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flyer767

FMC Format for Altitude Ranges

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I cannot find the format to enter an altitude range in the FMC.

 

Specifically cross XXX intersection below 32000 and above 26000 at 280K.

 

Thanks

Don

 

 

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could not figure out a good search string.

 

Well good, and I know exactly what you mean.  When Ctrl+F fails, I go to FCOMv1 and look at the table of contents there, which covers both volumes. This usually gets me into the ballpark.  It helps to refer to the FCOM often because you'll start to remember what you're looking for looks like or about where it is at.

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I cannot find the format to enter an altitude range in the FMC.

 

Specifically cross XXX intersection below 32000 and above 26000 at 280K.

 

Thanks

Don

 

You can't make such an entry.  You can enter an altitude constraint as an "at", "at or above", or "at or below".  The only way to get a "windowed" constraint is to load a procedure from the FMC database.  A windowed altitude constraint cannot be entered manually.

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The only way to get a "windowed" constraint is to load a procedure from the FMC database. A windowed altitude constraint cannot be entered manually.

 

Actually Joe, the NGX version of FMS we are using does allow it.  The only trick is getting the order right, one works the other doesn't.  FCOM 11.31.21 bottom of page cites an example "220A240B."  I double checked since I have been occupied with other products and yes, I can enter a window constraint.  The NGX also allows be to enter something like 210B for speed too..., something the 777 will not allow.

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Actually Joe, the NGX version of FMS we are using does allow it.  The only trick is getting the order right, one works the other doesn't.  FCOM 11.31.21 bottom of page cites an example "220A240B."  I double checked since I have been occupied with other products and yes, I can enter a window constraint.  The NGX also allows be to enter something like 210B for speed too..., something the 777 will not allow.

 

Then it is incorrect behavior as the actual airplane does not allow it.

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The LevelD B767 also permits FMC/CDU pilot  "between altitude restrictions" entries. .. handy for ATC vectors / instructions.

For the PMDG 737 I took a look at the FCOMv2 page that Dan mentioned.

The FCOM page 11.31.21 does mention an Option for pilot entered speed/altitude restrictions modifications.


Does option mean some airlines have it and some do not?




From FCOMv2:

[Option – U10.7 and later]


When modified by the pilot:

“At or above” airspeed restrictions are entered with a suffix letter A
(example: 250A/).

“At or below” airspeed restrictions are entered with a suffix letter B
(example: 200B/).

Mandatory airspeed restrictions are entered without any suffix letter
(example: 220/).
At or above altitude restrictions are entered with a suffix letter A (example: 220A).
At or below altitude restrictions are entered with a suffix letter B (example: 240B).
Mandatory altitude restrictions are entered without any suffix letter (example: 270).

Altitude restrictions that are between two altitudes are displayed with the lower
limit first, followed by a suffix letter A, then the upper limit, followed by a suffix
letter B (example: 220A240B).

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The format works flawlessly as indicated in the FCOM. Thanks. I needed this for the SILCN4 arrival into KSJC. TROXX has a constraint of below FL320 and above FL260 at 280K.

 

For whatever reason the Navigraph data did not load properly into the FMC.

 

Don

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The format works flawlessly as indicated in the FCOM. Thanks. I needed this for the SILCN4 arrival into KSJC. TROXX has a constraint of below FL320 and above FL260 at 280K.

 

For whatever reason the Navigraph data did not load properly into the FMC.

 

Don

I took a quick look and Navigraph shows the STAR restriction at TROXX transition.

 

STAR SILCN4.12B FIX SILCN AT OR ABOVE 20000 SPEED 280 FIX VLLEY AT OR BELOW 19000 AT OR ABOVE 15000 SPEED 280 FIX BAXBE AT OR ABOVE 12000 FIX APLLE AT OR ABOVE 9000 SPEED 240 FIX GGUGL AT OR BELOW 8000 AT OR ABOVE 7000 FIX GAARY AT OR ABOVE 5800 FIX EDMND AT OR ABOVE 5600 FIX JESEN AT OR ABOVE 4100 FIX HITIR 4000 FIX OVERFLY ZORSA TRK 306 VECTORS

 

 

 TRANSITION TROXX FIX TROXX AT OR BELOW 32000 AT OR ABOVE 26000 SPEED 280

 

 

 

TROXX-res_zps6cxmbgwo.jpg

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I do not have an explanation for this. Improper loading of constraints has happened to me before and I just correct the constraint in the FMC.

 

Strange it loaded correctly for you and not me.

 

Don

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