Another benefit is less fuel flow for the same power, increasing range."
Compton has flown his specially equipped Beechcraft Bonanza V-35TC from Alaska to Hawaii and Europe numerous times. His Bonanza has modifications to be flown strictly by hand from the left hand seat. Why? In 2002 Compton lost the use of his legs in a motorcycle accident on the Glenn Highway.
"I have flown to Hawaii eight times and one of those was from Australia," Compton said.
Today, after making 16 and 17-hour flights over water using the lean of peak operations, he says a reliable engine is very important.
Use of the LOP by Compton is a result of engine leaning technique and research by George Braly.
Braly, an inventor with the General Aviation Modification, Inc., is considered an expert in Lean of Peak (LOP) aircraft engine operations. Braly proved to Compton's satisfaction that it works better than rich of peak operations.
"Lean of peak offers better engine life, lower cylinder head temperatures, lower fuel flows, more range and a cleaner engine," said Compton.
Using LOP technique has resulted in prolonged cylinder life, compared to frequent premature replacement of cylinders which occurred previously with traditional rich of peak operation.
"Before I started using lean of peak with my engine we had to pull a cylinder every year," Compton added.
After making long distance flights and researching long range operations in his Bonanza, Compton attended a lecture during the Experimental Aircraft Association's 1995 Air Venture Fly-In held yearly in Oshkosh, Wisc.
"I was so impressed after hearing George Braly's lecture that I started doing my own research and reading," said Compton. "I later attended one of his Advanced Pilot Workshops over a weekend and that triggered research on my engine's performance at altitude."
Using a detailed analysis of his engine, a turbocharged TSIO520, Compton was able to gauge his exhaust gas temperatures (EGT), cylinder head temperatures and fuel flow to determine exactly how his engine was performing.
By charting the EGTs of each cylinder during fuel leaning at altitude he was able to determine the perfect fuel flow per injector for each cylinder. He then ordered specific injectors from GAMI, changed them, and came up with the perfect balance of fuel for the leaning process.
According to Compton, most pilots operating their engines 25-75 degrees rich of peak EGT are not operating rich enough. The difference between where they should be rich of peak and where they could be lean of peak can be three or four gallons per hour with a six cylinder engine.
Compton freely gives his high altitude long distance advice to other pilots.
"I checked out some of his techniques and have used many of them on my flights to and from Alaska," said Bob Edison, a well-known pilot who ferries aircraft. "They really do work when you pay attention to your engine's performance."
For more information about LOP, Bill Compton can be reached at wccompton(at)aol.com.
Rob Stapleton can be reached at robstapleton(at)alaska.net.