Departure with non-functional "glass" legal?

[IO540]

Presumably, a VFR departure is legal because there are sufficient backup instruments to meet the type certificate requirements for day VFR.

But is that always the case? What if the LCD which has packed up is the one carrying the primary engine instruments? If your "required" oil pressure gauge has gone, you are stuffed.

However, I can't see IFR being legal unless one also has a separate GPS (normally the case with a G500/600) and a CDI mounted within the pilot's immediate field of view.

[Fuji Abound]

However, I can't see IFR being legal unless one also has a separate GPS (normally the case with a G500/600) and a CDI mounted within the pilot's immediate field of view.


Which would very much depend on the glass in question. Avidyne have gone down the route of driving the primary displays from 430s. The 430s should of course continue to function in the absence of the MFD, albeit clearly with some electrical failures it would be conceivable to lose the lot.

Garmin on the other hand have effectively incorporated a pair of 430s in the avionics bay out of sight and out of mind. The units are driven exclusively from the twin glass screens. Should the glass fail or some vital component of the glass you would be left with no navigational functions what so ever (other than the trusty GPS in your flight bag). In theory with dual screen redundancy in Garmin's case both screens would have to fail. In Avidynes case there isnt dual redundancy unless R9 is in use.

As you know in all cases a dial AI is a certification requirment. In some aircraft some thought appears to have been given to the placement of the dial, while in others you cant help feeling it is more an after thought. Again in some circumstances it is conceivable you could lose the AI as well, but very unlikely unless you have delayed getting back on the ground for far to long.

Glass redundancy also means than there will be a dial engine RPM and altimeter but that is it. There are some installations which include dial engine instruments - for example on some Cirrus you will see the conventional engine dials.

You would be mad to go, knowingly entering IMC with a failed panel or very desperate and not worried about the CAA.

That said in some aircraft with glass you would have a compass, an AI, an altimeter, engine RPM, perhaps some other engine instruments, radios including navigational and a functioning auto pilot (which if often coupled to varying degrees to the 430s). Some would say you are in heaven me boy, all I needed was a compass an AI and an altimeter, what are you complaining about!

[IO540]

The reason I ask the Q is that I see a very consistent pattern on my long trips to the "south": very few glass cockpit planes.

I see mostly Cessnas, Mooneys, all the old iron with steam gauge panels.

But I can barely remember seeing a single modern SR22 down there - not one which actually flew any distance. Yet, about 200 of them have been sold in Europe and, due to the capability, you would expect to see them doing a lot of serious flying. A 100 or so (according to COPA) have been sold to Germans who are a lot closer to the south than we are.

I had a raft of avionics issues on my TB20 when it was new. I strongly suspect that Socata, having already by then decided internally to stop production, built mine out of a pile of avionics which were returned by customers with intermittent faults, and "certified OK" by the usual bench test ape. The in-warranty bill was some £50k-£100k as a result (expressed in retail list prices which of course nobody in the business actually pays). It costs me a lot of hassle but above all it stopped me from doing any long trips for a whole year.

I am wondering if a glass cockpit owner who gets a few gremlins thinks twice about going anywhere for real... I certainly would. You cannot easily find a Garmin/Avidyne dealer in Spain, Corsica, Sardinia, Italy, Croatia, Greece. And getting one down to the plane, with you being there for just a short break of say 1 week, is going to be a huge hassle.

Basically, the touring community seems to be shunning glass cockpits.

[1800ed]

At least with an R9 or G1000 setup you can change the screen functionality, so if you had a single display failure you could use the remaining working one. On the old Avadyne setup it would be annoying to have a nice big screen just telling you EGT and CHT info and having to use your backup steam dials.

[dont overfil]

For VFR shirley the second screen is the first line of redundancy. Engine instruments, alt, VSI and horizon can be moved to the second screen.

The analogue instruments are the next line of redundancy but (on C182) there are no engine instruments whatsoever. Adjust for maximum noise?:ok:

D.O.

[Rod1]

That is also a question I asked. My aircraft has redundancy in everything except the t’s and p’s, but it does have a master warning system (big red light) which comes on if these go out of limits. In reality, this is ok if you get a failure in flight but I would not take off with such a problem. Fortunately, I could get a replacement unit shipped anywhere in Europe quite fast and provided I could borrow a few tools I could have it swapped out in under a days work. So far the system has performed well.

Rod1

[Fuji Abound]

IO540

There are two Cirrus at Split and a DA42 for example so they are down south.

I know of pilots in the UK who often fly Cirrus (and DA42s) to the south including someone who does regular trips to Cyprus and others who have been to North Africa.

I hear of very few failures, although of course they happen. It also seems to me occasionally there can be gremlins with new aircraft but they work themselves out.

However I am not sure there is any evidence of glass aircraft being often grounded in far flung parts of the world waiting for parts and qualified personel; but yes, it must happen on occasions.

I have only been stranded in a brand new aircraft which was known to have problems. While I dont have time to often go to the deep south I dont think the aircraft knows where it is so the failure rate is what it is.

I would agree that repairs could be a issue when they happen, although I suppose the cost of putting a qualified enginer on a Sleezy Jet to the nearest Sleezy Port would not be the end of the world. Parts are pretty easy to change in the field, particularly Avidyne where I gather they tend to simply swap screens with a serviceable screen.

[IO540]

On a CofA plane, the legality will simply be according to the instruments listed as required for day VFR in the POH. I am sure all glass equipped planes will have such a listing.

But there is unlikely to be many (or any) which can fly IFR with the LCDs gone.

On a non-CofA plane I have no idea what determines the legality or whether this matters at all, but they will all be VFR-only anyway and you can do all that with a handheld GPS, so long as you have the speedo, the altimeter and engine gauges.

Fuji, you are of course right in that flying somebody out there is possible but it's probably going to take weeks or months, especially if you don't have a long term fulfilling and total-fidelity relationship with an avionics dealer ;)

This is why I am sticking with individual instruments. Some of the stuff (http://www.sandel.com/SN3500.php) out there is pretty nice if not exactly cheap, and can still be field-swapped. I guess the simple retrofits like the Aspen (http://aspenavionics.com/index.php/products/) can be field-swapped but the setting up would be beyond non-specialised avionics people. The Garmin (https://buy.garmin.com/shop/shop.do?pID=63598&ra=true) glass cannot be field swapped without a Garmin specialist for that specific product because one has to load some data which only an authorised dealer has access to. I wonder what their autopilot is like. In contrast, the Honeywell autopilot servos are dead easy to field swap (just as well) and the computer is doable too with a laptop connection.

[Fuji Abound]

IO540

I am not sure I would be quite so nervous about getting an engineer on site. Most owners are going to use one of a few shops for these type of aircraft and often these are not at the owners base. Problems can occur at the owners base or away from base. I have to say that one particular shop I can think of dont seem to have a problem looking after their owners. If you need an engineer on site because the aircraft cant be flown they will get someone there the next day or at least within a day or two. Great service, obvioulsy at a cost. While I have no personal experience I suspect they might even prefer a trip abroad rather than a four hour or more drive.

I am not suggesting you want it to happen but then again I wouldnt expect these units to fail very often.

[wigglyamp]

The G500 PFD does not require specifc software loading if it's replaced, although the peripheral sensors (ADC, AHRS or magentometer) may require a software level change if replaced - it will depend if the version they ship with from Garmin as a spare is at the same system level as the G500 installation approval. The remote sensors are the same units as those in the G1000 but can have different unit-specific software in different patforms.
So far, with 9 G500/600s completed in 20 months, we've had NO failures.

In terms of going flying with a duff EFIS, the AFMS does limit depature to VFR only if the G500 is defective. In a G500, you don't necessarily have to have a back-up CDI (it will depend on the specific STC but ours allow this), provided that another useable source of Nav display is available - the map on the GNS530W or 430W is acceptable.

[dublinpilot]

On a CofA plane, the legality will simply be according to the instruments listed as required for day VFR in the POH. I am sure all glass equipped planes will have such a listing.

But there is unlikely to be many (or any) which can fly IFR with the LCDs gone.

On a non-CofA plane I have no idea what determines the legality or whether this matters at all, but they will all be VFR-only anyway and you can do all that with a handheld GPS, so long as you have the speedo, the altimeter and engine gauges.


I know it might be a bit more awkard for your IFR boys :O but couldn't you always just fly back under VFR? It might take a day or two longer to get the weather right along the route, and you might have to do a bit more planning, but at least you could safely and legally fly home.

You wouldn't be grounded as such; just not able to fly IFR. :confused:

[Fuji Abound]

You wouldn't be grounded as such; just not able to fly IFR.


The lack of any engine instruments is probably the gotcha.

Whether you are happy or not knowing nothing more than the rpm the engine is producing is going to be down to personal comfort, but some will want to keep an eye on TandPs for a longish ferry flight.

Mind you for a not a lot I guess a couple of dial gauges could be added to the panel of most aircraft if you wanted that extra permanent redundancy.

[IO540]

couldn't you always just fly back under VFR?

Yes, you would fly back under VFR if the POH allows it (which might mean going shopping for a load of VFR charts, etc and waiting for good weather :) ) but a different gotcha is that any flight may not be possible if you have lost "required" engine instruments.

However there appears to be considerable variation.

Here (http://www.uofmflyers.org/pdfs/172SIMAUS-03.pdf) is a C172 POH. If you go to pages 2-14/2-15, you'll see that either the PFD or the MFD must be operating with at least with the airspeed, altimeter and engine instruments for even Day VFR, and except for the VSI readouts, both PFD/MFD and the standby instruments must be fully operational for IFR. So this C172 could be grounded totally.

I heard that on the Diamond DA40, the AFMS for the G1000 requires both PFD and MFD displays to be operational but you can fly day VFR with an AHRS failure.

The concern would be that if a flight is illegal before even getting off the ground then you definitely won't be insured, and in this kind of situation is it rather likely that somebody (like... the avionics dealer you are flying to) will know about the problem.

So far, with 9 G500/600s completed in 20 months, we've had NO failures.

Based on informal user surveys I have seen from the USA, that is to be expected on 9 units of a G500.

[wigglyamp]

Not all glass-cockpit systems include engine gauges. The Garmin G500/600 and Aspen EFD1000 don't. For those wanting a comprehensive upgrade with glass PFD and engine instruments could use the EDM930 from JPI for the engine display (bit of an issue with EASA but this can be resolved).

[Fuji Abound]

Yes, you would fly back under VFR if the POH allows it


but I dont think it can.

Under the FARs for example 91/205 T and P s are required for each engine (stand to be corrected). On most glass aircraft you have neither if both screens have failed.

As I said earlier I think you would want a dial T and P as an after sales extra to assure VFR flight following a double field failure of the PFD and MFD.

[IO540]

However, if the glass versions of the T and P gauges are the primary, and the standalone gauges are only backups, then with a glass failure you cannot depart, because the primary ones have gone.

I am speaking of legality only. Practicality is a different thing...

[madlandrover]

Garmin do this quite nicely with the G1000 (no idea about the other versions, I've only used G1000 so far) - if one screen fails the data is prioritised, so assuming at least one screen is working you will keep AI, ASI, Altimeter, HSI, most engine gauges, and at least a small inset nav screen. The ones I was flying did have a small amount of intermittent failures, leaving me to realign AHRS in flight once (yes, it will - just!), and are very sensitive to battery voltages pre-start. Otherwise a very nice avionics system, IMHO superior to Avidyne's Entegra (although our aircraft haven't been upgraded to R9 yet) in terms of capability, but trickier to learn on initially. Horses for courses...

[IO540]

I have no issue with continuing a flight following an in-flight failure (at least, it's a very different question); it is purely the legality of a departure with the stuff INOP on the ground, and assuming somebody has been notified so you can't pretend it happened in the air ;)

I like the G1000 too; I have 1.5hrs in a TBM850 with it, and didn't have the slightest issue with it.

[Fuji Abound]

However, if the glass versions of the T and P gauges are the primary, and the standalone gauges are only backups, then with a glass failure you cannot depart, because the primary ones have gone.


I dont follow that line. If you have another dial T and P gauge installed why would it be any more of less primary as needs arise. No distinction is drawn between the AI on the PFD and the dial AI.


IMHO superior to Avidyne's Entegra

I think the dual screen feature of the G1000 is an important advantage it has over Entegra, however that aside I am now less certain there is much between them. Entegra is more intuitive, the G1000 might look more pretty. I cant think of anything one does that the other doesnt. R9 is imo the best yet.

[nav3]

I have a C182T with G1000/GFC700 A/P and have logged over 400hrs with G1000. About 6 months after purchase in 2009, I was having an IMC lesson at 3500ft (in actual IMC) and a 'Red X' suddenly appeared on the PFD with loss of AI, DI, ASI, GPS and altitude. Reversionary mode had no effect as obviously there was a more serious issue.

My instructor (who was not as well versed as I am in G1000) said" now what" ? At which point I went to standby guages and descended to VMC and returned to base VFR but whilst doing that all other general information appeared 'alive' but comparing the ASI with standby, alt tape with standby altimiter there was certainly corrupt data so best to ignore all information coming from the screens. Recycling would not work and it was obvious an AHRS / ADC failure of some sort. Absolutely fantastic practice to actually have it for real AND in actual IMC certainly gives some confidence to you (and makes a good impression on the instructor) !;)

Following calls when I was back on the ground to Cessna and Garmin, I deduced it was a 'known issue' with certain serial numbers of G1000 AHRS / ADC units ! What I found out was that a 'reworked AHRS unit' had actually been put in a NEW aircraft !! Garmin did incur my wrath but they WERE helpful and understanding !!

As I was still with the other 'primary tackle' at my disposal, although obviously most stuff was 'inop', I flew it to a well known avionics Garmin authorised dealer, on a lovely VFR day from Coventry to Gloucester and the AHRS unit was swopped within 60 mins. Flew back no problems.

10 months later, and just before my IMC test and AGAIN in IMC at 4000ft, the SAME THING happened only this time all the base information disappeared from the PFD and the MFD. I had experienced a total screen failure in my C172 G1000 before in 2007 when it went completely blank, but this time the screens remained on and visible but with corrupt information on AI, DI, HSI, GPS etc.

Again, back to base and called Garmin to advise. I did some detective work and found the batch of serial numbers of the defective AHRS units only to find I had had yet ANOTHER 'reworked' AHRS unit fitted !! Stern discussions took place between myself and Garmin and eventually I went to Glocester again and was guaranteed that I was now having a brand new AHRS unit fitted. Software upgrades / changes were necessary as mentioned if the ADC / AHRS units are changed but that was without issue. Touch wood, no further AHRS / ADC trouble and the G1000 with GFC 700 is a delight to fly.

My point is, it really does depend upon the 'type' of 'glass failure' as some engine data can still remain, so again legalities do come into it but there are so many practical issues that each 'failure' is certainly to be judged upon it's own merits. IFR would CERTAINLY be out of the question.

Obviously with the Avidyne units being driven by 2 x 430's that has it's benefits but for my I would never part willingly with my G1000.

The reversionary mode did not help me on either occasion but for some people I know who had blank screen failures, that is straightforward enough as it reverts to the MFD panel on the right.

Garmin and Cessna reacted well and apart from small audio panel issue with COM2 he flies like a dream. G1000 is easy to operate and I would choose G1000 over Avidyne any day although I have not yet played with R9 so cannot comment yet on that.