Dual fmc failure

[wilco77]

Dual fmc failure in radar environment, ie. Malaysian airspace over India, what does ATC need to be informed?

[HPbleed]

If this was me, I would make a Mayday, loss of navigational performance, loss of RVSM etc, would require radar headings, probably to nearest suitable airfield where the problem can be fixed (so need onward travel for pax, an engineering department - perferably used to dealing with company aircraft).

[Pugilistic Animus]

A Mayday???

But,

Where's your emergency? :eek:

[HPbleed]

The fact that you're no longer LNAV and VNAV compliant? Please, correct me, I'm still learning these things!

[Pugilistic Animus]

wilco77

HPbleed

I think you would just---say unable RVSM--etc.

but you should still have IRS capability on raw data STBY NAV [ususally] no
you wont lose ALL area navigation---:)

Bruce Wayne I don't think they are 'trolls', It is a genuine question...sometimes folks were not taught or just don't know-we don't want to put pilots off from coming here and asking genuine questions---:)

[Bruce Wayne]

PA,

Fair enough.. post removed :ok:

[johns7022]

By FMC I assume you mean FMS....like loosing your GPS, or GNSXL....

Um....well if your going direct...and now you have to fly by VORs, ADF, DME, ect....not an emergency...your just going to have to start pulling out charts...and using other means of navigation....

Going from SFO to Hawaii, would probably be an issue...

I always bring a little hand held GPS with me....

[Joshilini]

Why would you declare a mayday?

Switch to manual flying and request vectors to the nearest suitable airport (suitable -- up to your very own interpretation there). No offence but have a lot of airline pilots forgotten how to fly manually? "Gear up and switch on the autopilot will you?"

[Type1106]

Surely, a navigation failure of this kind would require a Pan Pan call as neither the aircraft, its occupants nor anyone else is in 'immediate need of assistance'.

If you are in a radar environment then it is now the controllers job to take whatever action he deems necessary but you should still be able to navigate using VOR/DME. Also, I'm pretty sure RVSM compliance is not dependant on nav input but I'm prepared to be corrected...

However, if you are out of ground navaid and radar coverage and you are lost then 'Mayday' would be appropriate.

BTW 77, I'm a little confused about your scenario 'Malaysian airspace over India' - last time I looked Indian and Malaysian airspace were not even adjacent.....

1106

[TolTol]

Declare to ATC "unable Rnav", RVSM should be unaffected. No mayday, no Pan, just continue using vectors or conventional navigation to destination. Should be no need to divert, unless the destination has Rnav approaches only and no radar (have never seen this).

I'm talking about operations in Europe though. MNPS airspace I'm not familiar with.

[King on a Wing]

Dual Fmc fail....
Unable RNP....infm ATC of degraded navigation performance. Consider making a PAN if in non radar environment. Try and request radar headings. All your route prior to the failure would have been copied onto your Cdu(s).Therefore following the route would be NO PROBLEM. However any new waypoints would have to be added using Lat/Long posn. Lnav/Vnav will not be avbl,however Lnav can be re-engaged later using old route. Basically revert to using good old INS system procedures.All radios ie Adf's and Vor's will have to be manually tuned thru Cdu's for navigation. No Vref/Vapp avbl.So open the ol handy dandy and dust those performance pages...
Most importantly land back at an airfield with the closest bar...:)
I got a feeling you'll need the drink!

[BOAC]

All a bit confusing since we have no idea which a/c we are talking about, but I think the only thing that could affect RVSM would be if the particular A/P required an FMC to function in basic height hold.

King - into which piece of kit are you planning on entering waypoints via lat and long and exactly what do you expect to get out of it afterwards?

As type 1106 says, you are already 'lost' before the failure:)

[B777Heavy]

I agree with BOAC here...not sure why you would not be RVSM compliant? FMC(S) failure has nothing to do with Height or Alt hold

[oceancrosser]

King on a wing has it spot on. You should even be MNPS compliant with at least 2 cdu´s/IRS´s working. More workload, but a lot less than the old 9 point INS. If not revert to the "blue spruce" routes or down to FL270 and continue. Might need PAN to get some attention in that case. Nothing at all to do with RVSM.

[Pugilistic Animus]

I don't even understand the thread anymore--RNP-RVSM RNP-MNPS which one?:}

whenever you can't do something---say 'unable'


:ouch:

[BOAC]

Unable:):)

[latetonite]

I wonder how I survived for 25 years without even one FMC onboard...but I understand that many of the new generation pilots` best option is to declare a PAN to start with..

[Dream Land]

I agree with BOAC here...not sure why you would not be RVSM compliant? FMC(S) failure has nothing to do with Height or Alt holdWell on the small bus Dual FM Failure would kill the A/P, please correct me if I am wrong, and that would mean no RVSM.

[BOAC]

FMC(S) failure has nothing to do with Height or Alt hold - there you go:ok: Never say never (as Marilyn Monroe used to say)

[MrBernoulli]

The following is taken from a Honeywell manual for the B777 FMS system. Fairly recently practised this in the sim - it is a bit startling initially (so many pages you are used to using are suddenly gone) but manageable.

I think BOAC, posting above, may have confused FMS with CDU - they are not the same thing. The CDU (boxes in the cockpit) controls inputs to, and feedback from, the FMSs (bigger boxes downstairs in the E & E bay). :ok:

Boeing 777 Flight Management System

ALTERNATE NAVIGATION

If both FMCs fail, .......

Initializing alternate navigation does not require any pilot action. It occurs automatically 2.0 seconds after the last FMC fails. Alternate navigation initializes using the last flight plan and last set of navigation radio frequencies downloaded from the FMC prior to FMC failure. Alternate lateral guidance is not enabled for an additional 3.0 seconds after alternate navigation initializes. Alternate navigation radio tuning is available as soon as alternate navigation initializes.

All CDU calculations are based on a great-circle course between waypoints. The CDU does not accept undefined waypoints or conditional waypoints. Complete departure or arrival/approach procedures cannot be manually entered or crossloaded from the FMC if they contain undefined or conditional waypoints. The CDU creates a discontinuity between such waypoints. However, individual legs of a procedure can be manually entered or crossloaded if they constitute a great-circle course.

Route changes are made on the ALTN NAV LEGS page the same as with normal FMS operations. All courses between waypoints are direct routes. Modifying the active waypoint computes a present position direct course. A route change to any one CDU crossloads the route change to the other CDU when the change is executed.

Only the active waypoint course can be referenced to magnetic north because the ADIRU can provide magnetic variation only for present position. All subsequent waypoint courses are displayed as true courses.

The radio must be manually tuned on each CDU in alternate navigation. The left CDU tunes the left VOR, DME, ADF, and left and center ILS. The right CDU tunes the right VOR, DME, ADF, and right ILS. In all cases, manual radio tuning is done on the ALTN NAV RADIO page.

The alternate navigation system operates from three CDU pages:
ALTN NAV LEGS page
ALTN NAV PROGRESS page
ALTN NAV RADIO page.
These pages are the only ones available in the alternate navigation mode. Executed flight plan modifications made on one CDU ALTN NAV LEGS page are displayed on the other CDUs

[NEWYEAR]

Hi.:)

If your plane is certified to fly in RNP-10 (very popular in Boeing), in my modest oppinion you don´t need to say anything at all.

You will have to take into acount the abnormal procedures as you have read above from the rest of Ppruners.

You are not in a situation of May day, Pan etc etc etc. Keep calm and take it easy.

Regards.

[BOAC]

So - it was a 777? Wat about an ATR? An Embraer? A TU. Lets take a 737 Classic - 2xFMC fail - out with the paper stuff. No waypoints, no present position, no 'navigation', no perfomance data. You will have a lat and long position on the INS panel so you'll know where you've been. .All maneagble, however, of course. 777 a bit smarter.

may have confused FMS with CDU - no - the question was about the FM Compouter, nor the FM System. I never even considered an FMS.failure - the FMC is just one part of the FMS

[Permafrost_ATPL]

The nice TRE a few weeks ago failed both FMGCs on an A320. Then our slats jammed during the procedural approach ILS into Malpensa. The extra fun bit? The loss of both FMGCs mean you don't get VFEnext displayed, so you better start writing down VFEnext-5 for all your flap stages. While trying to remember how you manually tune the radios :ok: Of course no A/P A/T.

Oh, and procedural ILS was due to the radar having been knocked out by the storm over the airport (and all the alternates). Needless to say, a missed approach would have been interesting (for those of you who know MXP...).

Skipper and I fell asleep about 5 minutes after getting into the taxi from the sim building :)

I know thread drift, but worth sharing a beautiful sim moment.

P

[Manual Reversion]

Funnily enough, I had a dual FMC failure at about 30W. returning to the UK yesterday morning. A few alerts, a/p, a/t drop out and a few odd FMA annunciations, put newspaper down, engage hdg sel, alt hold, carry on. FMC's elected to rejoin the flight twenty min later.(747 a/c).

[wilco77]

Thanks all for your inputs.
I do agree there is no need for a may day call, and your rvsm should not be affected depending on the type of aircraft. Some aircrafts do allow you to reengage the autopilot.

[GlueBall]

And if ever you're mid Pacific and lose all your FMC(S) and all nav capability, you could (B747) still select A/P, ALT-hold, select HDG bug and steer magnetic course according to your computer flight plan way points data. Imagine! :ooh:

[PantLoad]

Once we lose F/D, A/THR and A/P, we're all dead!!!!
(Simple fact!)

Fly safe,


PantLoad

[GlueBall]

Once we lose F/D, A/THR and A/P, we're all dead!!!!
(Simple fact!) . . . not in the B747, unless you're a cadet pilot!

[B777Heavy]

Today 03:57
PantLoad
Once we lose....
Once we lose F/D, A/THR and A/P, we're all dead!!!!
(Simple fact!)

Fly safe,


PantLoad


Ermm why?....:ugh::confused:

[M2dude]

Manual Reversion

Funnily enough, I had a dual FMC failure at about 30W. returning to the UK yesterday morning. A few alerts, a/p, a/t drop out and a few odd FMA annunciations, put newspaper down, engage hdg sel, alt hold, carry on. FMC's elected to rejoin the flight twenty min later.(747 a/c).

Seems to happen every now and then with the Honeywell FMC fitted to the 744; an FMC glitches, and both FMCs seem to snooze while the 'good' one attempts (usually successfully) to re-synch the 'glitcher'. Far less common on the 777, where the FMC is in fact an FMCF within AIMS, and is inherently far more reliable.

Dude :O

[BOAC]

B777 - I think Pants was being humerous.

[bArt2]

B777 - I think Pants was being humerous.


Oooohh don't you know, that's not allowed over here. It's written somewere in the ROE :E

[Callsign Kilo]

737NG - Dual FMC failure, no longer PRNAV/BRNAV. RVSM Maintained. A/P will not disengage, however LNAV and VNAV cease to function obviously. ALT HOLD Maintains altitude, HDG SEL for radar vectors and VOR/LOC for pretty much everything else. Set up ref and N1 limit manually with the selectors situated above the upper DU and refer to the QRH PI for the figures. Had it in the sim 8 months ago. :ok:

[rudderrudderrat]

Before FMS was first introduced into TriStar operations - we were very happy with Radio Nav (VOR etc) around Europe, INS display for Long Haul Ops, (Cross Track Error & Desired Track) & Manual Thrust in the cruise everywhere. After the intoduction of FMS, some wondered how we had coped before hand.

Only Airbus could design an aircraft which fails the autopilots when the FMGCs fail though.

[King on a Wing]

In addition to my last thread:
Dual Fmc fail over Pacific....no issues again.
Last route is already in the box. Use Alt hold on AP,then Track sel to fly the magenta(which should already be displayed on your ND due no erasure of waypoints not passed already). If you are on the magenta,use Lnav. Vnav will not be available. Only problem arises if you wish to divert to an airfield which would be beyond Vhf coverage of your Vor's(typically on trans pacific routes!).In which case you've got to punch in the coordinates of the airfield in Lat/Long mode and you will get the magenta to fly you direct to the airfield in question.After that its simply a matter of engaging Lnav. Like someone said earlier,no Vspeeds or maneuvering speeds.Therefore the handy dandy...
Off to mah beer now...:cool:

[PantLoad]

Yes, joking, of course....


Fly safe,

PantLoad

[BOAC]

Naughty boy, PL!
"Looks like we had a single SOH failure there, Skip"

[Spendid Cruiser]

If your plane is certified to fly in RNP-10 (very popular in Boeing), in my modest oppinion you don´t need to say anything at all.
I'm not really sure on this as I don't fly RNP-10 oceanic airspace and neither are our aircraft so equipped. As far as I understand is, if you don't have an FMC to generate an FMC position from the IRSs and the GPS then you cannot be RNP-10.

[john_tullamarine]

we were very happy with Radio Nav

.. and, if all else fails (as it often used to do on the Electra from Oz to UnZud) the radar works real fine to find the coastline.

If that failed the cloud gave the place away anyway.

[Checkboard]

From some notes I wrote up a while ago for 737:

Failure on the ground or for a return to base:

MEL 2-34-27 applies
Our OPS MAN require MNPS routes to "be avoided"
Flight without MNPS is not normally permitted in B-RNAV (RNP 5) airspace, but it is usual to obtain approval to proceed to a repair airport with ATC approval. (Jeppesen text, ATC pages 551-554)
Repetitive Flight Plan (RPL) must be cancelled, and a new plan filed with "S & R" in item 10 removed and "STS/NONRNAV" entered in item 18
The phrase "Negative RNAV" must be appended to each radio message initiating contact with each new ATC frequency.
Take-Off and climb: standard schedule (280/0,79 for -300 or 280/.78 for -700)
Required to manually set N1 bugs. On take-off set take-off thrust on PF's bug and MCT (for engine failure) on PNF's bug.
Autothrottle not available for take-off. Climb power is available by setting autothrottle to arm and pressing N1 selector at acceleration altitude.
Pitch modes available: TOGA, LVL CHG and V/S (ie no VNAV)
Above FL150 disengage autothrottle (or deselect N1) and periodically bug & set the climb N1 on both N1 gauges as per the MAXIMUM CLIMB % N1 page in the QRH (As the PMCs are using engine inlet temp & pressure data, and being conservative, a significant performance degradation occurs in the climb thrust if you leave the autothrottle engaged without climb performance data from the FMC.)
standard cruise speed from QRH (LRC in our company, but fixed Mach for others)
Approaching cruise level extract target N1 from QRH FLIGHT WITH UNRELIABLE AIRSPEED/TURBULENT AIR PENETRATION (CRUISE) chart and bug this on PFs N1
Extract limit N1 from MAXIMUM CLIMB % N1 QRH page and bug on PNFs N1
Autothrottle may be used to maintain cruise.
Inform ATC not RNP compliant.
Approaching descent, calculate top of descent point QRH 0.74/250 DESCENT SPEED (ALL ENGINES) chart
Prior to descent, set the Vref speed using the QRH VREF Chart
Once the ATIS is received, set the N1 bugs to cover a missed approach from the QRH GO AROUND % N1 chart.
Standard descent schedule (0.74/280/250)
Auto-throttle can be used for descent & approach
In the event of a missed approach, pushing TOGA will cause the auto-throttle to disengage. Manually set thrust, The flight director will display correct TOGA commands.


Experience shows that most FMC failures are of short duration, so it's worth checking it periodically by selecting INIT/REF or similar to confirm its status.

[NEWYEAR]

if you don't have an FMC to generate an FMC position from the IRSs and the GPS then you cannot be RNP-10.


Yes you can be RNP-10. In the following cases:

6.2 hours after placing IRU in navigation mode (pure inertial), or
5.9 hours after the last automatic DME/DME position update, or
5.7 hours after the last automatic VOR/DME position update.

The FMS continuosly monitors input from the available naviagtion sensors (radios, IRUs, and GNS) to compute a position and actual navigation performance "ANP" value in units of nautical miles. The FMS RNP function is used as a integrrity monitor for airplane position.

If the plane is certificated to fly in RNP-10 airspace then, you can fly without GPS for a flight time not to exceed:
6.2 hrs.
5.9 hrs.
5.7 hrs.

[GSMini]

Well, on the bus, you will lose A/P, FD and A/THR. So nope, you´re not RVSM.

It´s not a mayday, but a few unable RVSM and RNAV are mandatory. Just fly it manually, use stand by nav, and fly the acft as a conventional one, while trying to recover at least one FMGS doing resets. And of course, ask for vectors if you are under radar control.

It´s actually good on long flights to practice a little bit with the VOR´s, knowing what radial are you in, how will you get in a holding from X radial, how will you intercept that other radial outbound...It really helps.

Nice to have been a FI before the bus :)

[Ocampo]

while trying to recover at least one FMGS doing resets.

Does that involve hitting Ctrl+Alt+Delete somewhere? :)

[FE Hoppy]

It wasn't that long ago that we plodded home to Ice station kilo with no compass no giro from the med.

How times have changed!

[JammedStab]

Is it written down anywhere official that at least one FMC is required to enter RNP-10 airspace?

[Stone_cold]

PRO SPO 51 page 2

[JammedStab]

Thanks,

This is an Airbus specific document. I think Boeing allows only 1 FMC but can't find anything official.

[FE Hoppy]

How can you navigate with reference to IRS if you don't have an FMS?
You need not only position accuracy but also flight technical error accuracy. Unless your avionics can bypass the FMC and display deviation from IRS(INS) DTRK you cannot fly RNP-10 without an FMS.

[JammedStab]

How can you navigate with reference to IRS if you don't have an FMS?
You need not only position accuracy but also flight technical error accuracy. Unless your avionics can bypass the FMC and display deviation from IRS(INS) DTRK you cannot fly RNP-10 without an FMS.

Thanks,

The CDU replaces the FMC for reference and uses Alternate navigation. It is more cumbersome but we still have navigation capability. Sort of like in the old INS days without a database where any waypoints are entered by lat/long. Other restrictions apply as well but we can continue to navigate.

[8che]

Of course aircraft type is crucial here.

For info on B757/767/787/777/747 you still have full CAT3B autoland capability with total FMC failure !

RVSM is not affected by this either.

MNPS and oceanic ops are not approved without at least 1 FMC so would need your head examining to carry on and enter that airspace like this. Of course if already in then crack on as best you can.

BRNAV in europe which is RNP5 so thats gone with the FMC's.

The 787 has 3 FMC's.....so job done :O

[Natstrackalpha]

Can`t you use the VOR(s) "wassup doc?" If you are in RVSM can`t you request a non-RVSM and maybe get/need a re-release or am I talking out of my NDB - which you can also use if there are any left. It means you are now driving:) but you can stay in Selected mode and autopilot and well, easy life, you have just got to get on with the nav without any delay. You have your charts. Just do some work for a change.



>>>@pantload - you`re silly.

and, and, if you are truuuuuly lazy you can ask for vectors (if they can see you) and get them the ATC boys to do some work for a change. Seriously, though in reality everybody will be lending a hand, some will offer, others will have to be delegated, all in all the outcome will be brill - just trying to figure out the ILS bit - do we have an ILS? If not can we use VOR + DME - if no DME then find somebody who can a/. Navigate well and b/. can count.

Raw VOR with no dme in IMC would be interesting, kind of a bad weather circuit using a VOR - that`ll give aerodrome atc a run for their money - but hey there`s approach control, Approach Radar, life `aint so bad. the thing is you see - to go somewhere nice where they have such ATC facilities, like SRA and PAR with gorgeous bright runway lighting a nice set of ALSF-2 should be suffice and yummy vectors. Or, if you are too proud for vectors then QTE`s and QDM`s - being too proud for vectors though, is a bit like being too proud to accept Kate Upton`s invitation to dinner. Is it far to the sea? Are there mountains around? How about some high ground - this`d be interesting in MEX, but, but you can also use the AWR map mode . . thing . .mode, but if the FMGS is out then do we have AWR, must do . . except it, the awr display, lives on the screen and the screens may be out or the awr has its own dedicated screen. hmmm. You have to sort something out quick though you are travelling at 4.46 m/s which is shifting PDQ. A320. Ah, no a/p. . .well, thats no hardship in a bus which holds everything anyway.

@OCAMPO no, just close your eyes, delete the lot and it will all go away - not happening am afraid you actually have to deal with it - which means putting the chat up lines to the FA on hold and doing some real work, I know, I know, its a hard life sometimes . . . but best to be cuddly wuddly with the hostie at the end of the day and at the end of a long G&T rather than cuddling a freezing cold mountain now isn't it? so, the IRS, or INS in English, will still be working, giving nice things like, position and ground speed and wind.

While we are all here - they should spring this one on us in the sim, much more often, if necessary - it would make for a round-up to the day. Especially at the end of a successful session. After all, the proverbial always seems to hit the fan just when you are about to finish off your Mini Cheddars:/

[Lucky8888]

Well, I guess if I had a simultaneous failure of two FMS' (assuming there were only two), and considering each FMS is usually (always?) powered by separate electrical buses, I'd want to know what else doesn't work. This would almost be an impossibility without other failures somewhere.

[underfire]

Dual failure, no problemo...

Go in the cabin, find a laptop and log on thru the IFE....

Much better flight controls from there anyways.

[JammedStab]

Well, I guess if I had a simultaneous failure of two FMS' (assuming there were only two), and considering each FMS is usually (always?) powered by separate electrical buses, I'd want to know what else doesn't work. This would almost be an impossibility without other failures somewhere.

I know of a case where a software bug caused both to fail. The software was later updated by the manufacturer.

[JammedStab]

Of course aircraft type is crucial here.

For info on B757/767/787/777/747 you still have full CAT3B autoland capability with total FMC failure !

RVSM is not affected by this either.

MNPS and oceanic ops are not approved without at least 1 FMC so would need your head examining to carry on and enter that airspace like this. Of course if already in then crack on as best you can.

BRNAV in europe which is RNP5 so thats gone with the FMC's.

The 787 has 3 FMC's.....so job done :O
I am aware of that but don't know where to find this information. Could someone point it out to me. By the way, just the other day.....

"N662US, a Boeing 747-400 aircraft operated by Delta Airlines as flight DAL167, had departed Seattle-Tacoma Intl, WA, (KSEA) en route to Tokyo/New Tokyo Intl, Japan (RJAA). Approximately 60 nautical miles south southwest of Tofino, BC the flight crew declared an emergency due to a dual Flight Management System (FMS) navigation equipment failure. The aircraft circled south of Vancouver Island for approximately one hour to dump fuel in order to be within its maximum landing weight limitation. The aircraft returned to KSEA and landed without further incident.

The operator’s maintenance determined that the FMS was faulty. The number 1 FMS was replaced and tested, and the aircraft was returned to service the following day."

[Intruder]

For info on B757/767/787/777/747 you still have full CAT3B autoland capability with total FMC failure !
Not quite...

In the 744 there will be no autothrottle, so no Cat 3 capability for most operators. In any case, it is not "full" Cat 3 capability.

As for DAL167, while it is POSSIBLE to continue from SEA-NRT with a dual FMS falure, I would not consider it smart. Pilot workload would be increased significantly, including a HUGE workload increase in the terminal area at the end of a long flight. With so little tolerance for deviation from the norm these days, returning to SEA was a good move.

Also, while it might not be a true "emergency" situation that had high risk to life & limb, declaring an emergency is often the only way to get priority handling so fuel dump and return can be accomplished.

[CCA]

Not quite...

In the 744 there will be no autothrottle, so no Cat 3 capability for most operators. In any case, it is not "full" Cat 3 capability.

As for DAL167, while it is POSSIBLE to continue from SEA-NRT with a dual FMS falure, I would not consider it smart. Pilot workload would be increased significantly, including a HUGE workload increase in the terminal area at the end of a long flight. With so little tolerance for deviation from the norm these days, returning to SEA was a good move.

Also, while it might not be a true "emergency" situation that had high risk to life & limb, declaring an emergency is often the only way to get priority handling so fuel dump and return can be accomplished.

C'mon, without an FMC it's simply a "classic", a huge workload?? The QRH even says no LNAV/VNAV no A/T it certainly doesn't say land asap or at nearest suitable.

No A/T is no 3B, 3A is fine and it's still easier than flying the classic but less rewarding.

[JammedStab]

Not quite...

In the 744 there will be no autothrottle, so no Cat 3 capability for most operators. In any case, it is not "full" Cat 3 capability.

As for DAL167, while it is POSSIBLE to continue from SEA-NRT with a dual FMS falure, I would not consider it smart. Pilot workload would be increased significantly, including a HUGE workload increase in the terminal area at the end of a long flight. With so little tolerance for deviation from the norm these days, returning to SEA was a good move.

Also, while it might not be a true "emergency" situation that had high risk to life & limb, declaring an emergency is often the only way to get priority handling so fuel dump and return can be accomplished.
Just get vectors to final in the terminal area. No need to declare an emergency to dump fuel(normally) and no need to declare an emergency to divert to another airport.

But, it appears that oceanic airspace may not be allowed due to entry requirements of 1 FMC. (Please provide a link to show this). Would it make sense to consider a re-route further north onto a Russian Route in order to continue and perhaps refuel in Sapporo?

[Intruder]

No A/T is no 3B, 3A is fine and it's still easier than flying the classic but less rewarding.
Depends on the operator and their OpSpecs. We cannot do Cat 3 without autothrottle.

But, it appears that oceanic airspace may not be allowed due to entry requirements of 1 FMC. (Please provide a link to show this). Would it make sense to consider a re-route further north onto a Russian Route in order to continue and perhaps refuel in Sapporo?
You made the statement, so maybe you can provide the link...

Per our FCOM, an FMC is required for CPDLC/ADS-C operations and/or for entry into Class II Navigation airspace.

How long does it take to get overflight approval and an entry window for a Russian route?

[vilas]

For Airbus pilots
Dual FMGS failure need not be all of this. FMGS has two parts the FM part and the FG part. Try to engage the Auto pilot and ATHR if the FG is still available it will engage. If both have failed then try manual reset, if it doesn't work then if equipped with BACK UP NAV select that you have flight plan and some limited functions.

[JammedStab]

You made the statement, so maybe you can provide the link...


Gee, I wonder if I would be asking for a reference/link if I knew where it was.


How long does it take to get overflight approval and an entry window for a Russian route?



I guess you will find out when it happens. But may very well be worth the effort and if it doesn't work, at least you can say you tried if questioned about it.

[Romasik]

Talked to a pilot who was a crew member on a flight (his previous company) that was deliberately flown from the company base to destination and returned back with both FMGCSs inop. A320. 2 hours flight in radar and VOR enviroment. No AP, FD, A/THR, reference speeds, picture on ND, anything that comes from any part of FMGCS. First company flight to a new destination. TV reporters on departure and arrival. Of course ATC had no idea. In fact nobody had except the cockpit crew, maintenence and Fight Operations managment.
Cessna-320.

[Goldenrivett]

Of course ATC had no idea.
What did they file on the ATC flight plan under RNAV capability?
https://www.ippc.no/ippc/help_fpl.jsp

"Other reasons for special handling by ATS shall be denoted under the designator RMK/. PBN/ Indication of RNAV and/or RNP capabilities."

[Amadis of Gaul]

That was my question, too, Goldenrivett. At the very least, ATC SHOULD have been aware. Then again, if this was a conversation over a PBR at the hotel bar, I'd discount over 91% of it.

[FlyingStone]

Talked to a pilot who was a crew member on a flight (his previous company) that was deliberately flown from the company base to destination and returned back with both FMGCSs inop. A320. 2 hours flight in radar and VOR enviroment. No AP, FD, A/THR, reference speeds, picture on ND, anything that comes from any part of FMGCS. First company flight to a new destination. TV reporters on departure and arrival. Of course ATC had no idea. In fact nobody had except the cockpit crew, maintenence and Fight Operations managment.

Flying below MMEL for a publicity stunt. Sadly by far not the only company in this world that would do such things.

[felixthecat]

NEWYEAR quoted this a while back
Yes you can be RNP-10. In the following cases:

6.2 hours after placing IRU in navigation mode (pure inertial), or
5.9 hours after the last automatic DME/DME position update, or
5.7 hours after the last automatic VOR/DME position update.

The FMS continuosly monitors input from the available naviagtion sensors (radios, IRUs, and GNS) to compute a position and actual navigation performance "ANP" value in units of nautical miles. The FMS RNP function is used as a integrrity monitor for airplane position.

If the plane is certificated to fly in RNP-10 airspace then, you can fly without GPS for a flight time not to exceed:
6.2 hrs.
5.9 hrs.
5.7 hrs.

What aircraft is this for, and if not aircraft specific where do you find these details? Never seem them in the 777 FCOM or other documents.

I'm happy enough that on a 777 the loss of both FMC really isn't that big a deal since the CDUs have the current route and any arrival already programmed in their memory, plus ALT NAV lets you program via LAT/LONG. Positional info now just via ADIRU, and slowly degrades over time when out of nav beacon range.

777 just could basically continue (specific airspace dependent), still RVSM, inform ATC (No Mayday probably not even a PAN), and request radar vectors at the far end. Performance from the QRH plus the trusty 3x table.NATS/Oceanic and Polar however are another issue :)

[Intruder]

For the 744 (from our FCOM):

Two IRUs in conjunction with one FMC and two FMS-CDUs meet the
requirements as the sole means of navigation for flights up to 18 hours duration.

There are no time limits in OpSpec B036 or B039, as long as GPS or DME/DME updating is operational upon entering airspace requiring LRNS (Long Range navigation System), and dispatch requirements were met.

HOWEVER, such [lack of] limitations are operator-specific, per OpSpec B039:
c. Minimum Navigation Performance Capability Required. The certificate holder shall not conduct any operation in NAT/MNPS Airspace unless the certificate holder has satisfactorily demonstrated that the navigation equipment is installed and operational on any airplane used in NAT/MNPS operations. The procedures for use of this equipment must meet the following NAT/MNPS requirements on a continuing basis:
(1) The standard deviation (one sigma) of the lateral tracking error is less than 6.3 nautical miles (NM).
(2) The proportion of the total flight time in NAT/MNPS Airspace spent by aircraft 30 NM or more off the exact centerline of the assigned track is less than 5.3 x 10E-4 (less than one hour in 1,887 flight hours).
(3) The proportion of the total flight time in NAT/MNPS Airspace spent by aircraft between 50 and 70 NM offtrack is less than 1.3 x 10E-4 (less than one hour in 7,693 flight hours).
(4) Suitable displays must be available at each pilot's station to permit continuous monitoring of the long-range navigation systems cross-track and along-track information.

The 744 DDG simply refers to the FCOM Limitations section for Dispatch and entry requirements. Again, no specific time limitations for degraded systems AFTER entry.

[JammedStab]

Yes you can be RNP-10. In the following cases:

6.2 hours after placing IRU in navigation mode (pure inertial), or
5.9 hours after the last automatic DME/DME position update, or
5.7 hours after the last automatic VOR/DME position update.

The FMS continuosly monitors input from the available naviagtion sensors (radios, IRUs, and GNS) to compute a position and actual navigation performance "ANP" value in units of nautical miles. The FMS RNP function is used as a integrrity monitor for airplane position.

If the plane is certificated to fly in RNP-10 airspace then, you can fly without GPS for a flight time not to exceed:
6.2 hrs.
5.9 hrs.
5.7 hrs.

NEWYEAR quoted this a while back


What aircraft is this for, and if not aircraft specific where do you find these details? Never seem them in the 777 FCOM or other documents.

I'm happy enough that on a 777 the loss of both FMC really isn't that big a deal since the CDUs have the current route and any arrival already programmed in their memory, plus ALT NAV lets you program via LAT/LONG. Positional info now just via ADIRU, and slowly degrades over time when out of nav beacon range.

Check your 777 MEL under FMC and you might find the same or similar numbers to what is posted above. Also, any plans ahead of time for flap maneuver speeds, go-around N1, etc. How about all those gaps that may be visible between some of the waypoints in the STAR? Any plans ahead of time if ATC gives a different STAR? There are a few things to plan for ahead of time.

[extricate]

Any other considerations to think of? And thoughts?

Other than:
1) Vref Speeds
2) Flaps Man speed
3) Fuel situation
4) When to descend?

[autoflight]

A lot depends on when/where the double FMGS failure occurs on a small bus. Flying diagonally across the corner of a Jepp charts, outside radar coverage in a busy area with a frequency change was interesting. Immediate hand flying meant other pilot had hands full looking for onward chart corner, then manually tuning navaids. After that I got extra charts that they could be pre-folded at such diagonal chart corner crossings.