Jump to content

ForeFlight Logbook Times


Recommended Posts

Does anyone use the ForeFlight Logbook flight times as they automatically generate? I'd like to, but they always seem a bit high. Then again, I don't have a Hobbs. I've been logging flight time by tach time so I suppose any other method is going to seem high. Has anyone compared ForeFlight logbook time to Hobbs?

I really don't want to get into using a stopwatch.

Link to comment
Share on other sites

I was corrected here on MS to change how I log. I was incorrectly instructed on how to log for years. You log when the aircraft is operating under its own power. So count startup to shutdown. ForeFlight for me is 50/50 accurate. It’s usually a tad high. I use my stopwatch on my iPhone.


Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

I use the flight time from my EDM900. Every so often, I download the data and upload it to my SavvyAnalysis account. That has a "duration" column that seems to be much closer to reality than ForeFlight. Then I update my ForeFlight log book. 

I'm certainly not about to pull out a stopwatch. But then logged flight time isn't all that important to me.

  • Like 1
Link to comment
Share on other sites

5 minutes ago, gsxrpilot said:

I use the flight time from my EDM900. Every so often, I download the data and upload it to my SavvyAnalysis account. That has a "duration" column that seems to be much closer to reality than ForeFlight. Then I update my ForeFlight log book. 

Had not thought of using the EDM flight time, but just checked the last four flights between the Savvy uploaded time and the ForeFlight times. They are the same in total, and vary by less than 5 minutes on each. I will use that as a cross check from now on. Thanks, Paul!

  • Like 1
Link to comment
Share on other sites

Back in the day...

Flight time was considered from the time the plane started rolling the tires under its own power, to the time it stopped rolling the tires under its own power...

So the flight instructors were interested in starting the engine, allowing the plane to move, then perform a brake test....

All the engine time after that was logged...

 

A bunch of inaccuracy occurs when you have a long taxi time before T/O...

  • any tach time is based on rpms of the engine... they are revolution counters.   taxiing anywhere over idle speed leads to fast ground speeds...
  • Mooneys with hour meters may have an oil pressure switch that starts the clock when the oil pressure comes up.  Counting time while standing still... prior to motion...
  • hour meters are nice, they don’t count engine revolutions...  it is important to know what switches them on...
  • an air pressure switch and an hour meter combination won’t capture the taxi time...
  • Some flight schools used to connect the hour meter to the master switch... starting the clock a bit early...

A fully integrated JPI has the opportunity to know a lot of detail...

  • it knows movement when connected to a WAAS gps...
  • it knows oil pressure for knowing the engine is running...
  • it counts time in seconds... 
  • it even counts fuel needed to get to your destination...
  • what it does with all this information, is log it in a file...

My logging requirements are relatively simple...

  • Aircraft maintenance
  • Insurance wants to see the previous year’s experience

Other sources of  hour logging that are available...

  • ClouAhoy an app that is great at logging flight maneuvers also logs the flight time in standard ways... using a WAAS source is best.
  • WingX has some ability to log flights as well...
  • remembering to be connected and turned on, can throw a wrench in the plan.

Some incomplete thoughts of a PP... not a time traveler...

Best regards,

-a-

Link to comment
Share on other sites

I've had FF time be 0.5 hr higher than my tach on flights before.  I have a JPI700 which doesn't log time, but I do have a hobbs/tach (not sure which one is installed) time in the back of my plane.  I've been going with the hobbs/tach then realized the FF time is start/stop.   I need more hours in my Bravo so sometimes I'll just use the average of the two.

Link to comment
Share on other sites

I wonder when JPI monitors start logging.  It doesn't seem to log when I have the motor off, but I do not have MP or RPM sensors, nor does it get GPS data, so I wonder if it waits for CHT's or EGT's to come up to a certain level before it starts recording

Link to comment
Share on other sites

I find that my ForeFlight time is pretty close to the hobbs for me and checking my hobbs is such a pain based on where Mooney put it.  For those not aware, the clock in the bravo (or maybe just my plane!) is in the left side of the passenger footwell.  I literally need to get on my stomach from the wing walk and use a flashlight to get the reading!

Link to comment
Share on other sites

3 minutes ago, Davidv said:

I find that my ForeFlight time is pretty close to the hobbs for me and checking my hobbs is such a pain based on where Mooney put it.  For those not aware, the clock in the bravo (or maybe just my plane!) is in the left side of the passenger footwell.  I literally need to get on my stomach from the wing walk and use a flashlight to get the reading!

Interesting...on my Bravo it's on the back wall in the luggage area...right below the upper storage compartment.

  • Like 1
Link to comment
Share on other sites

3 hours ago, jaylw314 said:

I wonder when JPI monitors start logging.  It doesn't seem to log when I have the motor off, but I do not have MP or RPM sensors, nor does it get GPS data, so I wonder if it waits for CHT's or EGT's to come up to a certain level before it starts recording

Expect when the electricity is delivered to the device... JPI comes alive and runs through its start-up sequence...

I believe, mine comes on with the avionics master...

Glass panel planes typically start logging data with the master switch...

The JPI is built robust enough to handle start-up surges of electricity...

PP thoughts only as usual...

Best regards,

-a-

  • Like 1
Link to comment
Share on other sites

According 14 CFR Part 1.1, Flight time means: 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. So, taxi time counts if you go flying. 

  • Like 1
Link to comment
Share on other sites

23 hours ago, jaylw314 said:
19 hours ago, carusoam said:

Expect when the electricity is delivered to the device... JPI comes alive and runs through its start-up sequence...

I believe, mine comes on with the avionics master...

Glass panel planes typically start logging data with the master switch...

The JPI is built robust enough to handle start-up surges of electricity...

PP thoughts only as usual...

Best regards,

-a-

I wonder when JPI monitors start logging.  It doesn't seem to log when I have the motor off, but I do not have MP or RPM sensors, nor does it get GPS data, so I wonder if it waits for CHT's or EGT's to come up to a certain level before it starts recording

At least on my JPI EDM900, all the recordings begin and end with EGTs in the 1000-1100 range and rpms in a wider 600-1100 range.  I suspect it is using evidence of sustained combustion based on EGT >1000 as the basis for starting and stopping data logging.

  • Like 2
Link to comment
Share on other sites

At least on my JPI EDM900, all the recordings begin and end with EGTs in the 1000-1100 range and rpms in a wider 600-1100 range.  I suspect it is using evidence of sustained combustion based on EGT >1000 as the basis for starting and stopping data logging.

Not on my 900:

0952a6dd6fc1b07da96eb86d646e3728.jpg

Maybe 500° for EGT, but I would hope RPM would be used?

 

 

Tom

  • Like 1
Link to comment
Share on other sites

30 minutes ago, ArtVandelay said:

Not on my 900:

Maybe 500° for EGT, but I would hope RPM would be used?

Tom

Huh, clearly a difference on yours. I checked multiple flights.  Maybe different firmware?  I have mine set to max sampling rate, so its not that.

image.thumb.png.a91b172fb145139cab23332a72621ec6.png

Edited by DXB
  • Like 1
Link to comment
Share on other sites

 

35 minutes ago, ArtVandelay said:

Not on my 900:

0952a6dd6fc1b07da96eb86d646e3728.jpg

Maybe 500° for EGT, but I would hope RPM would be used?

 

 

Tom

I believe RPM is correct on the Primary units, although not necessarily the Non-primary units. Although I am not 100% certain, I know on the certified Primary units, TACH time begins when RPM goes from 0 to 1000 rpm (factory default setting) to activate it and I believe Hobbs time is also activated at the same time.

But Non-primary units, which are wired into the Avionics buss I assume are activated when powered up which 99% of the time is after engine start. By then EGTs will be higher. 

For purposes of logging flight time, any Garmin (and I assume Avidyne) GPS makes this trivial. Just set the one of the timers to activate at "power on" and note the time just before shutdown. That's going to be within a minute of the traditional Hobbs meter that vast majority of us used for both logging and paying for aircraft rental time which was activated by oil pressure in most rental aircraft.

Using tach time, or the equivalent Mooney hour meter, intended for maintenance tracking,  is robbing yourself of total time. By about an average of 0.2 for each flight in my a/c. 

Edited by kortopates
  • Like 3
Link to comment
Share on other sites

20 hours ago, PT20J said:

According 14 CFR Part 1.1, Flight time means: 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. So, taxi time counts if you go flying. 

"comes to rest after landing."  I wonder how that is interpreted.  I landed at PDX once and it took ground about 30 minutes to taxi us around to the GA terminal.  I wonder if I should have subtracted that time from my flight time?

Link to comment
Share on other sites

I think it all counts towards total time in the way that I interpret the regulation.  If anything, every flight school is overestimating time by using the Hobbs alone since it’s activated in a lot of planes by the rise of oil pressure (when the aircraft turns on and off).  The time that is spent in warm up, receiving clearances, ect before the aircraft moves is being counted towards total logbook time.  

This is why I think an accurate ForeFlight/CloudAhoy log (or a stopwatch if you like) most closely mirrors the regulation because it should theoretically start when the plane begins to move and stop when the plane ultimately comes to rest.  I’ve looked at several of my detailed tracks in the app and it very closely (down to what looks like a few feet) seems to capture where the plane started moving to where it ultimately stopped.  You just need to be careful that the GPS source is a good one and in the plane when recording starts. I’ve had it accidentally also record from my iPhone and it shows my walk from the car to the plane.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.