Partial panel

[Fuji Abound]

You have a working AI, magnetic compass and altimeter - nothing else including engine instruments.

You are IMC with a base 600 feet and a localiser approach available over land with no sea nearby.

In the first scenario you have a working radio and in the second you dont.

How would you approach the landing?

[GusHoneybun]

fuji,

your scenario doesn't describe partial panel. that is when you loose your vacuum instruments, ie DI and AI. in that case your workload is much higher.

taking your scenarios though,
first, make sure you are above MSA. if not then full power and pitch the nose about 5 degrees up and climb. then, turn on your pitot heat as it sounds like this has iced up .

if you have a working radio then request assistance and vectors for the nearest SRA or PAR unit. this should be your first request. let someone else worry about your tracking and leave you to the difficult task of flying the thing in a straight line
just follow their instructions. they will give you left 10, right 20 type heading corections. so, remembering compass turns, it's either 3 seconds rate one for 10 degrees, 6 seconds for 20, so on. for rates of descend, try counting to 6 and seeing how much height you've lost. times this by 10 and you have a RoD.

now, if you dont have a working radio, then climb above MSA (if not there already) and make you the beacon overhead. set 7600. if you have file a plan and have given an EAT for the overhead, then thats when you start your approach. before you get to the beacon, check your compass heading and work out how long you need to turn to get on the outbound heading. at the beacon, turn onto your outbound heading. hold wings level and ball centred and check against the compass. wait. after about 2 miles outbound, you will begin to see whether you are left, right or on the outbound radial. the tricky part is to stay on the outbound radial or localiser. don't chase the needles and if you start to drift left or right then turn 10 degrees or three seconds) the other way, level the wings, check the ball and wait. you will then see either the radial/localiser move back towards the centre in which case, once the radial/localiser is centred, then a small turn back should help keep on the outbound radial or centreline.
the base turn will normally require a turn of about 210 degrees. so thats about 70 seconds at rate one. start the base turn and stopwatch. roll out on your expected heading and wait to see the effect on the localiser. again, if you're left, then turn right 10 degrees, wait and see the effect. once happy with your heading/tracking and reasonably well established on the localiser, then drop the flaps, set a lowish power and pitch the nose down about 2-3 degrees. check your not below heights on the profile and try and descend the aircraft as quickly and safely as possible. calculate and check your RoD. at 90 kts you want about 450 fpm for a three degree approach, however, the quicker you get down to MDA the better as once you are visual, the drama ends. of, and i would use the published MDA, not any of the IMC rating add 200 ft to your MDA nonsense.

if you don't have a radio and any radio navigation gizmos, then it is indeed a bad day for you. personally, i would climb to MSA, head due east for at least 90 minutes (fuel allowing for this of course). this should put me over the sea, then descend at a low RoD. the problem with this is that I would have no idea of the QNH over the sea so I would probably wind off 10 millibars from the altimeter as a fudge factor. hopefully you will get visual with the sea before you hit it. then turn back to blighty, and land at the first field you find.

i'm not saying it will be easy but it shouldn't be impossible. just don't panic and if you're not at all sure then climb the buggah back to MSA.

[IO540]

I would reach for my handheld GPS and handheld radio and sort myself out with a DIY GPS descent somewhere, or get help from a radar unit if you can find one.

That's the obvious answer.

In your scenario, Fuji, I can't see there are any options if non-radio, and if you have a radio then you would get a radar letdown somewhere.

If truly out of options, all one can do is set up a minimum descent rate and descend, very slowly, and hope for the best.

Not sure how the localiser approach is relevant if you don't have anything with which to receive it.

In the UK, you will never be far from the sea so a timed leg offshore would be worth trying.

[Fuji Abound]

GHb

Thanks for your interesting reply.

Sorry I should have said this is a glass panel failure type scenario.

You only have AI, mag compass and altitude - nothing else - except maybe the radio.

(Loc only mentioned to give an indication of what assistance ground based radar might be able to give - accept that they may have a localiser without radar)

[englishal]

I suspect the glass cockpit has gone kaput. Has the backup ASI also gone?

S&L flight should not be too much of a problem, you can guestimate speed based upon common power settings.....egine sound / pitch / altimeter / known lever positions etc......

1) Request a PAR or SRA. If not available vectors to the FAF of the Loc approach and descend to correct altitude. At this point and altitude start descending down to minimums with radar guidance if available, or if not heading inbound course (which is protected with regards to terrain down to minimums). Come down quickly in this situation.

2) Pull the chute ;) Or pull my handheld GPS from the bag. Navigate to a the FAF of the loc approach and descend to required altitude, head on course using the handheld GPS, at the FAF start a descent down to minimums, or and make a perfect landing in time for tea and crumpets.

Do we not have any sort of nav kit in scenario 2? If not then you have to dead reckon your way to the FAF, whcih would be pretty tricky.

[gcolyer]

I would reach for my handheld GPS


You love your GPS:)

Out of Interest do you do much flying without it?

[Captain Smithy]

You have a working AI, magnetic compass and altimeter - nothing else including engine instruments.

You are IMC with a base 600 feet and a localiser approach available over land with no sea nearby.

In the first scenario you have a working radio and in the second you dont.

How would you approach the landing?


Well, I would start by praying!:uhoh:

[englishal]

Here is an interesting ditty....

Lets say the backup AI had also gone through a mechanical failure and you are in a G1000 aeroplane? What would you do then ;)

[soay]

Lets say the backup AI had also gone through a mechanical failure and you are in a G1000 aeroplane? What would you do then ;)
Curse your luck, then get your GPSMAP 2/3/496 out of your bag set it on its instrument panel page? ;)

[IO540]

gcolyer

I am not taking this bait anymore, so why don't you just give up?

FYI I was up at 5000ft today drilling holes in clouds, at -4C so with the prop de-ice on MAX, doing lazy eights, and was using the GPS to ensure I was in the right bit of airspace.

What would you do in the situation Fuji describes? Let's stick to posts that broaden knowledge, shall we? This isn't the Flyer forum.

[denhamflyer]

Interesting scenario.

Please remember the G1000 (and other Glass pannels) are NOT one system. Just like flights instruments (clockwork) are NOT one system. But they have connected parts. So the whole system does not just fail.

e.g. Each Pannel on a G1000 has independent GPS, Radio, VOR and Fan's.

You need to look at failure as you would for normal instruments (e.g. vacum)

This is likely to be:

AHRS (only one!) - use backup AI and Mag compass
Pitot - (only one - normally) all airspeed use GPS + feel when landing
Audio Panel (Radio should auto set 121.5)
Single Panel (Reversionary mode) - Minor issue here is loss of moving map but still have 1 GPS , 1 VOR and 1 Radio (or two if some wierd fault)
Fan dead - shut down the appropriate panel - then as above.

If you cant get there before the battery dies or smoke (fan dead but you didnt know) then im with IO - get the backup GPS out of the bag and portable radio.

(I've often wondered how good the ones with VOR support are?)

[soay]

Please remember the G1000 (and other Glass pannels) are NOT one system. Just like flights instruments (clockwork) are NOT one system. But they have connected parts. So the whole system does not just fail.
Unless the electric master switch or the battery master relay fails. Check the appropriate circuit diagram.

[denhamflyer]

I'll check - but I have two master switches, one for each source.

Just checked - yes I have two power systems (Cessna 182) Alternator/Main Battery & Standby Battery which will operate with the master switch off (if it was armed at start) - this powers an "Essential Bus"

[soay]

I have two power systems (Cessna 182) Alternator/Main Battery & Standby Battery which will operate with the master switch off (if it was armed at start) - this powers an "Essential Bus"
Sounds like a better design than some.

[IO540]

denhamflyer

I know nothing about the G1000 internals but would be suprised if it has two separate backlight and backlight inverter systems.

I've had a number of laptops fail over the years and in most cases it was the LCD backlight that went.

I think one must assume that a failure will take out the whole panel.

[S-Works]

Well I have 2 electrical systems on my aircraft, one powered from the standard electrical system and one that powers the nav kit that is a Nmh battery, so if I lost the main system I could flick the switch and use the backup system.

As far as having a go at IO540, I would wager that he knows where he is ALL the time!! Don't assume that because he embraces modern technology he does not know the basics.

[Miserlou]

"How would you approach the landing?"

Very carefully!

As Gushoneybun said, this isn't a standard failure scenario as the altimeter should also have failed.

Fly the aeroplane at the speed it is currently trimmed for and consider making a flapless landing to avoid configuration changes at low level.
Expect to stay on instrument to below the MDA for the approach (avoids stress when the ground doesn't appear at 600').

Get vectors for an SRA or PAR.
If none within range, find a VOR approach, probably be easier to identify the overhead position. Fly to the beacon and make a time based procedure.

When descending, maintain the trimmed speed until visual references have been established. You should know the approximate power setting for descent but just reducing by 3-500rpm should be enough to let you fly at the trimmed speed and an attitude 2 or 3 degrees below the horizon.

Needn't be a big deal.

[soay]

I know nothing about the G1000 internals but would be suprised if it has two separate backlight and backlight inverter systems. I think one must assume that a failure will take out the whole panel.
The PFD and MFD are identical, independent displays and if one fails, the critical information is presented on the remaining one. This should happen automatically, but there is a backup switch, just in case, and for testing it works.

[aluminium persuader]

I'm astonished that so many people are mentioning vectors. You say "Pan-pan, pan-pan, pan-pan. I have multiple instrument failure, request a no-compass, no-gyro recovery for SRA"
That gets you identified, an appropriate radar service and "adopt the standard no-compass, no-gyro procedure; all turns rate one, starting and stopping on the executive word now"

You fly the plane, ATC do the work. :ok:

[Fuji Abound]

I had in mind a DA42 as my example.

The backup instruments are the AI, magnetic compass and altimeter. The AI is electric. There are no other backup instruments and no other radio navigation aids. (Other than whats in your flight bag). There is no manual engine instrumentation, although of course there is manual rudder and elevator trim, flaps and gear (although flaps and gear are electric, but dont worry if you run the backup battery dry because with diesels both engines are going to stop at that point anyway).

Primary systems can be displayed on either panel in the event one fails.

As IO540 says (perhaps in the very unlikely event) both backlights failed all the G1000 systems would be worthless (because there would be nothing to see if they were working). I am still researching the consequence of full AHRS failure (effectively the central computer through which the majority of the avionics operate).

However unlikely it is, a dual panel failure is what provoked my interest.

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!!! :) ).

Perhaps it was in the mind of the designers that the backup instruments are only there to deal with selective failure of individual G1000 units (which after all is modular) - for example the loss of the glass AI.

Alternatively maybe it was in their minds you could survive on just the backup instruments which is what provoked my question. If that was so it might be odd that they did not also include a G/S perhaps - opinions please.
Of course I appreciate it is a cost versus risk scenario equation but for a "serious" IFR platform costing a very substantial sum a backup G/S is a very small percentage of the whole package.

(Personally I dont go any where without a GPS and radio in my bag - sorry if I fall into the pro GPS group, and as it happens I even put the liferaft in any twin I taking over water in spite of the ribing I always get).

[denhamflyer]

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!

[mad_jock]

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.

[drauk]

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.

[denhamflyer]

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.

[Fuji Abound]

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.

[denhamflyer]

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 :ouch: ). 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.

[tmmorris]

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.

DnD have phone numbers - I don't have them to hand but they're programmed into my mobile. I think I got them from an AIC. In the event of total radio failure they're my fallback.

Tim

[englishal]

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!!! ).
Assuming it is just the screens that are dead....just hold down the frequency change over button for several seconds and it tunes the radio to 121.5.....I believe the radios go to 121.5 in the event of both systems failing completely.
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? ;)

[IO540]

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.

[soay]

FWIW, Garmin's G1000 Trainer software does let you simulate failures of any of the components, so the effects needn't come as a complete surprise in flight.

[Il Duce]

tmmorris - good idea to have the D&D phone number in your mobile in case of RT fail.
aluminium persuader - why say "pan" six times?

[soay]

why say "pan" six times?
From CAP 413:
1.2.2 The pilot should make the appropriate emergency call as follows:
a) Distress ‘MAYDAY, MAYDAY, MAYDAY’
b) Urgency ‘PAN PAN, PAN PAN, PAN PAN’

[mad_jock]

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?

[tmmorris]

OK, don't stake your lives on this but I have:

D&D London: 01895 426150
D&D Scottish: 01292 692380

Tim

[Il Duce]

D&D London number is correct above.
soay, my apologies, I was going by the back page of the FIH which quotes PAN x3 followed by callsign.