Tromsø and other airports north Norway pressure too low to fly

LongRoadBob

LongRoadBob

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Air pressure at Tromso down to 945 mb, and wideroe and other airlines can’t set the kollsman window that low so grounded. Not sure it is the lowest, off the west coast and up north experiencing floods and record low pressure.

The news reported they can’t “land” when the altimeter is not set correctly, but you really don’t use altimeter for final, etc, so, is it just the approach descent that would be dangerous? Flight level should still work as all set to the same setting so...?? Anyway, no flights.
 
I don’t know European standards but here the altimeter needs to read +/- 75 feet of airport elevation for IFR flight.
 
945mB is 27.9"Hg. Many altimeters won't set below 28.1". This would be about a 200' error so no dice.
 
I believe this happens in Alaska fairly often, and one of the work arounds is to set the altimeter 1000 feet higher than the actual altitude, and place a warning sticker on the altimeter. Then all airports near the altitude you started from will be precisely 1000 feet wrong. The Alaskans can correct this, and give their work around.
 
Snowmass said:
You didn't specify IMC or VMC or is VFR not allowed regardless of the aircraft type?
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Most airlines aren't not allowed to operate VFR, or outside of any normal parameters in the manual. There were issues a couple of years ago in the desert Southwest of the US, when the temperature rose higher than the performance charts for some models of airliners caused flights to be cancelled. The airlines often need specific performance data to be legal, they aren't allowed to interpolate or work off the edge of the chart.
 
LongRoadBob said:
I’m not sure about VFR. But thinking since an altimeter is required it would have to functional?
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LRB. you are on the right track. An analogous situation happens here in the southwest when it is too hot to fly. Now the planes fly just fine when it is too hot, but the airlines don't have the proper charts to calculate takeoff and landing distances, making those operations illegal. I think your situation would and should be illegal for IFR operations as the pilots landing in low IFR could not see the runway until way late in the game, because the altimeter would not provide reliable guidance.

It seems to me that VFR operations should be allowed. But if that were allowed, "get there itis" might just have a lot of pilots descending on an IFR glideslope, and continuing beyond minimums because without reliable altimeter readings, they don't really have a good idea of where the minimums really are. -Skip
 
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