Yet...another, another logbook question

John_Mitchell

John_Mitchell

Well-Known Member
I have been flying my buddy's 182 for a few months now and have about 50 hours in it. I went flying with him last week as his Safety Pilot for some ILS approaches (he let me do one under the hood and I actually nailed the approach, it was really awesome). Anyway, when we were securing the plane, we were filling out his plane log and our logbooks and I went to put down the time in my logbook and he noticed that I was logging the actual time indicated by his meter. Problem is, his plane doesn't have Hobbs, just a tach. He told me that a pilot is actually allowed to log tach time X 1.2 in their logbook. I haven't looked up the regs yet, for one reason quite frankly, I wouldn't know where to look. Anyway, are any of you familiar with this regulation? Furthermore, if I am allowed to log Tach Time X 1.2, would any of you suggest I make a one time entry to update my flight time to reflect the additional 0.2 hours for every hour I have already logged?

Also, here is another logbook question... I received flight instruction in a Robinson R22 helo today during an intro flight. Yes, I am considering the "dark-side"..hehehe. Anyway, I logged the time in my logbook, but obviously did keep it separate insofar as category/class etc... The furthest right side column in my Gleim logbook is "Total Flight Time". I entered the helo time into this column as well. My page is now full and I just noticed that if I add this helo time into my cumulative Total Time, my TT will be mixed apples and oranges. Any suggestions on how to not mix up my bag of fruit? Or does it matter?

Thanks for your wise input!
 
As I understand it, hobbs meters start clicking either when the battery master is on or when the engine is started (depending on the plane). They then turn over at a constant rate until either the engine is switched off, or the batter master (again, depending on the plane).

The tach meter starts turning when the engine is started, but doesn't turn at a constant rate. The rate it turns varies depending on the RPM of the engine. Faster RPM=faster turn rate. Thus the tach time is usually .2-.3 less than the hobbs time (due to start up, taxi, flight at low power settings, etc.) when the tach timer isn't turning at the "full rate". That's how I understand it... anyone else agree or disagree??

As for the heli time... if I was going to be primarily flying fixed wing, I'd probably leave it out of my TT. But that's just me...
 
Yes, the hobbs meter is usually either activated by the master or it can be activated by oil pressure running into a pressure switch and therefore only running while the engine is too.

The tach has a predetermined rpm per hour, so if you fly at a high rpm for one hour it will show one hour before one "actual hour".

It all depends on what kind of flying you do, it is usually close to 1.2x tach time during normal XC flying (for some planes at least).

I have seperate logbooks for gliders and airplanes, this way you always know how much you got of each and if you need to know the total time you just add the two big numbers up...
 
The above description is how I always understood hobbs vs tach too.
I used to fly a few planes that were hobbs free. I recall a lot of guys did the 1.2 or 1.3 thing. I think for the most part I just used my watch. Seemed more accurate. (Though if I recall the tach w/multiplier was not that far off most the time.) If it has a GPS see if there is a page that tracks the time, that could work too.

I don't believe there are any regs regarding that one. Someone who is more bored than me might want to look that up.
 
There is no guidance in the regs for hobbs/tach time.

The proper way to log flight time is to to look at the time when you release the brakes, and look at the time when you come to a complete stop after the flight.
 
flynik said:
Yes, the hobbs meter is usually either activated by the master or it can be activated by oil pressure running into a pressure switch and therefore only running while the engine is too.

The tach has a predetermined rpm per hour, so if you fly at a high rpm for one hour it will show one hour before one "actual hour".

It all depends on what kind of flying you do, it is usually close to 1.2x tach time during normal XC flying (for some planes at least).

I have seperate logbooks for gliders and airplanes, this way you always know how much you got of each and if you need to know the total time you just add the two big numbers up...
Click to expand...
some hobbs work off vibration as well
 
I've heard of the 1.2 thing, but at this point I would not go back to correct it. As for the helo, TT is TT. Log it. Everybody (ie airline) has their own opinion, so just report what they ask for.
 
mtsu_av8er said:
There is no guidance in the regs for hobbs/tach time.

The proper way to log flight time is to to look at the time when you release the brakes, and look at the time when you come to a complete stop after the flight.
Click to expand...
Bingo.

But most folks log Hobbs and many use a factor when logging tach. I've heard of both 1.15 and 1.2 as an average. If you compare tach and Hobbs readings over a few flights in an aircraft that has both, I think they work out as an approximation, and only the truly anal really care.

John, on your second question, from a logging standpoint it doesn't matter. It only matters those time when you need to break it down and get an airplane vs a helicopter total. But that just as true if you need to run separate totals for single engine and multi engine airplanes or PIC cross country flights opposed to when you were not entitled to log PIC or a multitude of other subtotals of information in your logbook.

Once you comply with 61.51 for logging the time, how much further you break it down and what extra columns you create is a piratical question rather than a regulatory one - and a great reason for an electronic logbook.
 
MidlifeFlyer said:
Bingo.

But most folks log Hobbs and many use a factor when logging tach. I've heard of both 1.15 and 1.2 as an average. If you compare tach and Hobbs readings over a few flights in an aircraft that has both, I think they work out as an approximation, and only the truly anal really care.

John, on your second question, from a logging standpoint it doesn't matter. It only matters those time when you need to break it down and get an airplane vs a helicopter total. But that just as true if you need to run separate totals for single engine and multi engine airplanes or PIC cross country flights opposed to when you were not entitled to log PIC or a multitude of other subtotals of information in your logbook.

Once you comply with 61.51 for logging the time, how much further you break it down and what extra columns you create is a piratical question rather than a regulatory one - and a great reason for an electronic logbook.
Click to expand...
www.logshare.com works great!
 
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