Fore flight Log time vs Hobbs - Logging

Somedudeintn

Somedudeintn

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somedudeintn
Does anyone here use the the automatic Foreflight logs as the time you put in your logbook?

I've always just used the Hobbs but the Hobbs for my flight today was 3.2. Foreflight showed 1.7 on the way up and 1.8 on the way back. That seems like a pretty big difference to me.

I'm thinking I may need to use a stopwatch next flight to get my true time from when the airplane moves under its own power to when it stops engine is shut down.

Anyone else notice a discrepancy between these numbers? What do you use in your logbook?
 
No Hobbs in our plane, so I've modified my starting engine and shutdown checklists to remind me to start/stop the timer on my watch. I have Forefight Logbook, but have never used it (or even really looked at it) since I'm a happy user of MyFlightbook.
 
mjburian said:
No Hobbs in our plane, so I've modified my starting engine and shutdown checklists to remind me to start/stop the timer on my watch. I have Forefight Logbook, but have never used it (or even really looked at it) since I'm a happy user of MyFlightbook.
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I also use myflightbook and love it! I have Foreflight set to automatically log and just noticed the times it was showing from the logs to import into the FF logbook.

Looking back at my flights in another plane, most are +/- 0.1 Hobbs vs FF, although one was off by about 0.3 on a longer flight.
 
I'm also a look at my watch and MFB sort.
 
Look at my watch and note the start and stop time. It has always been spot on with the Hobbs. That is the time that goes in my logbook. I don't know the parameters of when FF starts and stops timing.
 
My current airplane has a tach only, no Hobbs. Honestly, I take the tach time and kind of guesstimate how long the flight really was and log that. You don't need to be accurate to the minute. An extra .2 here, a short .2 there, just be reasonably close.
 
Since no one is going to give a rat's behind about a tenth or two in the long run, nothing beats a Mickey Mouse watch. The only person who ever checked my logbooks was the FAA inspector who gave me my ATP ride in 1977....don't recall him obsessing over time I logged in 1964.

Bob Gardner
 
One of the things that I am sure many pilots guesstimate in their logbooks is IMC time. On a 2.5 hour trip in and out of the clouds here and there only adds up to a tenth here and there. There is no IMC meter they I'm aware of so just ball park it and never gets challenged!
 
While nobody's probably going to question the times, if someone mentioned to me that they log the times Foreflight gives them, I'd make sure they can explain to me what Foreflight uses for start and stop times.

Anybody know?
 
MauleSkinner said:
While nobody's probably going to question the times, if someone mentioned to me that they log the times Foreflight gives them, I'd make sure they can explain to me what Foreflight uses for start and stop times.

Anybody know?
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I am not certain but my log book entries seem to be usually wheels up to wheels down times. Probably use GPS data to determine accelerated speed and increase in altitude and the reverse. But then I just add the Hobbs start and end times and the true time updates. I do now that my Hobbs time is always more.
 
Somedudeintn said:
I've always just used the Hobbs but the Hobbs for my flight today was 3.2. Foreflight showed 1.7 on the way up and 1.8 on the way back. That seems like a pretty big difference to me.
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it is possible that the Hobbs is not working right. I have had two Hobbs meters break over the years. On the first, it gradually slowed down over a few flights until I noticed that it recorded about 0.5 hours for a 1 hour flight. No way that could be explained just by rounding. On the second, it just plain stopped in mid flight.

I'm thinking I may need to use a stopwatch next flight to get my true time from when the airplane moves under its own power to when it stops engine is shut down.
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No need for a stopwatch, just note takeoff time and landing time and subtract.
 
I use FF (the recording not the logbook) start/stop is on my checklist. My plane has a tach so this is my best option.
 
Somedudeintn said:
Does anyone here use the the automatic Foreflight logs as the time you put in your logbook?

I've always just used the Hobbs but the Hobbs for my flight today was 3.2. Foreflight showed 1.7 on the way up and 1.8 on the way back. That seems like a pretty big difference to me.

I'm thinking I may need to use a stopwatch next flight to get my true time from when the airplane moves under its own power to when it stops engine is shut down.

Anyone else notice a discrepancy between these numbers? What do you use in your logbook?
Click to expand...

Sounds like a fancy way of doing a simple task, beside you should be timing your flights anyways.

I use my watch chrono, or sometimes the stopwatch on my iPhone, and I back ether one of those up with my GTX transponder stop watch.

With the way I fly, where I fly/float/stop, and with me wanting to log every second the prop is turning and/or the plane is moving, foreflight doesn't always "get it". Also there are lots of little flights I'll make where I don't really need foreflight running on my phone eating my battery, and I don't bring my iPad for every little flight.
 
James331 said:
Sounds like a fancy way of doing a simple task, beside you should be timing your flights anyways.

I use my watch chrono, or sometimes the stopwatch on my iPhone, and I back ether one of those up with my GTX transponder stop watch.

With the way I fly, where I fly/float/stop, and with me wanting to log every second the prop is turning and/or the plane is moving, foreflight doesn't always "get it". Also there are lots of little flights I'll make where I don't really need foreflight running on my phone eating my battery, and I don't bring my iPad for every little flight.
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I usually do time takeoff to shutdown (write down the times), but never startup to shutdown. I'll have to start writing down start time too.
 
I use the hobbs time. FF logbook always is a little longer. I was thinking it might correspond to the time the Stratus-2s is turned on, but I don't know for sure.
 
The three planes I fly most have no Hobbs. Primarily I use Tach * 1.2

Somedudeintn said:
I'm thinking I may need to use a stopwatch next flight to get my true time from when the airplane moves under its own power to when it stops engine is shut down.
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Shouldn't it be engine start to engine shut down? That's how everyone is being charged for rental (tach or hobbs) so if you bought it, log it.

Some other thread we can talk about where the Hobbs wired. Some are from master switch on. Others are from the alternator so it's actual engine running. Usually a small difference, unless you leave the master on to walk around and check the wingtip and tail lights, etc. But that's another days bunch of opinions.
 
rolivi said:
Shouldn't it be engine start to engine shut down? That's how everyone is being charged for rental (tach or hobbs) so if you bought it, log it.
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Not according to the FAA... but practically it's the same unless it takes you 6 minutes before start rolling

Flight time means:

(1) Pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing.

http://www.ecfr.gov/cgi-bin/text-idx?rgn=div8&node=14:1.0.1.1.1.0.1.1​
 
Well I start the engine and then IMMEDIATELY let off the brakes (not breaks) and then reapply them. How's that for movement under it's own power? I thought that was done to test the brakes but if it's for logbook compliance - all the better :)

"Comes to rest after landing" I think is engine stop. Plane still has work to do to get from the runway to the hangar. I guess I could try "Tower, Bugdestroyer 666 is done flying, send tugg to RW16L, over and out" :(
 
Confession: I don't test the brakes until after I confirm RPM, Oil Pressure, and Fuel Pressure. Not immediately, but nowhere close to .1 hrs.
 
rolivi said:
"Comes to rest after landing" I think is engine stop. Plane still has work to do to get from the runway to the hangar.
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So under these rules, it sounds like I quit being PIC the second I pull off the runway and stop to switch frequencies. In that case, I guess I'll start taking that time to pop open the booze and just kinda hope the plane taxis itself.
 
The plane will move when the engine is started, even with the brakes on.

Also ask yourself this, if you pranged something, would the insurance company consider it a "in motion" claim?? Would you be considered PIC of the plane at the time?

If I would be guilty of being PIC, you bet I'm going to log it.
 
James331 said:
The plane will move when the engine is started, even with the brakes on.

Also ask yourself this, if you pranged something, would the insurance company consider it a "in motion" claim?? Would you be considered PIC of the plane at the time?

If I would be guilty of being PIC, you bet I'm going to log it.
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Since when does the insurance company dictate FAA definitions?
 
Somedudeintn said:
Not according to the FAA... but practically it's the same unless it takes you 6 minutes before start rolling

Flight time means:

(1) Pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing.

http://www.ecfr.gov/cgi-bin/text-idx?rgn=div8&node=14:1.0.1.1.1.0.1.1​
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IMO, the plane starts moving when the fast spinny thing up front starts spinning and doesn't come to rest until the fast spinny thing up front stops. Between those two times, it's still moving under its own power and not at all at rest.
 
Update:

I timed a flight last week in the same plane and calculated the time as 1.8.

Hobbs read 1.7.

Foreflight told me it was 2.2. Maybe foreflight starts the clock as soon as I push the plane out of the hangar and doesn't stop until its back in.

At any rate, I now know not to trust the foreflight automatic time, although I wonder how many pilots just blindly accept the more generous time for their logbooks.
 
On message boards, people can take any simple concept and start a whole discussion about it, including citing FAA rules, etc.

Seems pretty simple to me, when I go back to return the plane, I get charged for 2.2 hours. I log 2.2 hours in my log book.

I don't think the FAA cares about the extra 0.3 difference from start up to "movement under its own power for the purpose of flight".
 
Somedudeintn said:
At any rate, I now know not to trust the foreflight automatic time, although I wonder how many pilots just blindly accept the more generous time for their logbooks.
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That's why I don't use Foreflight time. It seems to always be at least 0.5 more than my calculated time and Hobbs time.
 
Somedudeintn said:
Since when does the insurance company dictate FAA definitions?
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Ok fair enough.

Put a micrometer on the main tire, start the engine, is the reading the same, nope.

Start the engine, have someone walk into the prop, tell the Feds you weren't PIC because the plane haven't yet "moved", they'll probably 91.13 you just for making that comment.

Once your engine is running, you're PIC, you're taking the risk, your ticket is on the line, log the time.

You'll also find most all working pilots log engine start to stop.
 
James331 said:
Ok fair enough.

Put a micrometer on the main tire, start the engine, is the reading the same, nope.

Start the engine, have someone walk into the prop, tell the Feds you weren't PIC because the plane haven't yet "moved", they'll probably 91.13 you just for making that comment.

Once your engine is running, you're PIC, you're taking the risk, your ticket is on the line, log the time.

You'll also find most all working pilots log engine start to stop.
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I fully agree
 
I log the time just before I roll across the hold-short line on my knee board, and then after I cross the hold-short line when clearing the runway. To me, that is the exact flight time. It's not that I care about being that accurate. It's more that I'm trying to develop the habit of being more precise in everything that I do when flying. Entering the flight in my logbook is on my close-down checklist. (Although, sometimes I just take the page from my knee board home and do it there!)
 
Somedudeintn said:
Does anyone here use the the automatic Foreflight logs as the time you put in your logbook?

I've always just used the Hobbs but the Hobbs for my flight today was 3.2. Foreflight showed 1.7 on the way up and 1.8 on the way back. That seems like a pretty big difference to me.

I'm thinking I may need to use a stopwatch next flight to get my true time from when the airplane moves under its own power to when it stops engine is shut down.

Anyone else notice a discrepancy between these numbers? What do you use in your logbook?
Click to expand...

There's no reg that says you have to use a Hobbs. My old instructor would simply look at his watch and say, yeah, that was about 1.7 today. Uh...okay.
 
Different scenario but same concept. When you start flying and tracking instrument time there is no cloud meter. You just have to ball park it. And then there is the whole tenth rounding thing. A few minutes here and there add up to a lot over a year!!
 
mulligan said:
Different scenario but same concept. When you start flying and tracking instrument time there is no cloud meter. You just have to ball park it. And then there is the whole tenth rounding thing. A few minutes here and there add up to a lot over a year!!
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I'll start working on my cloudometer. :)
 
James331 said:
Ok fair enough.

Put a micrometer on the main tire, start the engine, is the reading the same, nope.

Start the engine, have someone walk into the prop, tell the Feds you weren't PIC because the plane haven't yet "moved", they'll probably 91.13 you just for making that comment.

Once your engine is running, you're PIC, you're taking the risk, your ticket is on the line, log the time.

You'll also find most all working pilots log engine start to stop.
Click to expand...

Agree 100%. As far as I'm concerned, as soon as your head leans to the window and yells "clear," then you turn the key, you are directly responsible for everything that occurs as PIC.
 
As soon as I start my engine, I do a slow speed brake test that way I can use the hobbs as my time logged since the aircraft started moving when the engine was turned on.
 
There was a thread on the AOPA Members group on facebook that made me chuckle. The guy was asking if he could count his pre flight walk around as flight time. I'm not sure if he was serious or not.
 
jordane93 said:
There was a thread on the AOPA Members group on facebook that made me chuckle. The guy was asking if he could count his pre flight walk around as flight time. I'm not sure if he was serious or not.
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Well if you preflight properly you are technically manipulating the flight controls so makes me think he or she is not so dumb
 
Foreflight time is very generous, even if you MANUALLY start and stop the recording.
 
If you have foreflight set to start the timer manually, then it starts on lift off but automatically adds (some time for taxi etc). I can't remember if that's 15 or 30 mins.

I queried them about this once, and that's just the way it is designed.

I've put starting and stopping the foreflight timer on my checklist now, and the figures are accurate.
 
This will probably start some FF vs GP war...but I noticed in Pilot you can specify the extra time to add to the auto logged time when speed & altitude meet the liftoff criteria. Does Foreflight have something similar? I have the Garmin Pilot set to add 0.1 and it works pretty well.
 
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