A VDP will also not be published if the primary altimeter setting
comes from a remote source, if it is inside of the MAP, or if it is outside of a stepdown fix.
As one example, say you plan to fly at 4500 feet indicated altitude and the current altimeter setting
Pilots must ensure that the altimeter is set to the current altimeter setting
provided by ATC.
Pilots use the local altimeter setting
(based upon atmospheric pressure variation) for calibration prior to flight.
The SmartLanding system is a software upgrade to the enhanced ground-proximity warning system (EGPWS) that can provide warnings of an unstable approach, predicted long landing, inappropriate aircraft configuration, or incorrect altimeter setting
. Airlines can select the functionalities they want implemented.
Obviously the altitude that you're reading is a function of your altimeter setting
. If in class A airspace with 29.92 properly set, your true altitude might be off by a few hundred feet, but assuming you have an accurate local altimeter setting
, the altitude that you're reading should be pretty darn accurate, right?
You dial in TXK's altimeter setting
and prepare to brief the RNAV 5 approach again.
With your current autopilot, how many times have you been given a fresh altimeter setting
and had to rejigger the altitude hold so it matches?
It would not be at all uncommon to see a one-inch change in an altimeter setting
as one result.
The TAC hopped into the right seat and verified Shemya's 28.26 altimeter setting
. This barometric altimeter setting
yielded a 400-foot difference, with the radar altimeter in the uncomfortable direction.
The altimeter setting
was 30.14, so I set that in also.