terry

On Apr 18, 9:05 am, Bertie the Bunyip <A...@AA.AA> wrote:
> terry <tfm...@iprimus.com.au> wrote in news:375462b0-66e7-4ed0-b45d-
> e6e089f79...@s50g2000hsb..com:
>
>
>
>
>
>
>
> > On Apr 18, 7:10�am, Stefan <stefan@mus._INVALID_.ch> wrote:
> >> 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.
>
> > As I understand it ( In Australia) the QNH in an ARFOR must be within
> > 5 mbar of the "real QNH"  - ie what gives you field elevation for any
> > place within that area. otherwise the area will be broken up into sub
> > areas and no 2 adjacant sub areas must differ by more than 5 mbar.
> > That way the errors which Wing flap alludes to, and must certainly
> > exist in non ISA atmosphere, would result in errors of no more than
> > 150 feet between aircraft using either the correct AFROR QNH or the
> > airfield set QNH
>
> Yipes! Are you studying to be an astronaut?
>
Are there any openings?