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Tach, hobbs, maint
Posted: Sat Sep 03, 2022 11:42 am
by bvolcko
Please advise. What are the significant differences between these timers?
My current flight log viewer shows Hobbs:0063.12 Tach:0040.35 Maint:067.25
Re: Tach, hobbs, maint
Posted: Sun Sep 04, 2022 5:44 pm
by Bill Hertzel
The HOBBS timer is the actual Engine running time. It emulates an Electric HOBBS Clock.
Set the HOBBS Minimum RPM to half your idle speed to time whenever the engine is running.
The TACH Timer Speed varies in Proportion to the Engine RPM.
It emulates Old-School Tachometer timers that displayed Total engine revolutions in terms of hours.
You need to set up the 100% point in Menu > System Setup > Engine Monitoring > RPM1 > HOBBS Tach 100% Rpm.
If you set it to 5000 rpm, at 2500 rpm the clock runs at half speed. At 2000 rpm it runs at 40% speed. at 5500 rpm it runs at 110% speed.
You are essentially saying that 5000 revolutions equal One minute, or 300,000 Rev equals One Hour.
The maintenance timer could be used to record the time since the last overhaul.
The Inspection timer could be used to record the time since the last 100 hr inspection.
All these timers are Set/Reset in Menu > System Setup > Time/Date/Hobbs >