I would like to suggest a revision to the published form to track Hobbs time rather than Tach time. Most flying clubs use Hobbs time to bill airtime because it is more accurate than Tach time and will always be higher than Tach time. Hobbs time tracks hours starting from the time the engine starts to shutdown. If pilots are using the tach time to estimate fuel usage, then they are not getting the full deduction that they are entitled because that time will vary with RPM settings. My experience is that the tach time is about 80 percent of the Hobbs time. If the aircraft does not have a Hobbs meter pilots are better off using a stopwatch to track the time than using the tach.
PA-28-161 N9396C (KGAI)