Seminole Hobbs dilema

LaBeef

New Member
So I was flying with my instructor yesterday in a Piper Seminole. Once we got back, I went through the shut down checklist and shut off everything including the Battery switch, I looked at the hobbs and it was ####.1, as I get ready to write down the times it suddenly goes to ####.2 ... Now I don't know if I should talk to the Chief CFI and tell them to adjust the total since a .1 with your CFI in the plane comes out to $33 (a weeks worth of lunch).. My instructor wasn't in the plane, (he was tying down the plane) so he didn't see it happen, but when I told him about it he came over and we could hear I guess the Hobbs still going, then it stopped. I don't know if it takes a while to shut down completely but I don't think I should be charged for that .1 since all switches were off.
Any advice?
 
It is my understanding that they are all electrically powered.
If you didn't have any power on in the airplane, you must have seen it wrong in my opinion.

From what I have heard they can run off of the battery switch being on, oil pressure, alternator operating, airspeed sensor or squat type switch on the gear.

As far as i know, if there wasn't any juice flowing, nothing was ticking.
 
Think of it this way..if it just clicked over in a matter of seconds as you mentioned that you flew for probably 5 minutes and 57 seconds of that time. Although sad you did technically fly those 6 minutes.

Aviation is obsurdly expensive and as soon as I stopped nickel and dimeing it, it became alot easier to swallow. Think of the good times such as how many times you flew for 5 minutes and 59 seconds of the hobbs and you managed to turn off the master an instant before it clicked over.

But to be a storm cloud on my own parade think of the next guy who gets in the airplane, turns on the master and is charged 33 bucks for 1 second.
 
In the Seminole the Hobbs runs off oil pressure. According to my instructor, he has shut the plane off and had it click over after as well. It's pretty rare but it happens.
 
It all evens out in the long run - you still end up paying for exactly what you put into your log book.
 
I had something similar happen in an arrow. I started it up and my instructor goes to put his headset on and it breaks ( plastic + -20 OAT= bad for plastic)so we shut down. I sat in the plane for a couple minutes with everything off and the Hobbs clicked over.2. Luckily I didnt have to pay for it because they later found a problem with the meter.
 
In the Seminole the Hobbs runs off oil pressure. According to my instructor, he has shut the plane off and had it click over after as well. It's pretty rare but it happens.


I didn't know if that was normal but I guess it is so I'll just let it go...

I had something similar happen in an arrow. I started it up and my instructor goes to put his headset on and it breaks ( plastic + -20 OAT= bad for plastic)so we shut down. I sat in the plane for a couple minutes with everything off and the Hobbs clicked over.2. Luckily I didnt have to pay for it because they later found a problem with the meter.

How'd they find out there was a problem with it?

thanks for your responses everyone
 
Oh nothing pisses me off more than this. :banghead:

When its some old beater Cessna and you can hear (and watch) the Hobbs flying around as you are cranking it several times trying to get it started.

Or when you glance at it rolling into the ramp, than again as you are leaving the plane and it has jumped the tenth. :banghead:

Every plane that I have flown it has been run off of the oil pressure.
 
Bummer on the hobbs rolling over. I'd definitely say it runs off oil pressure. I would bring the problem to the GM of the company or the chief CFI and ask that you not be charged for the discrepancy. With our flight school this same thing happens from time to time.

Or....you could just pay for the discrepancy and happily log the extra .1 in your logbook. ;)
 
Now if that happens as often as a lot of you are saying it does, something I have never noticed. Then it has to happen all the time even after many have already written down the hobbs time and walked back into the fbo. Why not just write down the time you saw when u turned the plane off and call it a day?

Also, you arent allowed to log time that clicks over after the plane is stopped anyway, forget about logging time after the plane is off. So that is just wasted money.

And running off oil pressure is just dumb. Every hobbs I've ever seen has been either running with the master, squat switch, or wind driven.
 
Every Seminole I have ever been in (42 of them according to logshare) the in/out Hobbs runs off the battery master. Granted every seminole I have been in is owned by ATP, but they DO NOT run off oil pressure. I sit in the right seat, watch the student turn on the master, and the little hour glass starts clicking. Also, student forgets to turn off the master....time is ticking.
 
Both Seminoles I've flown use the oil pressure from the right engine to actuate the Hobbs. You can imagine which one got shut down most often in training. ;)

LaBeef, if it were me I would get the school to at least note what you experienced. It's not unheard of for the switch to stick. If it fails completely in the near future, you could make a case for a refund. If the switch has been sticking lately, chances are the school has noticed that the times are often off.
 
And running off oil pressure is just dumb. Every hobbs I've ever seen has been either running with the master, squat switch, or wind driven.


Where do you rent?

I'd love a hobbs that was run by the master, I hate all that radio chatter anyway.
 
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