Dear Fellows Aviators,
I've had an interesting discussion with a colleague of mine regarding the use of VNAV in QFE. We fly in Russia, where approaches are conducted in reference to QFE. We use Collins FMS 6000 .
My understanding is that LNAV/VNAV approaches are not to be used in QFE,because the NAV database in most FMS is
referred to altitudes mean sea level (for obstacle clearance purpose). I might be wrong,so please correct me.
My colleague's opinion is that, we can manually change the altitude constrains in LEGS PAGE to match the height in QFE ,as long as we have set our altimeters to QFE.
I am attaching an approach plate at UUWW. Lets take a look at NDB rwy19 for example?
http://
If we set the approach on our FMS, it will show all altitude constrains in QNH by default i.e all altitudes such as those starting after point OSTIS would be shown as 2610',2280',1950' up to FAF and then 1410 as an MDA.
Now if we set QFE and manually change these altitudes in LEGS PAGE into height, such as 1976',1646',1316' up to FAF and then 776' as for MDA ,how will this affect our profile?
What are your thoughts on this?
I am getting confused on this , so any help explaining would be greatly appreciated.
Many thanks and Happy Holidays!
cskafan