Mode C Altitude Q - no Kalisman Correction? (Barometric Pressuredeviation correction?)

Steven P. McNicoll wrote:

If it's QNH everywhere there's no transition altitude.
....

Right.

As I understood, you said: This is the only way to set the altimeter. I
answered: No, there are a myriade of ways to do it, from which one was
chosen, probably for good reasons.

Maybe I misunderstood your first statement.

Stefan

"Stefan" wrote in message
...

Right.

As I understood, you said: This is the only way to set the altimeter. I
answered: No, there are a myriade of ways to do it, from which one was
chosen, probably for good reasons.

Maybe I misunderstood your first statement.


I was responding to Cockpit Colin's message on how things are done in New
Zealand. He said a correction for barometric pressure is applied only below
the transition altitude, and that there's no need for any correction for
flight levels. He assumed it's the same way in the US. I said it's the
same way everywhere, as the definitions of "transition altitude" and "flight
level" require it to be that way.

"Steven P. McNicoll" wrote in message
ink.net...

"Stefan" wrote in message
...

Right.

As I understood, you said: This is the only way to set the altimeter. I
answered: No, there are a myriade of ways to do it, from which one was
chosen, probably for good reasons.

Maybe I misunderstood your first statement.


I was responding to Cockpit Colin's message on how things are done in New
Zealand. He said a correction for barometric pressure is applied only
below the transition altitude, and that there's no need for any correction
for flight levels. He assumed it's the same way in the US. I said it's
the same way everywhere, as the definitions of "transition altitude" and
"flight level" require it to be that way.

For example in the UK, transition level tends to be 3000 ft except around
the major airports where it can be as high as 6000ft. This means that the
lowest FL is usually FL035.

The normal practice is to take off on the airfieldQNH, and then if on a
cross country trip, readjust the setting to the Regional QNH. This is the
lowest forecast QNH for the respective region.

On arrival at an airfield we set QFE which gives zero elevation when
landed.

Only IFR traffic is obliged to use flight levels above 3000ft or the
transition altitude (in fact one of the definitions of IFR is the use of
flight levels). VFR traffic can use then if they want but then should follow
Instrument flight Rules.

cb