Altimeter 3066

Correct. But you still are required to follow the NOTAM in extremely high
or low barometric pressure conditions. If you read FAR91.144 quoted he

"Sec. 91.144

Temporary restriction on flight operations during abnormally high barometric
pressure conditions.

(a) Special flight restrictions. When any information indicates that
barometric pressure on the route of flight currently exceeds or will exceed
31 inches of mercury, no person may operate an aircraft or initiate a flight
contrary to the requirements established by the Administrator and published
in a Notice to Airmen issued under this section.
(b) Waivers. The Administrator is authorized to waive any restriction issued
under paragraph (a) of this section to permit emergency supply, transport,
or medical services to be delivered to isolated communities, where the
operation can be conducted with an acceptable level of safety."

In other words, it says "Read the NOTAM" or "Get a Waiver". Normally the
NOTAM will restrict operation at certain altitudes so that safe altitude
separation can be maintained in spite of the inability to correctly enter
the barometric pressure.

John Severyn
@KLVK


"M" wrote in message
oups.com...
I don't believe VFR flight requires accurate altimeter adjustable for
barometric pressure. 91.205 only requires such altimeter for IFR
operations.


J. Severyn wrote:
"M" wrote in message
ps.com...

BTW, FAR 91.144 restricts flight operations when barometric pressure
exceeds 31 inch mercury. Any idea why? (note this restriction applies
to VFR traffic a well).


The Kollsman Window is only required to have a range of 28.00 to 31.00
inches Hg. So if barometric pressure is outside that range, you cannot
accurately set most altimeters.

John Severyn
@KLVK