Long distance flying using lean of peak fuel operations

Alaskan pilots are accustomed to flying long distances between airfields and hence, they are well prepared to offer a few tips about proper fuel management. Thus, a recent post on the Alaskan Dispatch’s Bush Pilot blog is well worth reading as Alaskan pilot and Charles Lindbergh enthusiast Bill Compton, who regularly makes 2,000 nautical mile flights to and from Alaska in his single engine Beechcraft Bonanza V-35TC aircraft, talked about his “lean of peak” fuel operation method.

As Bill explained to the author of the post, lean of peak refers to:

…leaning an aircraft engine to 30 degrees or more on the lean side of peak exhaust gas temperature. 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.

Using this method, Bill has been able to fly his specially equipped Beechcraft Bonanza V-35TC from Alaska to Hawaii, Australia and Europe numerous times.

Specifically, the Bush Pilot blog explained that by:

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.

It was then noted that most pilots operate their engines 25-75 degrees rich of peak EGT and hence, they are not operating rich enough. In fact, the difference between where pilots should be rich of peak and where they could be lean of peak can be as much as three or four gallons per hour with a six cylinder engine.

Even if you do not fly the same distances that Bill does, his fuel saving advice is well worth noting. Moreover, the Bush Pilot blog noted that Bill is happy to share his advice and even provided his contact details where he can be reached.