Partial panel
Joined: Sep 2006
Posts: 116
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From: Aylesbury,Bucks
As has been said, the panels are completely duplicated (backlight & inverters) etc. I am actually and electrical engineer and whilst it appears the design is very well duplicated one thing that often isnt is the software - i.e. a bug will appear in both screens - but is very unlikely. As it happens unlike the avidyne the G1000 will reboot in the "air". The avidyne must be on the ground!
I have actually tested this in flight (dont ask..)
I have also suffered an AHRS failure - very worrying! But in reality with all the rest of the nav stuff it not that difficult. From years of steering boats with mag compasses in very bad weather a plane was easy - BUT without a GPS or VOR etc. I would feel very uncomfortable and certainly get radar or DND assist.
I did hear of a fellow where the fans died (and he didnt notice) and the panels overheated - so it is possible - but very difficult.
I had a similar conversation with my wife years ago (about boats) - and after an repeated number of "what if's" I came to the conclusion that eventually you are f....ked - so enjoy your life while you can! You can only protect against a given number of simultaneous failures, and then you have to wing it...
What I am certain of is that compared to the convetional (non-duplicated) instrument panel I would go for the glass every time!
I have actually tested this in flight (dont ask..)
I have also suffered an AHRS failure - very worrying! But in reality with all the rest of the nav stuff it not that difficult. From years of steering boats with mag compasses in very bad weather a plane was easy - BUT without a GPS or VOR etc. I would feel very uncomfortable and certainly get radar or DND assist.
I did hear of a fellow where the fans died (and he didnt notice) and the panels overheated - so it is possible - but very difficult.
I had a similar conversation with my wife years ago (about boats) - and after an repeated number of "what if's" I came to the conclusion that eventually you are f....ked - so enjoy your life while you can! You can only protect against a given number of simultaneous failures, and then you have to wing it...
What I am certain of is that compared to the convetional (non-duplicated) instrument panel I would go for the glass every time!
Joined: May 2001
Posts: 10,804
Likes: 1
Just to note.
I would completly ignore all instructions from the CAA and turn my mobile phone on in the case of radio failure. And phone my home tower. They can then contact DnD and get them to ring you back.
BTW this occurance of all your primary glass data going up the swanny is a relatively common occurance in some larger aircraft if you are flying near rain clouds. The static can get to them and then the whole lot throws a fit (three times in 800 hours which is high for any fault in my limited experence). Auto pilot kicks out captain starts swearing because he has to fly it on backup instruments. Once your away from the source of the static it reboots and everything comes back online. First time it happens its a bit of a shock and sods law makes it happen just as you get put on vectors by the director in IMC. And the whole data bus goes, so no AHRS, no air data computer, no stall protection, and 4 screens which flash on and off and look remarkably similar to the test mode with all the warnings up. It takes about 3-5 mins for everthing to get its life sorted.
Our backup instruments are a bat backed up AH with ILS guidance and a pressure driven ASI and Altimeter. Just have to hope your with a radar service and get timed turns for the heading or run a GPS track.
I would completly ignore all instructions from the CAA and turn my mobile phone on in the case of radio failure. And phone my home tower. They can then contact DnD and get them to ring you back.
BTW this occurance of all your primary glass data going up the swanny is a relatively common occurance in some larger aircraft if you are flying near rain clouds. The static can get to them and then the whole lot throws a fit (three times in 800 hours which is high for any fault in my limited experence). Auto pilot kicks out captain starts swearing because he has to fly it on backup instruments. Once your away from the source of the static it reboots and everything comes back online. First time it happens its a bit of a shock and sods law makes it happen just as you get put on vectors by the director in IMC. And the whole data bus goes, so no AHRS, no air data computer, no stall protection, and 4 screens which flash on and off and look remarkably similar to the test mode with all the warnings up. It takes about 3-5 mins for everthing to get its life sorted.
Our backup instruments are a bat backed up AH with ILS guidance and a pressure driven ASI and Altimeter. Just have to hope your with a radar service and get timed turns for the heading or run a GPS track.
Joined: Sep 2002
Posts: 778
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From: London, UK
Some of these scenarios are definitely one advantage of some of the other glass panel systems (e.g. the Avidyne or Chelton) over the G1000, i.e. you lose your glass panel but you keep your Garmin 430/530/whatevers.
Joined: Sep 2006
Posts: 116
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From: Aylesbury,Bucks
mad_jock - interesting situation - although I had not thought of it - the mobile phone is an excellent idea.
I suspect the multiple screen failure is to do with ESD immunity - older devices were often crap. It has improved massively on modern stuff ( by design,statute requirements and testing), but as all this kit gets more sophisticted then it could still be possible (but they are required to recover). G1000 recovery time from re-start is about 20 seconds basic and 60 seconds AHRS.
Not sure I see the difference between two G1000's (which infact they are) and an Avidyne with a Garmin if you are suffering from such catastrophic failure? Given that the Avidyne cannot re-boot in the air I would be extemely worried about being near electrical storms.
Just because it is sold as a "system" - just remember each panel is an complete system (e.g. a 430/480/530). That is appart from power etc.etc.
ALSO I want lower power when on stby battery - so too many seperate instruments on backup power = less time to survive.
I suspect the multiple screen failure is to do with ESD immunity - older devices were often crap. It has improved massively on modern stuff ( by design,statute requirements and testing), but as all this kit gets more sophisticted then it could still be possible (but they are required to recover). G1000 recovery time from re-start is about 20 seconds basic and 60 seconds AHRS.
Not sure I see the difference between two G1000's (which infact they are) and an Avidyne with a Garmin if you are suffering from such catastrophic failure? Given that the Avidyne cannot re-boot in the air I would be extemely worried about being near electrical storms.
Just because it is sold as a "system" - just remember each panel is an complete system (e.g. a 430/480/530). That is appart from power etc.etc.
ALSO I want lower power when on stby battery - so too many seperate instruments on backup power = less time to survive.
Thread Starter
Joined: May 2001
Posts: 4,631
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From: UK
I have actually tested this in flight (dont ask..)
Oh please, do tell. Anything you say wont go any further, and wont be used in evidence against you.
As it happens unlike the avidyne the G1000 will reboot in the "air".
So how does it sort out the attitude?
OK so as unlikely as this type of failure, any more comments about what you would actually do please.
Oh please, do tell. Anything you say wont go any further, and wont be used in evidence against you.
As it happens unlike the avidyne the G1000 will reboot in the "air".
So how does it sort out the attitude?
OK so as unlikely as this type of failure, any more comments about what you would actually do please.
Joined: Sep 2006
Posts: 116
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From: Aylesbury,Bucks
Small Tip: When upgrading the databases - check the cycle number of each panel BEFORE takeoff, just in case it didnt happen first time 
I needed to update the GPS database in flight - cos if they dont match between the panels - they dont want to talk to each other. Since I was near the airfield I took the descision to "upgrade" in the air. (Knowing i could get down quickly if it went wrong
). Powering off the PFD is harder than you think (see previous posts).
The AHRS requires you to fly straight and level - ish (using the AI) and will then recover - i am not sure of the exact algorithm but I think they use more that just the gyros - the magnetic system plays a part. I must admit I have not tried to confuse it by resetting at an adverse attitude. It knows if you are off balance on the gound so I assume it will do the same in the air.
I am now going to hide.
I needed to update the GPS database in flight - cos if they dont match between the panels - they dont want to talk to each other. Since I was near the airfield I took the descision to "upgrade" in the air. (Knowing i could get down quickly if it went wrong
). Powering off the PFD is harder than you think (see previous posts).The AHRS requires you to fly straight and level - ish (using the AI) and will then recover - i am not sure of the exact algorithm but I think they use more that just the gyros - the magnetic system plays a part. I must admit I have not tried to confuse it by resetting at an adverse attitude. It knows if you are off balance on the gound so I assume it will do the same in the air.
I am now going to hide.
Joined: Feb 2003
Posts: 2,042
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From: Oxford
I would completly ignore all instructions from the CAA and turn my mobile phone on in the case of radio failure. And phone my home tower. They can then contact DnD and get them to ring you back.
Tim
Joined: May 2001
Posts: 4,729
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From: 75N 16E
I suspect the reality would be you would also be without the "on board" radios becasue even if these continued to operate you would have no way of knowing what frequency was selected (although I suppose you could stay on the last selected, or if really clever might work out how many turns did what!!! ).
You can try these AHARS or ADC failures in the air by pulling the relevant circuit breakers........
I think that although you can get hung up on scenarios like this, it is far more likely that you will be flying in a conventional aeroplane and loose all nav than one of these types (I know people it has happened to in IMC). It is also worth bearing in mind that the benefits probably outweigh any perceived risks. With the very accurate map, if you lost your engine at night over hostile terrain or in IMC, you *may* be able to navigate to a road or other suitable area and land on that. I simulated EF in IMC over LA in the sim (FAA approved with surround external visuals). Found a road and broke out of the cloud at 500' lined up and landed. Ok it was a sim, but get my point?
Joined: Jun 2003
Posts: 13,787
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From: EuroGA.org
The other thing is that the southern UK is one of the few places where one can get a GSM phone connection while being above the MSA.
Doesn't the DA42 have a conventional altimeter, plus a backup battery which drives an electric horizon?
No matter what, there will always (in GA a/c) be single points of failure, which is why carrying a GPS and a radio is the way to approach this. It's not an expensive solution.
Doesn't the DA42 have a conventional altimeter, plus a backup battery which drives an electric horizon?
No matter what, there will always (in GA a/c) be single points of failure, which is why carrying a GPS and a radio is the way to approach this. It's not an expensive solution.
Joined: Feb 2005
Posts: 551
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From: England
Joined: May 2001
Posts: 10,804
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What sort of instructions do you get in regard to handeling the AHRS?
We had to watch a video on transporting the things. Basically it appeared that if an engineer farted within 2m of the transport box it would knackar them. If removed from the box it was up to 50m.
Do you get any guidance about moving the aircraft without spinning them up first?
We had to watch a video on transporting the things. Basically it appeared that if an engineer farted within 2m of the transport box it would knackar them. If removed from the box it was up to 50m.
Do you get any guidance about moving the aircraft without spinning them up first?
