748 / 744 NG FMC cosmetics

[Hardy Heinlin]

Good evening,

we know, on the legacy FMC the altitude constraint windows are displayed without a space:

12000A17000B


On the 767 Pegasus I just saw a space between the numbers:

12000A  17000B


Does anybody know whether the 748/744 NG FMC also inserts a space?

(The modifications just never end ...)


Thank you!

|-|ardy


(I wouldn't rely on the illustrations in the manuals; they don't always agree with the real screens.)

[emerydc8]

Hardy, check out this video. Where the AB FL and speed is involved there are no spaces, maybe because there is no room. But look at 00:35. There are spaces. Could it be that only where room is available there are spaces? The addition of FL might take up the space so there is no option to have spaces there.

https://www.youtube.com/watch?v=R8IlOOCWUNA&feature=youtu.be

Jon

[Hardy Heinlin]

You're right. And my random example above wasn't quite correct; what I really saw was this:

250/15000B_9000A

So it simply inserts the same amount of leading spaces for the second number as it does for a single number.

E.g. for a window between 90 and 50 feet it will insert 3 spaces before either number:

250/___90B___50A

I guess the legacy 744 FMC does the same. Just nobody ever saw such low numbers on the real deck.

The current PSX versions always display such windows in the most compact form:

250/90B50A

However, PSX does insert spaces for single numbers:

250/___90B


Regards,

|-|ardy

[emerydc8]

I'm sure 99% of the pilots couldn't tell you if there were spaces or not -- Stuff we look at every day but don't notice details like this.

[Hardy Heinlin]

Another cosmetic area:

The NG FMC has a new ATC LOGON page that allows more manual entries in fields that are otherwise propagated from other pages:

TAIL NO  <-- from FMC memory  Edit: in legacy FMC too
ORIGIN  <-- from RTE page
DESTINATION  <-- from RTE page

Does anyone know whether these fields are displayed in small font when they are not manually entered?

The airport entries propagate from the RTE page to the LOGON page, but not vice versa. So it might be nice to get some visual feedback by small/big font changes.


Regards,

|-|ardy

[Hardy Heinlin]

Regarding the new FIX INFO page:

The NG FMC allows pilot defined PBD and PBPB waypoint entries on the FIX INFO page in 1L. On the LEGS page such entries get a suffix with a sequence number, and the PROGRESS page in 4L always uses the suffix "00". I'm wondering what suffix the FIX INFO page uses. I guess it uses "00" as well.

E.g. VENUS180/55 will be displayed as VEN00 probably.

On the other hand, if you have entered 4 different PBDs of VENUS in the four FIX INFO pages, it would be nice if they were distinguishable on the ND. But the sequence numbers are reserved for the LEGS and shouldn't be used for off-route fixes. Perhaps they get letters?

VEN0A
VEN0B
VEN0C
VEN0D


Regards,

|-|ardy


Edit: I just learned how the suffix is designed on the 787 FMC. It's a dash and the page number, e.g. VEN-4. It's certainly the same on the 748 FMC.

[mark744]

Regarding the new FIX INFO page:
.......................................................


Edit: I just learned how the suffix is designed on the 787 FMC. It's a dash and the page number, e.g. VEN-4. It's certainly the same on the 748 FMC.

Same on the NGFMC 744
Rerards
Mark

[Hardy Heinlin]

Thanks!


|-|ardy

[Hardy Heinlin]

We know, for the landing flaps 25/30, the pilot or the NG FMC sets the flap related VREF plus wind-correction (which is entered on the APPROACH REF page at 5R).

Do you pilots (respectively does the NG FMC) add this wind-correction also to the other flap speeds, i.e.

VREF + 20 + wind corr
VREF + 40 + wind corr
VREF + 80 + wind corr
etc.
?

Is this airline specific?

Assuming no ATC intervention. How do you set the flap 20/10/5/1 speed bugs manually when you're not using the FMC? Do you add any wind correction there as well?



Regards,

|-|ardy

[emerydc8]

Do you pilots (respectively does the NG FMC) add this wind-correction also to the other flap speeds, i.e.

No. Not at any airline I've flown for. Unless you're landing at flaps 20 due to an abnormal, then you would make the additions.

[Hardy Heinlin]

Thank you.

[mark744]

We know, for the landing flaps 25/30, the pilot or the NG FMC sets the flap related VREF plus wind-correction (which is entered on the APPROACH REF page at 5R).

In our company, the wind corrected speed is not entered into the FMC.
The speed in the FMC is the one the FMC calculates based purely on pilot entered landing weight and desired flap
( unless the QRH instructs modifying the FMC speed and or flap setting  )

The wind corrected value is only set via the MCP 'bug'

Do any other companies put the wind corrected figure into the FMC?

Regards,
Mark

[Hardy Heinlin]

According to the information I have, the default wind correction in the NG FMC is 5 kt (displayed in small font). If you want to get zero, you need to enter "0" (big font).

I now understand that the FMC adds this value to the flap 25/30 speeds only.

The NG FMC uses the VREF + wind correction for performance predictions on the final approach leg. It doesn't make a big difference; just a few seconds and some drops of fuel. That's not even within the display range. For a continuous descent down to the FAF, the NG FMC expects the flap 20 speed at the FAF.

Theoretically, it could also be used for VNAV approaches when the MCP SPD window is still closed (before it automatically opens by the on-approach mode activation). When a flap point on the ND is passed and you set the respective next flaps with the flap lever, the NG FMC automatically sets the next flap related command speed. When you set flap 25 while the MCP SPD window is closed, I think the NG FMC will set the FMC command speed to flap 25 speed plus wind correction. I have to reread that part. Maybe this automation only works down to flap 20.


Regards,

|-|ardy

[mark744]

Yes, that's how I think it is too.

So the Vref dispalyed in the FMC is the Vref without any wind correction, and the +5 in small font is informing you that in VNAV (and speed window closed), the VNAV will use a target of +5 onto the Vref

That is, the Vref in the FMC does not include the +5

Mark

[Hardy Heinlin]

Exactly.

It would be interesting if the FMC were to add the value to the flap 20 speed already. This way it could be already integrated in the earlier flight phase before the MCP SPD window opens. If it's only applied during the time when the window is open, the speed bug will be manually set anyway. What remains is a tiny ETA/fuel adjustment on the last 4 miles. Really tiny. That's why I wondered whether the wind correction is already added to flap 20 speed etc.


|-|ardy

[Jeroen Hoppenbrouwers]

I think it may not really be the purpose of that feature to save a coffee cup of fuel. It is more likely that it reminds pilots in a nuanced way that there shall be a wind correction to the final approach speeds, and offers a spot where to put that. Fill in the complete landing form. Oh yes, wind correction.

And then it may help to get the speeds set up automagically on the MCP when you go intervention/override, one less possibility to forget the wind correction.

Hoppie

[Gilad]

Hey Hardy.

Any update on the due date of the NG FMC?

[Hardy Heinlin]

Hopefully this year.


|-|ardy

[Gilad]

Thanks!

[dhob]

Theoretically, it could also be used for VNAV approaches when the MCP SPD window is still closed (before it automatically opens by the on-approach mode activation).

This isn't accurate. The MCP window must always be manually opened when in VNAV, both for the Legacy FMC and NGFMC.
The NG FMC is "On Approach" when the flaps are out of up, which has two primary implications for VNAV.
The MCP altitude has no affect on VNAV PTH descent if MCP altitude is more than 300' from aircraft altitude, and;
If airplane is below VNAV PTH, and in approach logic, commands level flight in VNAV PTH until reaching the path.

The wind additive on the APPROACH REF page is only applied to the VERF entered, either Flaps 25, Flaps 30 or a NNC VREF (FLAPS DRIVE etc.)   

It is Boeing procedure to open the MCP speed window no later than the final approach segment, but that is for the Legacy FMC as well as the NGFMC. I don't believe they have reconsidered this for operators who are now all NGFMC. If the MCP speed window is left closed throughout the final segment, then an entered wind additive would make sense. However, for large wind additives, the final approach speed would be higher than FLAPS 20 speed. In this case the speed would slow to FLAPS 20 speed then accelerate to final approach speed when in landing configuration.