[Username Protected]

Hi everyone,

I was on a flight from Dubai (OMSJ) to Adana Turkey (LTAF). When we hit northern Iraq we got intermittent jamming. The jamming continued and got worse until we completely lost GPS in southern Turkey. If you want to look in flight aware N69FX on September 13th and 14th.

I'm sure this is obvious to most of you but the G3000 does not have the ability to update it's position from VORs. So, when GPS is lost the moving maps stop working.

What's not so obvious is what you lose when you lose GPS. If you need to pull Iridium weather you can't. "Next 500 miles of flight plan" doesn't work because there is no position. You can only get waypoint weather.

I've had jamming on previous flights but this flight something different happened. After the jamming stopped, the plane didn't re-acquire GPS until a ground restart. 2 ipads, an iphone, and an android all recovered GPS. Not the G3000. Flying from LTAF back to OMSJ were were jammed 5 minutes after takeoff and then had no GPS all the way back to OMSJ.

So, a question for the group. When the GIA gets jammed then AHARS 1 and 2 stop working. The PFD get's it's attitude feed from the standby instrument. (Hmmm... perhaps not altitude though because I noted a difference between the standby's altitude and the PFD altitude). I didn't want to start popping circuit breakers at FL450. Any thoughts on what circuit breaker could be pulled to reset the GPS and what else would get taken down?

Another thought, this would be a fantastic sim training scenario for pilots (like me) that learned to fly in planes with GPS.

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[Username Protected]

Anyone who hasn't seen how the plane behaves with a dual GPS failure should do it in your next training. It's eye opening how much you lose that gets taken for granted if you are just thinking you need to navigate via VORs.

Regarding the AHRS, note that GPS loss doesn't stop them from working - they just run degraded. See FOL PHE505-006/16:

When GPS signal is not available, the AHRS 1 FAULT and AHRS 2FAULT CAS messages will be displayed simultaneously, indicatingthat both AHRS are operating in a degraded mode. This is differentthan an AHRS FAILURE, where the AHRS system becomesinoperative.

The GPS are integrated into the GIA, so you'd need to reset one of the GIA circuit breakers. Obviously there is a LOT of functionality in the GIA, so losing one if it doesn't reset properly could certainly put you in a worse condition - no AP, loss of FD redundancy, loss of half your VOR/ILS.
I haven't done a simulated single GIA failure but it would be interesting to see how it behaves.

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Regarding the AHRS, note that GPS loss doesn't stop them from working - they just run degraded. See FOL PHE505-006/16...

I stand correct. I was incorrectly reading FOL PHE505-004/19 which states "In case both AHRS 1 FAIL and AHRS 2 FAIL CAS messages aretriggered simultaneously, the Standby Attitude Indicator (STBY ATT) data will be automatically presented in PFDs, and pilots shall use the
COMPASS as heading reference."

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Yea, the Garmin/Embraer FAULT vs FAIL terminology isn't great. Most people read FAULT as FAIL. I wish they'd just use <SYSTEM> DEGRADED if that's what they mean.

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(Username Protected)-

Bummer, sounds like a flying sim session! A few notes:

1) The G3000 actually does support DME/ DME position updating when GPS info is lost. However, (big however) I don't think Embraer opted to configure this capability. I know for a fact Textron did for the M2/ 3+. Maybe if enough owners ask this can be enabled for the Phenoms.

2) It's interesting and unexpected that the aircraft didn't re-acquire GPS position when consumer electronic devices did. Did you ask Embraer about this? I'd love to know what you find out. You can look at the GPS status from the touch controller- Utilities- FMS Sensors off the top of my head, but might be remembering incorrectly where it is exactly. This will pull up a pane on the MFD showing satellites seen, strength, position error, etc. Snap a photo if you experience this again.

3) Losing GPS in and of itself doesn't automatically mean the AHRS is lost. AHRS should still work as long as it is receiving valid air data. However, in the past, there have been problems when Phenoms lost GPS and were flying at high speed. The difference between left and right air data inputs combined with the loss of GPS did fail AHRS. This was supposed to have been fixed long ago via software update, but sounds like maybe not? There was a recommendation from Embraer to limit maximum Mach if GPS was lost...

4) GPS is integral to the GIA, so I don't think you could reset a GPS without depowering the entire associated GIA. Then you'd lose COMM/ NAV/ Flight Director, and possibly the associated PFD. Not sure what unit computed the "symbol generation" for the PFDs- the GIA or the GDU itself. I would really not want to pull a GIA CB inflight...

3)

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Here's a video I shot with the Citation Jet Pilots Safety and Education Foundation in a CJ3+ sim (G3000); the first couple minutes discuss loss of GPS:

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1) The G3000 actually does support DME/ DME position updating when GPS info is lost. However, (big however) I don't think Embraer opted to configure this capability. I know for a fact Textron did for the M2/ 3+. Maybe if enough owners ask this can be enabled for the Phenoms.

Based on my interaction with contact center the only way this will get fixed is we get the product manager to do a flight in IMC through southern Turkey.

2) It's interesting and unexpected that the aircraft didn't re-acquire GPS position when consumer electronic devices did. Did you ask Embraer about this? I'd love to know what you find out. You can look at the GPS status from the touch controller- Utilities- FMS Sensors off the top of my head, but might be remembering incorrectly where it is exactly. This will pull up a pane on the MFD showing satellites seen, strength, position error, etc. Snap a photo if you experience this again.

Contact center's response has been less than inspiring. Basically - system was jammed, we can't improve it, learn for fly the plane without GPS. (... and weather data, and SIDS and STARS, and point to point navigation). Well, no, their first response was that they didn't believe GPS didn't recover. I had the GPS sensor page up. During the jamming event zero satellite reception. After moving out of the jamming area GPS had full reception from up to 6 satellites and no GPS acquisition. Even on the ground after landing. As soon as you ground reset it acquires GPS lock.

3) Losing GPS in and of itself doesn't automatically mean the AHRS is lost. AHRS should still work as long as it is receiving valid air data. However, in the past, there have been problems when Phenoms lost GPS and were flying at high speed. The difference between left and right air data inputs combined with the loss of GPS did fail AHRS. This was supposed to have been fixed long ago via software update, but sounds like maybe not? There was a recommendation from Embraer to limit maximum Mach if GPS was lost...

AHARS FAULT was the message, not fail. As you know I have load 22. There were no problems with the AHRS1 and AHRS 2 miscompare error even at Mach .74 for 1 hour. (240 KIAS/0.63 Mach is the restriction)

4) GPS is integral to the GIA, so I don't think you could reset a GPS without depowering the entire associated GIA. Then you'd lose COMM/ NAV/ Flight Director, and possibly the associated PFD. Not sure what unit computed the "symbol generation" for the PFDs- the GIA or the GDU itself. I would really not want to pull a GIA CB inflight...

If pulling a circuit breaker means temporary loss of autopilot, yaw damper, altitude, attitude and a VORs that would be ok. You could slow down and hand fly off the standby instrument during the reset. If I was flying into IMC in a mountainous region with no radar below a certain altitude.... I would be pulling circuit breakers all day long before descending. But, it would be nice to know what's going to happen ahead of time. Contact Center has been reluctant to suggest any sort of reset procedure.

We actually did almost get into Iranian airspace. We were being vectored and using our Ipads as backups. Got vectored towards Iranian airspace and we just turned ourselves before entering. If we didn't have the Ipads, or if Iranian airspace was a mountain, bad stuff would happen.

Here is a picture on the ground at OMSJ after our return from LTAF. There was definitely no GPS jamming going on at OMSJ. No GPS position.

Oh, yes, ADS-B out dies so space based ADS-B when it becomes more common won't work either. For the entire flight. That would be problematic for the North Atlantic.

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Oh, one thought I had AFTER we landed. If you are completely jammed but have VOR/VOR reception you can plot your course on Foreflight using the VOR/RADIAL/DME and VOR/RADIAL/VOR/RADIAL waypoint entry. I did figure out inflight that the ForeFlight ruler (press with two fingers and move to adjust ruler ends) allows you to quickly determine magnetic heading and distance.

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I have had such failures over Salt Lake City. Suddenly you find yourself with numerous failures and they are all related. You might be the only one reporting them to ATC. Your course and distance information disappear and there might be several different fail or fault indications. But the problems all start at approximately the same time as the jammers are deployed and they end 40 or 50 miles later. I agree that pulling CB’s for this is not a good idea unless you have a checklist for it and you are really sure what is happening. Especially if you are in IMC conditions. The systems are so integrated that one failure can appear as many failures. Mag compass is a good idea and so is comparison of all remaining data from #1,#2 and STBY.

I think we should all be very aware of GPS jamming and other such things we may not even know about as the world goes to war.

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Thank you (Username Protected) for the Ready for Recurrent video. Well done.
and thank you to CJP for making the safety videos available to everyone.