New FMC for BA 744s?

[NWSRG]

G-CIVS has been doing some patterns around Scotland and Northern Ireland today and yesterday, as BAW9175. One suggestion is that a 747-8 FMC is being trialled for retrofit to the BA 744 fleet. I'm not sure as to the validity of this rumour, but maybe someone here can confirm or otherwise? Also, what benefits would this bring...can the existing 744 FMC manage RNAV for example?

[JammedStab]

RNAV navigation including RNAV approaches. Although I can't speak for BA 744 aircraft.

[Spooky 2]

Highly unlikely that the 747-8 FMC will make into a 747-400. The -8 FMC is filllled with problems at this hour and barely makes the grade for the -8, much less the -400. Very different platform behind the CDU.

[Ian W]

Perhaps think RNP rather than pRNAV. They are quite different in the procedure types that can be flown.

[Intruder]

The 744 can do RNP and P-RNAV. The only thing it MAY not be able to do is RNP 0.3 approaches.

The -8 FMC works fine for most things. VNAV is a bit flaky on the descent, and there are problems with some approaches with tight turns (e.g., MEX). The "barely makes the grade" description overplays the minor problems. Second software update is supposed to be available this week to address most of them.

I have heard previously that the -8 FMS was going to be available for the 400; don't know the cost.

[gas path]

The FMC's do not have the required amount of 'memory' for the aircraft route structure so they are being upgraded, together with FANS.
The other option would have been an absolute nightmare to manage namely an Eastern fleet and a Western fleet.

[Spooky 2]

Intruder I know your flying the -8, which I am not so you have the hands on advantage. Tell me does the -8 generate Vspeeds for T.O.? I ask this because I spent a few hours last week working on an alternative work around so the -8 instructors could do a demo for the FAA on a 747-8 course. I know that the Instructor cadre at Boeing have few if any good words to say about this FMC. Wonder what give there?

[Intruder]

Intruder I know your flying the -8, which I am not so you have the hands on advantage. Tell me does the -8 generate Vspeeds for T.O.? I ask this because I spent a few hours last week working on an alternative work around so the -8 instructors could do a demo for the FAA on a 747-8 course. I know that the Instructor cadre at Boeing have few if any good words to say about this FMC. Wonder what give there?
Yes, ours generate Vspeeds. The Aerodata performance upload can modify those Vspeeds, and we are having trouble with the uploads to the FMS, so we usually have to input them manually.

Dunno what problems they are having at Boeing...

[Intruder]

The 744 can do RNP and P-RNAV. The only thing it MAY not be able to do is RNP 0.3 approaches.
This is interesting and confusing to me (highlighted in my bold). Approach RNP 0.3 is a basic level of containment to be RNP capable.

Do you mean <0.3 RNP approaches?

...there are problems with some approaches with tight turns
Or do you mean containment issues on RF turns during 0.3 RNP approaches?
It may be a matter of company certification (OpSpec C384?), but we are certified to RNP1. We cannot do the RNAV approaches marked as "RNP 0.3" or "RNP 0.1" ("RNP SAAAR") in the 400. That's why I emphasized "MAY not"...

Example of the turn problem is the ILS DME-1 Rwy 23L into MMMX. The FMS will not make that last turn to final without significant overshoot, unless we manually intervene. I haven't flown it in the -8, but it's the topic of much company discussion.

[TopBunk]

ILS DME-1 Rwy 23L into MMMX

Never landed on 23 a MMMX, but I remember that there was a turn to finals issue onto 05L, even if fully configured (gear down flap 30) on the -400.

[William A Bong]

BA are using the -8 FMC. The GSS Chief Tech Pilot has been having quite a few conversations with them as to the "problems" that exist at the moment. As previously stated most of these are due to be fixed at some point.

[Spooky 2]

You gotta like that. "Most" of these are due to be fixed. Wonder what casued BA to switch over to this FMC when the Pegasus based FMC in the -400 works pretty good.:confused:

[B-HKD]

You gotta like that. "Most" of these are due to be fixed. Wonder what casued BA to switch over to this FMC when the Pegasus based FMC in the -400 works pretty good.

Spooky 2,

Already been answered by gas path:

The FMC's do not have the required amount of 'memory' for the aircraft route structure so they are being upgraded, together with FANS.
The other option would have been an absolute nightmare to manage namely an Eastern fleet and a Western fleet.

Thus, the change is happing because the 'Pegasus' is unable to store the current route structure. As gas path mentioned, separately grouping 52 -400s in two fleets would be problematic.

The -8 FMC has more memory and thus it is the perfect solution to the problem. And as Intruder has already said, the major firmware revision for the FMC is coming this week.

[JammedStab]

It may be a matter of company certification (OpSpec C384?), but we are certified to RNP1. We cannot do the RNAV approaches marked as "RNP 0.3" or "RNP 0.1" ("RNP SAAAR") in the 400. That's why I emphasized "MAY not"...



RNP 0.3 is approved. At least for some of them:ok: Then just manually enter the value.

[tdracer]

FYI, the 747-8 FMC was always intended to be retrofitable to the -400 (as others have noted, the -400 FMC, designed in the late 1980s, was simply out of capability).


The downward interchangeability apparently caused many of the problems they had with the FMC on the -8. Most of those issues have now been sorted out.