After cost of aircraft acquisition, your single largest operating expense is aviation fuel. For the twelve month period ending March 31, 2015 our fuel cost was $81.61 per hobbs hour to operate a Cirrus Perspective™ SR22TN-G3 Tornado Alley Turbo.
We budgeted $4.80 per gallon with an average fuel flow of 17.0 gallons per hour, which was an estimate for fuel flow inclusive of taxi, climb, cruise and decent ($4.8 per gallon x 17.0 gph = $81.60).
During this twelve month period, gas prices fluctuated a good bit, but our budgeted rate was within a nickel of the actual hourly cost. We were helped by falling prices for 100 LL aviation fuel, which dropped below $5.00 per gallon.
Fuel Operating Cost Cirrus SR22 Aircraft
For a shared ownership, with members flying about 220 hours per year the aviation fuel cost will be about $18,000 per year.
The Cirrus SR22TN Tornado Alley Turbo has a Continental TCM IO-550-N engine with 310hp of performance matched with a Hartzell 3-blade lightweight composite prop, which enhances an ultra-smooth ride. The engine is equipped with the Cirrus SMART Turbo GAMIjector® System with custom tuned fuel injectors that are designed to be operated Lean of Peak (LOP).
We agreed to run the engine LOP in economy cruise at about ~75% power, 2500 RPM, 29.6 Manifold Pressure (MAP), with fuel flow about ~15.8 gallons per hour. This power setting delivers about 180 knots at higher single digit altitudes and up to 194 knots in mid-flight levels around 17,000 feet.
Operating the engine at a higher LOP power rating (i.e. 17.5 gph @ 80% power) or even greater fuel flow will have significant fuel and maintenance cost ramifications. For example, a member running the engine two (2) gallons more per hour (80% power) could cost the co-ownership $1,000 more in fuel expense per year.
How the engine is operated is a decision members need to agree on. From an accounting perspective, fuel is a direct variable expense. The cost increases proportionally with the number of hours flown, and you’ll want to match that cost with the appropriate member usage.
It’s okay to adjust your billable fuel rate during the year to match-up with actual operating cost. That’s what we did. It’s a best practice and members should expect billable fuel rate adjustments in an aircraft shared ownership.
Our flights were a combination of short local trips and long cross-country flights. Your operating cost experience may vary.
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