EDV5002 heading deviation
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EDV5002 heading deviation
Do any CRJ pilots care to offer an educated guess as to what went wrong?
After deviating right of the instructed 105 heading, pilots kept focused on left turn, while they were already left of 105 heading. (big IF: if replay is accurately synced to audio)
In the clip from 60sec timestamp, DEPATURE talked about '105 heading you're gonna roll out on', EDV5002 replied '105 on a left hand turn' which implied a 270° left turn and was not corrected by ATC.
Seems the crew was running behind the events.
In the clip from 60sec timestamp, DEPATURE talked about '105 heading you're gonna roll out on', EDV5002 replied '105 on a left hand turn' which implied a 270° left turn and was not corrected by ATC.
Seems the crew was running behind the events.
Dunno what FMS they use (or if they were flying in a Nav mode at all) but on the model I operate with, if you type 105 it will fly heading 105, if you type L105 it will turn Left by 105 degrees. Maybe that happened and they were told 105 so again types L105. Would explain why they ended up facing the rough direction they did.
Dunno what FMS they use (or if they were flying in a Nav mode at all) but on the model I operate with, if you type 105 it will fly heading 105, if you type L105 it will turn Left by 105 degrees. Maybe that happened and they were told 105 so again types L105. Would explain why they ended up facing the rough direction they did.
Whether IRS or AHRS, the pilot and copilot heading would come from independent units, unless they had selected a reversionary mode.
The CRJ uses the Collins ProLine 4. The only heading control is via the heading select knob on the autopilot control panel. The displayed heading comes either from IRS or AHRS (depending on how the aircraft is equipped). If it has AHRS it could either be the original Collins AHC-85 (which is a piece of junk), or the newer Collins AHC-3000, which is very reliable.
Whether IRS or AHRS, the pilot and copilot heading would come from independent units, unless they had selected a reversionary mode.
Whether IRS or AHRS, the pilot and copilot heading would come from independent units, unless they had selected a reversionary mode.
Do any CRJ pilots care to offer an educated guess as to what went wrong?
https://www.youtube.com/watch?v=tW2UrzYSv5I
https://www.youtube.com/watch?v=tW2UrzYSv5I
Olden Daze before FMS … hidden autopilot trap ….you depart northbound 360 ….told to turn RIGHT to a heading of 270 Using the heading bug you turn it right and the machine starts to turn right as requested…you then quickly spin the heading bug to 270 as the aircraft goes through say 030 All is well….you think.
However Mr. Autopilot sees the heading bug on 270 and by defaults to the fastest way to get there so enthusiastically reverses the turn on you.
You quickly learn to turn the heading bug slowly until your desired heading is less than 180 from your passing heading in this case 090 or more.
Another interesting error was to select heading before centring the heading bug to your present heading.
Learning to use the FMS…both pilots in the sim staring at the FMS…”What is it doing now? More importantly, what the heck is it going to do next?!”
We quickly learned to say things like :”Ok when we get to the Blindman fix it is supposed to turn right to a heading of 175 if it doesn’t we’ll go from NAV to HDG mode, do the turn and figure out what we did wrong.”. Fun Daze. We kept the instructor highly amused for the first couple of trips.
However Mr. Autopilot sees the heading bug on 270 and by defaults to the fastest way to get there so enthusiastically reverses the turn on you.
You quickly learn to turn the heading bug slowly until your desired heading is less than 180 from your passing heading in this case 090 or more.
Another interesting error was to select heading before centring the heading bug to your present heading.
Learning to use the FMS…both pilots in the sim staring at the FMS…”What is it doing now? More importantly, what the heck is it going to do next?!”
We quickly learned to say things like :”Ok when we get to the Blindman fix it is supposed to turn right to a heading of 175 if it doesn’t we’ll go from NAV to HDG mode, do the turn and figure out what we did wrong.”. Fun Daze. We kept the instructor highly amused for the first couple of trips.
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A "professional" flight crew, with a fully functioning aircraft (as stated by said crew when inquired by ATC), can not fly an assigned heading after departure.... For over 4 minutes they are crisscrossing the sky turning around without getting anywhere near their assigned 105 hdg.
Am I the only one wondering what the h-ck this crew was doing? I hope there is more to this story or our sacred profession is in even more trouble than I thought...
Am I the only one wondering what the h-ck this crew was doing? I hope there is more to this story or our sacred profession is in even more trouble than I thought...
Let’s not over think this. The assigned departure was a simple 15 degree left turn. Both pilots had to have zero SA to screw that up! Even with a complete heading failure you could roll left for 5 seconds and level the wings and be good enough!
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It might be me; but I think I heard the FO readback 'H145' right at the start.
So: a moderate right turn, rather than a small left turn, and within the bounds of reasonableness. And ATC didn't correct the readback - there's a process failure, right there.
Easy to do: I've wound up, under reasonableness, 100* off heading in the days when headings weren't read back.
IMHO, the ensuing gyrations derive from the cockpit trying to work out what went wrong - and, likely, whose fault was it - rather than just accepting ATC's instructions at face value, and saving the post mortem for the cruise.
So: a simple mistake not caught, likely compounded by untimely management action.
Hindsight, and the advent of CRM, meant that, in my case, it was a oncer.
Short of pure incompetence, everyone gets a oncer: there's no need to shout incompetence as a first analysis.
So: a moderate right turn, rather than a small left turn, and within the bounds of reasonableness. And ATC didn't correct the readback - there's a process failure, right there.
Easy to do: I've wound up, under reasonableness, 100* off heading in the days when headings weren't read back.
IMHO, the ensuing gyrations derive from the cockpit trying to work out what went wrong - and, likely, whose fault was it - rather than just accepting ATC's instructions at face value, and saving the post mortem for the cruise.
So: a simple mistake not caught, likely compounded by untimely management action.
Hindsight, and the advent of CRM, meant that, in my case, it was a oncer.
Short of pure incompetence, everyone gets a oncer: there's no need to shout incompetence as a first analysis.
Last edited by Friendly Pelican; 25th May 2024 at 07:37.
Listen again. Almost as soon as they start turning right they are corrected and told very clearly to turn left to 105 and very clearly read it back. They are then told repeatedly to fly the 105 heading. How hard is it?
It appears that instead of putting hands and feet on the controls and turning the aircraft as instructed by ATC multiple times they may have been trying to program the FMS to do it for them. The CRM seems to have broken down. I can only imagine the cockpit conversation.
At 0.50 on the timeline, she reads back "left heading zero one zero five". On seeing the apparent wrong track being flown, I wonder why Radar didn't ask "what heading are you indicating?" This would have given an instant clue as to what was going wrong. Just to keep on repeating 105 wasn't going to solve the problem if they were having a malfunction or thought they'd already entered the correct heading. Years ago the next phrase would be "check your gyro against your magnetic compass, you appear to be tracking x degrees". I don't know if it's still taught these days.......
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Having listened to the video, the subtitles aren't accurate.
At 03m54s the pilot clearly says 'I think it's back to normal' so they - at that point - have understood that they were having issues of some kind.
The subtitles show '[Everything normal]' when the audio is very clearly 'I think it's back to normal' which is a bit odd.
That flight routes from Minneapolis to Montreal.
The FDR will probably reveal some kind of discrepancy. Does the FDR record from the magnetic compass as well as the inertial platform?
At 03m54s the pilot clearly says 'I think it's back to normal' so they - at that point - have understood that they were having issues of some kind.
The subtitles show '[Everything normal]' when the audio is very clearly 'I think it's back to normal' which is a bit odd.
That flight routes from Minneapolis to Montreal.
The FDR will probably reveal some kind of discrepancy. Does the FDR record from the magnetic compass as well as the inertial platform?
Last edited by Lascaille; 25th May 2024 at 21:40. Reason: adding
Having listened to the video, the subtitles aren't accurate.
At 03m54s the pilot clearly says 'I think it's back to normal' so they - at that point - have understood that they were having issues of some kind.
The subtitles show '[Everything normal]' when the audio is very clearly 'I think it's back to normal' which is a bit odd.
That flight routes from Minneapolis to Montreal.
The FDR will probably reveal some kind of discrepancy. Does the FDR record from the magnetic compass as well as the inertial platform?
At 03m54s the pilot clearly says 'I think it's back to normal' so they - at that point - have understood that they were having issues of some kind.
The subtitles show '[Everything normal]' when the audio is very clearly 'I think it's back to normal' which is a bit odd.
That flight routes from Minneapolis to Montreal.
The FDR will probably reveal some kind of discrepancy. Does the FDR record from the magnetic compass as well as the inertial platform?
No, the FDR does not record the standby magnetic compass. It does record the headings shown on the left and right primary flight displays.
A Proline 4-equipped CRJ will either have two IRS units or two AHRS units to provide heading and attitude reference.
IRS are independent of external references and should work properly if they were correctly aligned and placed in NAV mode before the aircraft moved from the gate.
I assume the IRS (if so equipped) would have been aligned before the aircraft left the gate. otherwise there would have been no attitude display on the left and right PFDs.
It would be entirely possible of course for IRS heading to fail at some later point after initial alignment.
AHRS on a CRJ could either be the original Collins AHC-85E, which has a slew of unreliability problems - (it is not a particularly robust design). Or, the AHRS could be the newer Collins AHC-3000, which is an excellent design and very reliable.
I don’t know if later model CRJs would have left the factory with AHC-3000s. I think most were delivered with AH-85Es. There is an STC to upgrade to the AHC-3000, but it is quite expensive to implement. I work on corporate CRJ-200s which all have the AHC-3000
Either AHRS model would receive magnetic heading from remote flux gate sensors which are located mid-span in the left and right wings.
With either IRS or AHRS, the pilot and copilot heading are normally completely independent, and come from the onside heading source.
If there is a heading disparity of 6 degrees or greater between the left and right sides, it will cause an amber EFIS COMP MON message to appear on the EICAS, (along with a master caution alert), and a red HDG flag will appear on both PFDs
In this scenario, the crew needs to determine which side (left or right) is correct by cross referencing the LH and RH PFD heading against the standby compass - and that is best done while in level flight, not while turning.
Once that is accomplished, they can use reversionary switches to force both PFDs to use the heading from only the left or right AHRS or IRS.
I suspect they did have a heading mis-compare, after takeoff, and took quite a bit of time trying to work out which side to use in reversionary mode. IF that was the case, they should have informed ATC immediately that they were having instrument issues instead of wandering all over the place leaving the controller to guess what they were up to.
If they had suffered a complete heading failure on both sides (unlikely but not impossible) I’m sure they would have returned to the departure airport - not continued on to Montreal.
If each side has both gyro and a flux gate, the gyro heading is going to be more accurate on a short term basis but the magnetic heading is the 'real' heading - does the system sort of blend one value into the other gradually (i.e. continually slew the gyro to match the flux gate when the platform is level?) And if the flux gate and gyro differ on a single side, I guess a failure is flagged up but what value is displayed?
Just intrigued to know what they might have been seeing here.
Again this departure was a 15 degree left turn. Any level of situational awareness should have been able to fly this departure regardless of cockpit indications. Dip the wings left, count to 5 and rollout. Once cleaned up tell ATC you have an issue. That heading by the way is the standard heading for all the eastbound flights off that runway. They should have done it many times.
Well, I looked back through flightaware - thankfully you can just change the date in the URL - and in the entire month of March I could only find one other example of that flight taking off to the southeast, and yes, as you've indicated the procedure is a left turn.
https://www.flightaware.com/live/fli...107Z/KMSP/CYUL
(you can just change 20240322 to 23, 24, etc and you'll see what I mean.)
So it's possible here that there had been a plan for and briefing for a northwesterly departure and a last minute runway change was the instigating factor. I'm not going to criticise airmanship though, because I wasn't there. And instrumentation factors - if existent - could have created a confusing situation.
Might be just one of those things where too many things happened at once. Brief one runway and one SID, get handed another last minute. Try to rebrief/reprogram before departure but don't want to slow things down for everybody else. Then encounter an instrumentation issue or glitch.
Not really fun when you've got some wag on youtube there to make a spectacle of it - especially with their misleading subtitles - so I try not to encourage sniping.
https://www.flightaware.com/live/fli...107Z/KMSP/CYUL
(you can just change 20240322 to 23, 24, etc and you'll see what I mean.)
So it's possible here that there had been a plan for and briefing for a northwesterly departure and a last minute runway change was the instigating factor. I'm not going to criticise airmanship though, because I wasn't there. And instrumentation factors - if existent - could have created a confusing situation.
Might be just one of those things where too many things happened at once. Brief one runway and one SID, get handed another last minute. Try to rebrief/reprogram before departure but don't want to slow things down for everybody else. Then encounter an instrumentation issue or glitch.
Not really fun when you've got some wag on youtube there to make a spectacle of it - especially with their misleading subtitles - so I try not to encourage sniping.
Last edited by Lascaille; 26th May 2024 at 01:21. Reason: adding