Mini iPad Latency

[Bartman]

Hi all,

Was wondering, with an iPad Mini is the artificial horizon display in real time or is there latency that would make it dangerous as a primary attitude reference in an emergency?

Is Foreflight related to the artificial horizon or is that something different? I really don't know much about the iPad Mini other than it's out there and people are using it with ForeFlight.

Thanks,
Bart

 

[Big Ed]

I tested Garmin Pilot with a GDL-50 displaying AHRS on an iPad Mini and Android phone and tablet.

The latency in Synthetic Vision view is very bad. Probably a full second between movement of the device and display. I would not fly on it.

However, in Nav data view with the AI ball and DG displayed, there is no latency that I could detect.

I would not trust the internal display sensors alone. AFAIK the AHRS sensors in an ADS-B In device such as a GDL-50 are the same sensors used in IFR-legal devices such as the G5. However, there are too many failure modes in such a setup for my comfort. You have to worry about either the ADS-B receiver or the display device running out of battery or overheating, or the Bluetooth connection failing.

Having said all that, I just spent a week scud running about 1500 miles in terrible weather in FL, GA, SC, and NC. Was running under a low ceiling and dodging rain cells the whole way. Real time weather radar imagery in the cockpit is a game changer. If you don't have an ADS-B receiver and display running a moving map, you are missing out on the single most consequential safety development for pilots since the invention of the Attitude Indicator.

 

[Bartman]

no doubt Ed but I don't have it.

you were scud running with the iPad displaying attitude info just in case?

 

[BB57]

I use a 9.7" iPad with Flight Plan Go taking input from a Stratux.

The lag in the AH is pretty significant - on the order of a second or so. I would not want to fly an approach with it as a primary instrument. But if I didn't have to deal with significant turbulence, it would probably work in an emergency.

Since I don't have an AH in the panel I have used it mostly identify 15 degree, 30 degree, 45 degree, 50-55 degree and 60 degree bank angles (all key angles in some required maneuvers) more precisely and associate those angles with the appropriate visual references, but again it requires holding a bank angle for a second or so to get an accurate indication.

There's a similar delay in the AHRS compass, but again under stable conditions it can be useful. I've used it to swing a compass on the ramp. It's a straight forward process.

----

I'll echo what Big Ed said about the ADS-B weather "in" capability. Eastern NC in the summer can be a challenge. A typical pattern is clear weather in the early morning but with surface temp being right at the dew point, which turns into a overcast to broken ceiling at 300' to 1500' by 9-10am when that moist air starts to lift. The height and extent of the ceiling can vary a lot in just 10-20 miles. It eventually burns off to a scattered ceiling that starts to rise, giving you decent flying until 2-4pm when thunderstorms start popping up all over.

Being able to get current weather can be helpful in the late afternoons when dodging those storms. In the past, you'd be able to see out the window to doge what was there but you often could not see what was behind a storm or line of storms. With ADS-B "in" weather and the radar mosaic you can get a much fuller picture of what's beyond your visual range, the overall picture and the directio things are moving.

The caveat with the radar mosaic is that it is assembled from various ground radars and that process can take anywhere from 7 to 20 minutes, and then it takes another minute or two to upload to the system and show up on your iPad or other display. That means the display shows where the precipitation was 8 to 22 minutes ago. You'll notice what you see out the window won't align perfectly with what's on the display. That works ok as long as you can see out the window and in IFR or at night, you need to be sure to keep well out in front of / away from what is showing on the display with that latency in mind.

The radar is also just showing precipitation so a thunderstorm that is still in the all updraft, developing stage won't have any precipitation to produce a radar return.

Still it is exponentially better than what we had way back in the day with nothing except looking out the window and radioing FSS to see if they could give you an idea of the larger picture along the route.

 

[BB57]

no doubt Ed but I don't have it.

you were scud running with the iPad displaying attitude info just in case?

I'm pretty sure Ed was referring the ability to get current weather updates as well as *reasonably* real time radar mosaic and satellite imagery overlaid on the sectional map display with ADS-B"in" weather.

You can get a Stratux for around $240. Mine is suctioned cup in the rear corner of the skylight, with an external GPS antenna on the cross tube under the skylight.

 

[Bob Turner]

I don't depend on this stuff, but 100% agree that satellite weather is a game changer. Radar is attenuated, and you cannot see what you are getting in to, but satellite weather allows you to see whether it is clear on the back side.

Airbus weather radar was a Godsend, but could not compare to this new presentation.

 

[Big Ed]

you were scud running with the iPad displaying attitude info just in case?

No, I was scud running with the IPad Mini displaying moving map with weather and traffic feeds from ADS-B in via GDL-50.

Eastern NC in the summer can be a challenge.

Was certainly a challenge last week. I flew from Tampa to Jacksonville, NC on Tuesday morning, then flew to Atlanta with stop at Fayetteville on Thursday, and return home on Saturday. Whole week was a hash of occluded fronts all over the SE. Plus a line of storms formed every day in the Gulf and drifted across from Tallahassee to Jacksonville FL. Coming home, had to weave thru a gap between systems along the GA/FL line. Might have been stressful without ADS-B In. Was a non-event with it.

I hate smug pilots, but that's one of those "is your life worth 500 bucks" things.

 

[Big Ed]

LOL, dug up historical radar data from my flight home on Sunday. See below. Red line is my approximate flight path.

Could I have talked to Jax FSS and done the same thing with vectors? Nope, because my radio quit receiving somewhere between Atlanta and Macon. But thanks to ADS-B, I got home safe and happy after a relatively non-stressful flight.

 

[aftCG]

I tested Garmin Pilot with a GDL-50 displaying AHRS on an iPad Mini and Android phone and tablet.

The latency in Synthetic Vision view is very bad. Probably a full second between movement of the device and display. I would not fly on it.

However, in Nav data view with the AI ball and DG displayed, there is no latency that I could detect.

I would not trust the internal display sensors alone. AFAIK the AHRS sensors in an ADS-B In device such as a GDL-50 are the same sensors used in IFR-legal devices such as the G5. However, there are too many failure modes in such a setup for my comfort. You have to worry about either the ADS-B receiver or the display device running out of battery or overheating, or the Bluetooth connection failing.

Having said all that, I just spent a week scud running about 1500 miles in terrible weather in FL, GA, SC, and NC. Was running under a low ceiling and dodging rain cells the whole way. Real time weather radar imagery in the cockpit is a game changer. If you don't have an ADS-B receiver and display running a moving map, you are missing out on the single most consequential safety development for pilots since the invention of the Attitude Indicator.

Hi all,

Was wondering, with an iPad Mini is the artificial horizon display in real time or is there latency that would make it dangerous as a primary attitude reference in an emergency?

Is Foreflight related to the artificial horizon or is that something different? I really don't know much about the iPad Mini other than it's out there and people are using it with ForeFlight.

Thanks,
Bart

The AHARS from my Stratus transponder drives my iFly 740, and I have the Dynon D3 which has its own internal AHARS data. Both appear fluid in normal flight conditions, which could lead one to believe you could trust them if you lost the horizon for any of a number of reasons.
Having done quite a bit of manuevering and riding out mountain turbulence there is no way I would trust either in actual IMC.

 

[Bartman]

Back to this topic, I spoke with a factory tech guy from Garmin, he seemed to think the AHRS data from a GTX 345 would drive the Garmin Pilot attitude display in real time but suggested I get confirmation from an engineer. Will circle back around to this when some other smallish problems are figured out so nothing final yet.

 

[rmac]

I’ve started experimenting with this in my Bonanza since I’m partway through system upgrades and no longer have backup vacuum. I’d like some kind of backup and still hope the GTX345 can successfully drive my iPhone or iPad. So far, it hasn’t worked at all. Straight and level it was jumpy but sort of okay. However, a level, standard rate right turn through 90 degrees of heading change led to a 25 degree nose up indication on the iDevices. Same thing to the left gave 25 degrees nose down. It was the same on both Foreflight and Garmin Pilot.
I’m working with Garmin on this in case the 345 attitude info is bad, but my troubleshooting is on hold until my plane is out of annual.

Rick

 

[Bartman]

I’ve started experimenting with this in my Bonanza since I’m partway through system upgrades and no longer have backup vacuum. I’d like some kind of backup and still hope the GTX345 can successfully drive my iPhone or iPad. So far, it hasn’t worked at all. Straight and level it was jumpy but sort of okay. However, a level, standard rate right turn through 90 degrees of heading change led to a 25 degree nose up indication on the iDevices. Same thing to the left gave 25 degrees nose down. It was the same on both Foreflight and Garmin Pilot.
I’m working with Garmin on this in case the 345 attitude info is bad, but my troubleshooting is on hold until my plane is out of annual.

Rick

Yowsa! That's some pretty severe deviation from what you'd expect to see! Please keep us posted as you work through it and thanks for chiming in.
Bart