737300737300
01-04-2002, 09:11 PM
I have found a bug in the Descent page of the FMC, and I would like to quote Chris Brady, to prove that the bug exists.
BEGIN QUOTE:
As you approach your ToD the FPA will remain at zero but the V/B and V/S
will both increase until the V/B is at about 3 to 4 degrees or whatever the
FMC has calculated is the optimum value. If VNAV (PATH) is engaged then the
aircraft will descend with an FPA equal to the V/B. The actual V/S will be
slightly different to the computed V/S because V/S changes during the
descent.
You don't need to use VNAV to see this because the FPA, V/B & V/S all
indicate at all times.
END QUOTE
In this message, he clearly states that The FPA, V/B, and V/S indicate at all times, and VNAV does not need to be engaged. This is incorrect in the DF737, where the V/B, and V/S only indicate during an active VNAV descent. Just thought i'd clear this up, and hopefully get a fix for this.
BEGIN QUOTE:
As you approach your ToD the FPA will remain at zero but the V/B and V/S
will both increase until the V/B is at about 3 to 4 degrees or whatever the
FMC has calculated is the optimum value. If VNAV (PATH) is engaged then the
aircraft will descend with an FPA equal to the V/B. The actual V/S will be
slightly different to the computed V/S because V/S changes during the
descent.
You don't need to use VNAV to see this because the FPA, V/B & V/S all
indicate at all times.
END QUOTE
In this message, he clearly states that The FPA, V/B, and V/S indicate at all times, and VNAV does not need to be engaged. This is incorrect in the DF737, where the V/B, and V/S only indicate during an active VNAV descent. Just thought i'd clear this up, and hopefully get a fix for this.