Not a dumb question at all. You can use a sand hourglass if you want, just so
long as you use the same method all the time. That is, use hobbs OR tach OR
wris****ch, just be consistent.

No, the regs do not REQUIRE you to use the same method every time, but you'll
play hell explaining your method to the FAA if they come a'snoopin'.

Jim


"O. Sami Saydjari"
shared these priceless pearls of wisdom:

-OK, dumb question. For 100-hour inspections (or 50 hours until oil
-change), is this measured in Hobbs time or Tach time?
-
--Sami
-N2057M, Piper Turbo Arrow III


Jim Weir (A&P/IA, CFI, & other good alphabet soup)
VP Eng RST Pres. Cyberchapter EAA Tech. Counselor
http://www.rst-engr.com