Altimeter Question

WingFlaps wrote in news:4a79e95a-8313-4834-a217-
:

On Apr 18, 5:36*am, Bertie the Bunyip wrote:
WingFlaps wrote in news:fdf0b97d-aac6-4ac1-
a936-
:







On Apr 18, 3:58*am, Stefan wrote:
WingFlaps schrieb:

That's a good question as Eurocontrol recognises QNH as the
correct
local barometric setting (they also state that it means Query:
Newlyn
harbour). I thought the ICAO agreed with Eurocontrol on these
things?

Actually, it's the other way round: Eurocontrol adheres to the
ICAO
phraseology.

*From The ICAO Manual of Radiotelephony (ICAO Document 9432)

Glossary:
QNH: Altimeter sub-scale setting to obtain elevation when on the
ground

Example:
Fastair 345, descend to 4000 feet, QNH 1005, transition level 50,
expect
ILS approach runway 24

WTF are the Americans doing not using ICAO standards or is it just
Gig601 being wrong?

Mostly just that it evolved into what it is and there would be a lot
of
resistance to change. For one thing it would mean changine every
altimiter in the US for ones who's Kollsman windows were in mb ( or
Hpa
if you prefer) It would also mean a complete revamp of airspace,
though
there has been some moves towards international harmonisation there
in
the last 15 years or so. Likewise with ATC, there has been some
movement
towards harmonisation. I think it's a case of softly softly catchy
monkey in regards the FAA's approach. Introducing too much "furrin"
stuff all at once would raise an outcry and probably dash any chance
of
harmonisation completely. Imagine, if you will, Jay hineck whining
about
lefties form Europe making him change his altimeter on his
"Pathfinder"
Whatever the **** that is, and you will see what I mean.


In the spirit of reciprocation, I can tell you that Pathfinders
dropped flares on targets for bombers during WW2.


I doubt they were fleets of Cherokees guided by playstations, somehow.


Bertie

On Apr 18, 5:51*am, Bertie the Bunyip wrote:
WingFlaps wrote in news:4a79e95a-8313-4834-a217-
:







On Apr 18, 5:36*am, Bertie the Bunyip wrote:
WingFlaps wrote in news:fdf0b97d-aac6-4ac1-
a936-
:

On Apr 18, 3:58*am, Stefan wrote:
WingFlaps schrieb:

That's a good question as Eurocontrol recognises QNH as the
correct
local barometric setting (they also state that it means Query:
Newlyn
harbour). I thought the ICAO agreed with Eurocontrol on these
things?

Actually, it's the other way round: Eurocontrol adheres to the
ICAO
phraseology.

*From The ICAO Manual of Radiotelephony (ICAO Document 9432)

Glossary:
QNH: Altimeter sub-scale setting to obtain elevation when on the
ground

Example:
Fastair 345, descend to 4000 feet, QNH 1005, transition level 50,
expect
ILS approach runway 24

WTF are the Americans doing not using ICAO standards or is it just
Gig601 being wrong?

Mostly just that it evolved into what it is and there would be a lot
of
resistance to change. For one thing it would mean changine every
altimiter in the US for ones who's Kollsman windows were in mb ( or
Hpa
if you prefer) It would also mean a complete revamp of airspace,
though
there has been some moves towards international harmonisation there
in
the last 15 years or so. Likewise with ATC, there has been some
movement
towards harmonisation. I think it's a case of softly softly catchy
monkey in regards the FAA's approach. Introducing too much "furrin"
stuff all at once would raise an outcry and probably dash any chance
of
harmonisation completely. Imagine, if you will, Jay hineck whining
about
lefties form Europe making him change his altimeter on his
"Pathfinder"
Whatever the **** that is, and you will see what I mean.

In the spirit of reciprocation, I can tell you that Pathfinders
dropped flares on targets for bombers *during WW2.

I doubt they were fleets of Cherokees guided by playstations, somehow.



Now that would have surpised the German's! Would they be painted
black? I'm sure not having the nav and beacon lights on at night is
just SOP.

Cheers

I learned to fly in France in the 1980s and they used a weird
combination of feet and meters. Altimeters read in feet,and minimum
safe altitudes were charted in feet. But charted obstructions and
airspace restrictions were in meters. Everyone set QFE (altimeter
reads zero on the ground) for takeoff, then reset the altimeter to QNH
if leaving the traffic pattern. Flight levels began at 3500 feet.

Can any Europeans out there tell me if it's still like that?

I fly in Eurpoe a lot an dmercifully tht doesn't seem to be the case,
but having said that, I only use insturment charts in France...

Does the ATIS give both QNH and QFE? I flew mainly from an airport with a
tower and no ATIS. If you told ground you were staying in the pattern they
gave you just the QFE, otherwise they gave both. And the VFR airport charts
gave the difference between QNH and QFE (in hPa) for each airport, along
with the field elevation in both meters and feet.

WingFlaps wrote:
On Apr 18, 3:58 am, Stefan wrote:
WingFlaps schrieb:

That's a good question as Eurocontrol recognises QNH as the correct
local barometric setting (they also state that it means Query: Newlyn
harbour). I thought the ICAO agreed with Eurocontrol on these things?
Actually, it's the other way round: Eurocontrol adheres to the ICAO
phraseology.

From The ICAO Manual of Radiotelephony (ICAO Document 9432)

Glossary:
QNH: Altimeter sub-scale setting to obtain elevation when on the ground

Example:
Fastair 345, descend to 4000 feet, QNH 1005, transition level 50, expect
ILS approach runway 24

WTF are the Americans doing not using ICAO standards or is it just
Gig601 being wrong?

Cheers




Call this number 870-862-3090 AWOS for KELD.

"Barry" wrote in
:

I learned to fly in France in the 1980s and they used a weird
combination of feet and meters. Altimeters read in feet,and minimum
safe altitudes were charted in feet. But charted obstructions and
airspace restrictions were in meters. Everyone set QFE (altimeter
reads zero on the ground) for takeoff, then reset the altimeter to
QNH if leaving the traffic pattern. Flight levels began at 3500
feet.

Can any Europeans out there tell me if it's still like that?

I fly in Eurpoe a lot an dmercifully tht doesn't seem to be the case,
but having said that, I only use insturment charts in France...

Does the ATIS give both QNH and QFE? I flew mainly from an airport
with a tower and no ATIS. If you told ground you were staying in the
pattern they gave you just the QFE, otherwise they gave both. And the
VFR airport charts gave the difference between QNH and QFE (in hPa)
for each airport, along with the field elevation in both meters and
feet.




Now you mention it, some plaes in France do also include the QFE.

Bertie

WingFlaps schrieb:

So an altimeter set to local QNH will always read field elevation *by
definition*.

Yes it may say that but it's being loose because it forgt to include
the "barometric pressure reduced to MSL by application of the ISA".
Alltimeters are calibrated for the standard atmosphere. -right?

Right.

Think about it, if an ARFOR gives QNH how could it be correct for all
terrain if local temperatures differed? I covered this in my PPL tech
course -was this not covered in your manuals?

Think about it, nobody said it would be correct for all altitudes, but
just for one altitude: the airfield elevation.

just in case you still don't see it, from Wiki:

Wiki, the ultimate authoritative source.

Hint: Look up the difference between QNH and QFF.

On Apr 18, 7:55*am, Stefan wrote:
WingFlaps schrieb:

So an altimeter set to local QNH will always read field elevation *by
definition*.
Yes it may say that but it's being loose because it forgt to include
the "barometric pressure reduced to MSL by application of the ISA".
Alltimeters are calibrated for the standard atmosphere. -right?

Right.

Think about it, if an ARFOR gives QNH how could it be correct for all
terrain if local temperatures differed? *I covered this in my PPL tech
course -was this not covered in your manuals?

Think about it, nobody said it would be correct for all altitudes, but
just for one altitude: the airfield elevation.



Perhap we are at crossed purposes but an ARFOR does not refer to an
airfield -that's a METAR and not all fields issue them. So in this
case how can QNH give field elevation unless it's an ISA day?

Cheers

Cheers

Cheers

On Apr 18, 3:33*am, "Barry" wrote:
Actually, there are a lot of anomolies around the world. Eastern Europe
and Russia doggedly cling to using windspeed in Meters/second and have
reluctantly accepted using feet for altitude, though there are still a
lot of published platform altitudes of something like "2746 feet"

I learned to fly in France in the 1980s and they used a weird combination of
feet and meters. *Altimeters read in feet,and minimum safe altitudes were
charted in feet. *But charted obstructions and airspace restrictions were in
meters. *Everyone set QFE (altimeter reads zero on the ground) for takeoff,
then reset the altimeter to QNH if leaving the traffic pattern. *Flight levels
began at 3500 feet.

Can any Europeans out there tell me if it's still like that?


Its still like that in australia, we use feet for altitude , but we
use meters for horizontal distance. OurVFR rules are to stay clear of
cloud by 1000 feet vertically and 1500 m horizontally. Hpa for
pressure except tire pressure which is psi

WingFlaps schrieb:

Perhap we are at crossed purposes but an ARFOR does not refer to an
airfield -that's a METAR and not all fields issue them. So in this
case how can QNH give field elevation unless it's an ISA day?

Again: QNH gives *by definition* the field elevation. If an ARFOR gives
you a QNH, then it is related to one well defined spot on the surface.

No doubt about it, a high pressure system has moved in, therefore a and c are correct.

Rich Anderson
TGH Aviation

Originally Posted by terry

I am confused by this practice commercial nav question. ( at least I
am confused by the answer in the book which was b. but I think both a
and c are correct), but I appreciate some other opinions.

Day 1 Altimeter reads elevation of 1390 feet with 1013 HPa set on
subscale
( thats equivalent to 29.92 inches of Hg for the US folks)
Day 2 Altimeter reads elevation of 1000 feet
Assuming the altimeter subscale was not changed between day 1 and day
2 it could be said that

a. The QNH is higher on day 2
b. The QNH is lower on day 2
c. The pressure altitude at the airport is lower on day 2
d. The atmospheric pressure at the aerodrome has not changed.

Terry
PPL Downunder