We're in the process of adding a customers SR22 to our 135 certificate for IFR use. FSDO is requiring that we track & perform engine maintenance & inspections based on the aircraft hobbs meter that runs when either alternator is operating rather than the 'flight hobbs' which tracks the FAR 1 definition of time in service.

Continental doesn't have an opinion other than it's up to the airframe manufacturer to determine how to calculate time, Cirrus states that MX is based on the flight hobbs, I pointed out that if we were dealing with a G36 then the only hour meter in the aircraft is weight on wheels ie FAR1.

Anyone here operating SE IFR and dealt with this issue before?

Steve....

My shop maintains a fleet of 135 SR22's. They are all on the 400hr phase program and use the "flight" Hobbs to track total time and time between inspections.

Steve,

Good luck. I found it impossible to get a single engine airplane on IFR cert. Could not prove that backup alternator could run necessary equipment, even though you could just go up in the air and see it could run the equipment. No help from FSDO.

Only had a tach in my bird.

In this case then electrical requirements were easy to satisfy, the aircraft is a 2017 G6 with dual alternators, one is 100 amps, the other 70 amps. There's even a supplement included in the POH titled 'Part 135 Electrical Load Shedding Procedure'.

Someone on the COPA forums made me aware of the FAA's new Regulatory Consistency Communication Board (RCCB) - https://www.faa.gov/regulations_policie ... ions/rccb/ , looks like this may be the appropriate avenue to resolve the issue.

Steve,

Thank you for info. Glad Cirrus had the forethought to include the documentation.

Perfect airplane for 135.