Interesting, though, that while the 91.205 of the regs require a tachometer, it doesn't define whether a tachometer is supposed to show anything more than RPM, such as whether it is also supposed to show total revolutions to date.denverpilot said:If they fly an aircraft with a mandatory AD for inspections at certain hours, for one...
And of course no requirement (that I can see) of anything like a Hobbs meter - at least in section 91. Not sure if any of the aircraft related sections have more to say.