Hobbs Meter

[SpinAware]

I flew with a student on C-172 airplane yesterday.

We completed a x-country flight with exactly 50 nmiles (to & fro) at about 95 Kts. The entire flight was at low altitude enroute and calm wind condition. At the end of the air-exercise, the hobbs meter shows 2.4hrs! This is the first time, I've encountered such a hobbs meter running faster than usual!

Side-story...

The flight school is not doing well and has about 3 foreign students pathetically. The school has eight airplanes, six are to be scrapped but only two (one C172 & one C152) are serviceable. The school owner is greedy and tried to scam the students. And there are many stories to share ...

Nonetheless, I have a technical query for the A&P Mechanic/Technician - I highly suspected the hobbs meter is manipulated. Is that possible?

 

[ppragman]

I flew with a student on C-172 airplane yesterday.

We completed a x-country flight with exactly 50 nmiles (to & fro) at about 95 Kts. The entire flight was at low altitude enroute and calm wind condition. At the end of the air-exercise, the hobbs meter shows 2.4hrs! This is the first time, I've encountered such a hobbs meter running faster than usual!

Side-story...

The flight school is not doing well and has about 3 foreign students pathetically. The school has eight airplanes, six are to be scrapped but only two (one C172 & one C152) are serviceable. The school owner is greedy and tried to scam the students. And there are many stories to share ...

Nonetheless, I have a technical query for the A&P Mechanic/Technician - I highly suspected the hobbs meter is manipulated. Is that possible?

I once worked at a place that had a switch to deactivate the Hobbs, coincidentally it would always be flipped after the owner flew it. So I wouldn't be surprised if the opposite was true.

 

[Roger Roger]

I have never heard of a Hobbs running faster than usual.

I have seen them running when they shouldn’t be for various reasons, and I have seen them accumulate time during maintenance because of how they are designed.

 

[trafficinsight]

I don't know of any way to get the Hobbs to turn faster other than perhaps a 12 v Hobbs in a 24 volt airplane. Was it a new Hobbs?

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[Roger Roger]

I don't know of any way to get the Hobbs to turn faster other than perhaps a 12 v Hobbs in a 24 volt airplane. Was it a new Hobbs?

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I thought most of the Hobbs meters are like 6-32VDC?

 

[trafficinsight]

I thought most of the Hobbs meters are like 6-32VDC?

That's what I thought too, couldn't remember.

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[killbilly]

I have never heard of a Hobbs running faster than usual.

I have seen them running when they shouldn’t be for various reasons, and I have seen them accumulate time during maintenance because of how they are designed.

One of the airplanes in the fleet I work with had a major disparity between the Hobbs and the tach last summer (like, huge) but I can't remember which one the problem was - I think the tach was the problem.

 

[Roger Roger]

One of the airplanes in the fleet I work with had a major disparity between the Hobbs and the tach last summer (like, huge) but I can't remember which one the problem was - I think the tach was the problem.

Yeah, that would make sense.

 

[trafficinsight]

One of the airplanes in the fleet I work with had a major disparity between the Hobbs and the tach last summer (like, huge) but I can't remember which one the problem was - I think the tach was the problem.

Tach runs faster or slower based on engine RPM

1:1 is usually 2500

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[Roger Roger]

That's what I thought too, couldn't remember.

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I think the ones I’ve installed/replaced have all been. But it’s been a while so I could be wrong.

Side note, whenever I installed an air Hobbs, I would use an in-line fuse behind the panel for circuit protection. Want to disable the Hobbs? Great, hope you enjoy flying with the master off.

 

[SpinAware]

I don't know of any way to get the Hobbs to turn faster other than perhaps a 12 v Hobbs in a 24 volt airplane. Was it a new Hobbs?

C172 M model.
Hobbs meter looks old to me.

 

[SpinAware]

One of the airplanes in the fleet I work with had a major disparity between the Hobbs and the tach last summer (like, huge) but I can't remember which one the problem was - I think the tach was the problem.

Student pays according to Hobbs time. So, Hobbs meter reading mean alot.
Usually, tach time, we don't care. So long, it it within 100hrs.

 

[trafficinsight]

C172 M model.
Hobbs meter looks old to me.

I'm going to guess that either you or your student didn't check the the out time on the Hobbs close enough.

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[z987k]

I'm going to guess that either you or your student didn't check the the out time on the Hobbs close enough.

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Or compare it to the tach time.

 

[SpinAware]

Or compare it to the tach time.

I'm going to guess that either you or your student didn't check the the out time on the Hobbs close enough.

I have >1000hours. Do you think I am stupid?

I have my habit of checking things that most people do not have!

 

[SpinAware]

Anybody able to answer my query about manipulation of hobbs meter?

 

[trafficinsight]

I have >1000hours. Do you think I am stupid?

I have my habit of checking things that most people do not have!

Hahahahahahahaha

> 1000 hours? You're about 1/4 as stupid as I am




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[z987k]

I have >1000hours. Do you think I am stupid?

I have my habit of checking things that most people do not have!

So then the tach is pretty close to the hobbs then?

 

[SpinAware]

Hahahahahahahaha

> 1000 hours? You're about 1/4 as stupid as I am

Then, you must be a bloody idiot!

 

[SpinAware]

So then the tach is pretty close to the hobbs then?

Not really that close.