ForeFlight Pro Disappointment

Lance F

Lance F

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Lance F
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I just sprung for the FF Pro version mainly to get the georeferenced taxi diagrams. Tried it the last couple of days and am not impressed. I've been at three airports so far and at two of them I found the offset to be unacceptable.
In this screenshot you see the plane taxiing in the grass. I guess at this airport KLZU it's not a big deal, but Friday I was on Delta and followed our taxi at OHare. There this displacement showed us on a taxiway parallel to the one we really were on. That is big time serious if you use this thing to help you be where you should.
Anyone else monitoring this with better results? Did I just waste 60 bucks?
 
I don't have foreflight, but I have heard nothing but excellent stuff about their response to customer feedback. Did you run it by them?
 
I don't have ForeFlight either but I can tell you that the much higher dollar Jepp taxi charts are off sometimes too. I've never seen them off far enough to put us on another taxiway though.
 
We were on J and the chart showed us showed us right in the middle of T. Got my attention. You can see I have 5M accuracy which is as good as it gets.
 
Matt is right. Foreflight will most definitely want to hear your feedback. More importantly, I feel quite confident that they will act on it. They are a CLASS organization.
 
Email sent to FF. I'll let you know what they say.
 
It will be interesting to hear what they say. I bet there is a certain amount of fudge in airport diagrams and that georeferencing a non scale drawing can be tough.
 
I'm going to take a wild guess that the taxi charts may be off. I do know for a fact some of the buildings are misplaced and mislabeled at LZU.
 
FF blames it on the iPhone GPS. Fast response but not very satisfying. BTW the picture was taken in an RV12 which has a complete clear canopy. So the view of satellites couldn't be better.

Email repose from FF follows

The GPS in the iPhone isn't "aviation grade". *A lot depends on where you have the phone positioned and how clear of a view to the satellites that position provides. *You may want to look into an external GPS. *I have included a link to our blog which discusses them.

http://blog.foreflight.com/2010/11/09/external-ipad-gps-receivers-for-foreflight-hd/

Take a look at that and let us know if you have any questions -- we're happy to help!
 
Well my IPad2 GPS show me sitting on my lot right where I am....I didn't spring for the georefed charts...I have Safe Taxi in the dash...
 
Lance, did you have the 3G disabled on your iPad? If not, the iPad might have been trying to determine position by triangulating from cell sites. I use a fitness tracking app on the iPhone, and if 3G is not disabled the track of my morning walk looks like a drunken sailor, weaving across streets, through buildings, etc.

Also, as mentioned above, NOS charts are anything but perfect. On the Seattle sectional, my home field is shown about two miles north of its actual position. You can be on downwind north of the field, and on the georeferenced chart in Foreflight it looks like you're south of the field - but the GPS plot is accurate.
 
Pilawt said:
Lance, did you have the 3G disabled on your iPad? If not, the iPad might have been trying to determine position by triangulating from cell sites. I use a fitness tracking app on the iPhone, and if 3G is not disabled the track of my morning walk looks like a drunken sailor, weaving across streets, through buildings, etc.

Also, as mentioned above, NOS charts are anything but perfect. On the Seattle sectional, my home field is shown about two miles north of its actual position. You can be on downwind north of the field, and on the georeferenced chart in Foreflight it looks like you're south of the field - but the GPS plot is accurate.
Click to expand...

That's my guess, turn off the 3G and let the GPS only work.
I have the iPad, I've found the attached Bad Elf is more accurate than the internal GPS.
 
I'm using the DUAL XGPS 150 external Bluetooth GPS with my iPad, and turn off the 3G when flying. It's highly accurate, Lance. I think FF is correct about the signal you were getting.

Were you in an airliner? If so, the geometry of satellites you were able to receive through the window on one side of the airplane may not have been as good as if you were getting full spectrum across the hemisphere of the sky.
 
I've had no issues with foreflight's position depictions.
 
Lance, can you find someone else who uses the airport and an iPad or iPhone? Maybe someone who is using one of the external GPS. Just to compare and see. I know that the places I've been, my location in FF has been spot on (GNS5780 bluetooth GPS)
 
BillTIZ said:
That's my guess, turn off the 3G and let the GPS only work.
I have the iPad, I've found the attached Bad Elf is more accurate than the internal GPS.
Click to expand...

My understanding was that the internal GPS was tied to the 3g chip(at least on the ipad). If you turn off 3g, then you've turned off the internal GPS. I've got an ipad2 with 3g, but no 3g data plan has been activated on it, but I still have to have 3g turned on for internal GPS to work.

All this talk about ipads may be a moot point though because the OP was using an iphone. I don't have an iphone so I don't know if you can disable 3g or not, or if you can use any external GPS devices with it.
 
Lance F said:
We were on J and the chart showed us showed us right in the middle of T. Got my attention. You can see I have 5M accuracy which is as good as it gets.
Click to expand...
It's hard to say at this point whether this was GPS position or cartographic error. But FWIW, that "5M" position accuracy indication really only means that the geometry of the satellites being tracked should provide a solution that accurate if the reception is perfect. It is not a true measure of the calculated position's accuracy. I have seen a reported 5M accuracy on my iPad2 operating inside my house (signals penetrating the roof) while the depicted position varied 20-50M over time. Virtually all automotive GPS devices have algorithms that "favor" a position on a road as a means of augmenting the typical position inaccuracies of their GPS solutions.
 
Good grief. I was on a plane with a plexiglass bubble canopy , gps was on, 3G was on and the "accuracy" showed 5 M. That should be as good as it gets. It was good to do this testing where it didn't count. I know to be a little careful when using these georeferenced charts in critical situations.

A separate gps antenna is not a good solution for me. I also have this on my iPad 2 and will be trying this Pro version on it this week.
 
bfergie10 said:
All this talk about ipads may be a moot point though because the OP was using an iphone. I don't have an iphone so I don't know if you can disable 3g or not, or if you can use any external GPS devices with it.
Click to expand...
Roger all of that...

Lance F said:
Good grief. I was on a plane with a plexiglass bubble canopy , gps was on, 3G was on and the "accuracy" showed 5 M. That should be as good as it gets. It was good to do this testing where it didn't count. I know to be a little careful when using these georeferenced charts in critical situations.

A separate gps antenna is not a good solution for me. I also have this on my iPad 2 and will be trying this Pro version on it this week.
Click to expand...
Lance, let us know how that works out with the IPad2. I was thinking about getting the charts for fun but I will wait till I see what you say about it to decide...
 
The following is my perspective after serving for many years as a former senior avionics engineer for one of the world's largest airlines and as a private pilot:

This example highlights the true crux of the controversy that has raged for years over the use of non-certified gadgets in the cockpit. I personally use Foreflight on an iPad1 and can testify that it has transformed the way that I manage charted information both on the ground and in the air. I have purposefully opted not to subscribe to the service that places the aircraft on the plates and do not use the depiction of the aircraft on the low altitude and sectional charts to determine my position. I choose instead to use the certified panel for that and make an emphatic conscious decision to rely on the panel as the end of discussion authority on the matter of position.

It is important to make the decision of which information sources will have absolute precedence long before the engine is even running. Ambiguous information is never a good thing in the cockpit. Precious seconds must never be wasted on attempts to resolve conflicts of information sources in the air when such conflicts can be resolved by fiat on the ground.

It's bad enough when conflicting information is presented by two independent TSO'd systems like a panel system and a certified portable. In those cases I recommend a weighted vote in favor of the panel but if you think the portable may be more reliable for whatever reason then go ahead and make decisions with it in the air. In the worst case in that scenario you at least have a 50% chance of getting it right. Not so with non-certified equipment.

I love my iPad as an EFB but as a navigation system, especially in the slag, no thanks. I'm sticking with the panel even when it's nothing more than a handful of those electromechanical WW2 vintage technology gizmos.

As for taxi situation awareness, what's wrong with using airport signage? Failing that, I have never felt any shame or hesitation to ask for progressive taxi at unfamiliar fields and I have never had a ground controller berate me for asking.
 
bfergie10 said:
My understanding was that the internal GPS was tied to the 3g chip(at least on the ipad). If you turn off 3g, then you've turned off the internal GPS. .
Click to expand...
No you haven't. The GPS will operate independent of 3G. You turn off cellular data in the iPad settings.

FF has a video that covers a lot of the preflight activity that should be done with the iPad (including turning off cellular data). Everyone who flies with an iPad should watch it.

http://vimeo.com/29838619
 
I usually turn off 3G because in flight when out of cell range the device constantly searches for a signal and drains the battery more quickly. When on the ground and a 3G signal is in range, it is susceptible to location errors as described. The only advantage to having 3G on is occasionally being able to harvest some weather data enroute.
 
DrMack said:
The following is my perspective after serving for many years as a former senior avionics engineer for one of the world's largest airlines and as a private pilot:

.....


It's bad enough when conflicting information is presented by two independent TSO'd systems like a panel system and a certified portable.
Click to expand...
There's a certified portable? Manufacturer & model please, I want one!
 
DrMack said:
The following is my perspective after serving for many years as a former senior avionics engineer for one of the world's largest airlines and as a private pilot:

This example highlights the true crux of the controversy that has raged for years over the use of non-certified gadgets in the cockpit. I personally use Foreflight on an iPad1 and can testify that it has transformed the way that I manage charted information both on the ground and in the air. I have purposefully opted not to subscribe to the service that places the aircraft on the plates and do not use the depiction of the aircraft on the low altitude and sectional charts to determine my position. I choose instead to use the certified panel for that and make an emphatic conscious decision to rely on the panel as the end of discussion authority on the matter of position.

It is important to make the decision of which information sources will have absolute precedence long before the engine is even running. Ambiguous information is never a good thing in the cockpit. Precious seconds must never be wasted on attempts to resolve conflicts of information sources in the air when such conflicts can be resolved by fiat on the ground.

It's bad enough when conflicting information is presented by two independent TSO'd systems like a panel system and a certified portable. In those cases I recommend a weighted vote in favor of the panel but if you think the portable may be more reliable for whatever reason then go ahead and make decisions with it in the air. In the worst case in that scenario you at least have a 50% chance of getting it right. Not so with non-certified equipment.

I love my iPad as an EFB but as a navigation system, especially in the slag, no thanks. I'm sticking with the panel even when it's nothing more than a handful of those electromechanical WW2 vintage technology gizmos.

As for taxi situation awareness, what's wrong with using airport signage? Failing that, I have never felt any shame or hesitation to ask for progressive taxi at unfamiliar fields and I have never had a ground controller berate me for asking.
Click to expand...

As to a portable, my Garmin 696 was made for the job, and does as advertised. On the otherhand, it's a dedicated aviation GPS. And it can beat the old method of airport signage by a long shot......at unfamiliar fields.
 
murphey said:
There's a certified portable? Manufacturer & model please, I want one!
Click to expand...

Sorry, I was referring to certified EFBs. I don't know of any portable nav devices that conform to the TSOs for such.
 
bfergie10 said:
My understanding was that the internal GPS was tied to the 3g chip(at least on the ipad). If you turn off 3g, then you've turned off the internal GPS. I've got an ipad2 with 3g, but no 3g data plan has been activated on it, but I still have to have 3g turned on for internal GPS to work.

All this talk about ipads may be a moot point though because the OP was using an iphone. I don't have an iphone so I don't know if you can disable 3g or not, or if you can use any external GPS devices with it.
Click to expand...

My Gen 1 iPad, four recievers, Bluetooth, WiFi, 3G and GPS, go to "airplane mode" and all four are turned off. Turn WiFi and 3G off indendently and the GPS reciever remains active, I don't use Bluetooth and keep it turned off.
 
Lance F said:
Good grief. I was on a plane with a plexiglass bubble canopy , gps was on, 3G was on and the "accuracy" showed 5 M. That should be as good as it gets. It was good to do this testing where it didn't count. I know to be a little careful when using these georeferenced charts in critical situations.

A separate gps antenna is not a good solution for me. I also have this on my iPad 2 and will be trying this Pro version on it this week.
Click to expand...

I wouldn't put too much weight on the accuracy that you iPhone is reporting. The GPS broadcast interface specification defines something called User Range Accuracy (URA) that each satellite bradcasts. A reciever then implements an algorithm to convert the URA and the geometry of the satellites (DOP) into an estimate of the reciever position accuracy. Unfortunately, that algorithm presumes a certain level of measurement precision that the iPhone may not have.

I'll bet that FF has some idea of what it thinks the cartographic error is for that chart. Anything greater than that they are going to blame on your phone.
 
midlifeflyer said:
No you haven't. The GPS will operate independent of 3G. You turn off cellular data in the iPad settings.

FF has a video that covers a lot of the preflight activity that should be done with the iPad (including turning off cellular data). Everyone who flies with an iPad should watch it.

http://vimeo.com/29838619
Click to expand...

That discussion starts at about 10:10 in the video. But I'm dubious and here's why:

There is still rampant misunderstanding about assisted GPS and the iPad/iPhone. You might understand the issues but many people don't, and frankly, Foreflight folks could do a better job of explaining potential issues than they do.

I see no advantage to disabling your data signal to improve accuracy. There is no way that having a 3G signal could degrade anything other than your battery power and your sanity as chirping is heard in your intercom ;) As a user you should be attuned to clues that indicate that your location accuracy is degraded. Is your location icon pulsing? Yes: Your location is being determined by GPS. No: it's being determined either by wifi or cellular data location services or reflects your last known position = less accurate.

You should also be wary of INITIAL location fixes on ANY GPS device, assisted or not, until the ephemeris and almanac is fully downloaded.

Lance's screenshot appears to show his icon to be pulsing in which case Foreflight was relying on GPS information to determine his location. Put me in the camp of thinking that the georeferencing of the plate is inaccurate.
 
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alaskaflyer said:
I see no advantage to disabling your data signal to improve accuracy. There is no way that having a 3G signal could degrade anything other than your battery power and your sanity as chirping is heard in your intercom ;)
Click to expand...

Two things: On my IPhone (unlike the IPad), I cannot find a way to turn off the cellular radio other than airplane mode which also turns off the GPS.

I keep the 3g off on my IPad, because.... If my IPad loses GPS, it flags that location is lost. I do NOT want it using cell sites or wifi as means of finding location, because they may be inaccurate.

As far as Foreflight goes, I just completed an XC from Colorado to Florida and back, using FF for one leg, and FlightGuide IEFB for another. I am working on a pirep for that.
 
Pilawt said:
Settings / General / Network / "Enable 3G" and "Cellular Data"
Click to expand...

Yes, but the phone radio stays on (as does the cell site triangulation). On the IPad, turning off data turns off the cellular radio entirely.
 
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