Re: 7x7-EFIS question

Date:         31 Dec 99 02:09:31 
From:         "John Vincent Lombardi" <>
Organization: UniPhone MP
References:   1
Next article
View raw article
  or MIME structure

In article <airliners.1999.1255@ohare.Chicago.COM> , ice <>

> How well does the 757/767 conform to the ideal descent profile with
> VNAV engaged with strong tail winds? I have heard FLCH is a better
> tool in such circumstances?

Well, garbage in, garbage out. If the forecast winds in the descent are
accurate, and have been entered in the box, the descent profile will be
right on.  If, on the other hand, the top of descent winds aren't
representative of those encountered in the descent and no descent forecast
winds have been entered, some speed or drag corrections might need to be

Using FLCH in the descent will provide a constant speed, thrust idle descent
without regard to any vertical navigation restraints. The two modes are
complementary, but only VNAV will provide descent planning with calculated
top of descent point and crossing restrictions taken into account.

> Also do you HDG SEL onto the LOC, or LNAV? I assume because of
> Map Shift you HDG SEL..

Most often, HDG SEL is used to join the LOC because that phase of flight
usually entails radar vectors. LNAV can be used to join as well. LNAV is
sometimes used when the join up is fairly far out on finals. Flying inbound
on the LNAV LOC course is much smoother with less hunting. The important
thing to remember is to transition to LOC before reaching MDA ;-).

Hope this helps,


John Vincent Lombardi     
San Francisco, CA