V Nav programming 767-300er

[Rob767]

how do you program the 767-300er FMC V Nav ?
this would be a great help

[Localiser Green]

Not a 767 driver but from several jumpseat rides on the 757/767 this is how I understand it to work:

For climb:

VNAV will use climb thrust and pitch to hold the ECON climb speed (based on cost index?) to the lower of: entered cruise altitude, MCP altitude. It will respect any speed restriction (like 250Kts/FL100) and this supersedes ECON speed.

For descent:

The FMC will calculate the T/D (Top of Descent) point based on the first altitude restriction on the way down. So if you have entered to be level at DAYNE @ FL70, it will calculate an idle descent profile from the cruise altitude to reach FL70 at that point. This is the most economic descent available.

In the descent itself, VNAV will command rate of descent down the calculated descent profile and apply thrust as required to maintain ECON speed (again with any entered restriction being respected).

Sorry to any 767 drivers if I have made a mistake here, this is just what I remember to be the case. Please feel free to correct / elaborate on my attempt!

[A/P Disc]

In general that's true. But the question was how to progam it.
V-Nav uses info from the Performance page which is loaded on
the ground. It requests info via dashes and boxes which have to
or may be filled. The FMC needs info like, ZFM, cruise alt, cost index,reserve fuel etc. It calculates the most economic climb speed for the loaded data.

In the legs page of the FMC you can enter restrictions. Like at the
first point during climb you want to be above 2000' whith a
max speed of 230 Kts. This would look like this on the legs page:

Dayne 230/2000A

Or for example Dayne 230/2000B

Which implies that a/c will level off at 2000' until you have
passed Dayne with a max speed of 230 Kts.

This speed/Alt data may be entered manually or may already
be in the database. Departures are in the database
under the dep/arr page.

This also goes for descent. You can enter a restriction as
mentioned by Localiser Green to be at Dayne at Fl70. It will
be entered like this on the legs page:

Dayne ..../070

Or if you want to be above Fl70:

Dayne ..../070A etc. You get the point.

As you see I left the speed in dots. Because of the cost index
which was loaded before the flight the FMC will calculate a
best econ des speed. Which would be something like .79/290 Kts.
( Just a rough figure). The FMC will, as already stated,
make a V-Nav path all the way back to you cruising level and
calculate the descent point to reach Dayne at this level.

Does this answer your question?

Rgds

[scanscanscan]

Nice present for Christmas reading.........
FMC user's Guide B757/B767/B747 FMC
From Mr Bullfer phone or fax 713/358-7252
Cost $45.00 in 1997

[A/P Disc]

Bloody good idea. Wish that I had thought of that. Would
have saved me a lot of typing.

Rgds

[Rob767]

thanx all
this is a great help
so u can still get the 767-300er FMC guide then?
thanx again:)

[spoilers yellow]

As a matter of interest, why are you so interesred in only a 767-300?

I see you have a few other posts on this subject and the questions seem slightly strange in their wording.:confused:

[Hippy]

I think I detect someone who has the 767 PIC add-on for Microsoft Flightsim and can't be bothered to RTFM.

If true, perhaps Rob could be persuaded to take his questions to www.avsim.com and use the 767 Pilot in Command Support Forum.