Hobbs issue

[3Dreaming]

Are you reading Hobbs time or Tach time. You're better off with Hobbs. Tach time can vary from 15%-18% depending on engine rpm and some older style tachs registered time with just the electrical on. Al Hobbs and Tachs should have an oil pressure switch installed. You usually can reset the proper time on either if needed.

My plane only has a hobbs. Next time my mechanic woeks on it I'm going to see if we can verify how it's actually connected. Flew yesterday and it seems to be working OK. I'll keep an eye on it.

You do know since your airplane is experimental you could check to see how it is wired. If it was a SLSA after you get your sport pilot certificate you could still trace the wire circuit.

[FastEddieB]

Don't all POH's have at least a simplified wiring diagram?

[drseti]

It's usually in the maintenance manual, Eddie.

[FastEddieB]

I think I nearly always find them in POH's. I thought that was SOP.

From my POH:



The next page has the legend. The Hobbs is 22, activated indirectly via an oil pressure switch.

Kinda thing I think an owner should have access to, without needing an AMM.

edited to add: the CT CTLS POH has a similar diagram. Are there any that don't?

[3Dreaming]

His airplane is experimental, so who knows haw it was wired, and if there is a diagram

[FastEddieB]

His airplane is experimental, so who knows haw it was wired, and if there is a diagram

I did not see that in his original post nor in his profile.

What kind of plane are we discussing?

[drseti]

the CT CTLS POH has a similar diagram. Are there any that don't?

Believe it or not, the Evektor SportStar Max AOI doesn't have one. Instead, it says this:

7.13.2 Electrical system scheme
See Aircraft Maintenance and Inspection Procedures - Supplements.

Then later, in Section 8.1, it says:

The manufacturer delivers along with aircraft SportStar MAX the
“Aircraft Operating Instructions (AOI)“ and the “Aircraft Maintenance and Inspection Procedures (AMIP)”.

[FastEddieB]

Believe it or not, the Evektor SportStar Max AOI doesn't have one.

Interesting.

Hasty assumption on my part!

[drseti]

Hasty assumption on my part!

No, logical assumption on your part. Grievous omission on the manufacturer's part.

[3Dreaming]

His airplane is experimental, so who knows haw it was wired, and if there is a diagram

I did not see that in his original post nor in his profile.

What kind of plane are we discussing?

It is in his first post in the "Buying Your Own Airplane for Flight Training " thread.

I read almost every post in every thread, and I have a good memory.

[FastEddieB]

It is in his first post in the "Buying Your Own Airplane for Flight Training " thread.

Found it - Zenith CH601.

Question: Did the builder provide a schematic?

[rcpilot]

It is in his first post in the "Buying Your Own Airplane for Flight Training " thread.

Found it - Zenith CH601.

Question: Did the builder provide a schematic?

I'll have to check the documentation that I have. I'm also going to have the mechanic have a look when I get my next oil change. On the last 2 flights looks like the hobbs is working so it's still a mystery as to what the avionics guys did to make it run ahead.

[azsportpilot]

back in my ultralight days we had a club member with a Buccaneer 2 w/ 582

he would routinely forget to turn off his master switch and the Hobbs would continue to run, adding 8-10 hours before the battery completely died........... must have been wired up improperly

he reached TBO in just one summer, LOL