Historical low pressure-Dash-8s can’t fly

Today the barometric pressure in Norway is measured as low as 944 hPa/mbar! This has never happened before.

The regional airline Wideroe have grounded all Dash-8 100/200/300s.

My photo

Why? The altimeter will not give correct reading when the pressure is below 948 hPa/mbar, because the lowest setting they can adjust to in these aircrafts is 948.

Standard pressure is 1013 hPa/mbar(2992 hg)

When approaching an airport to land pilots get altimeter setting from ATC e.g. «Altimeter setting 2 9 9 2» So they can adjust the altimeter to the actual pressure and get correct reading from the instrument.

Hopefully we get some pressure soon so the small birds can fly again

34 Likes

That’s very interesting! I wonder why the pressure is that low🤔

2 Likes

My guess is the storm activity around Europe and the Atlantic

2 Likes

Also may cause some more minor problems for other aircraft since that runways going to feel something like 3,000 feet higher

1 Like

Here’s a chart I found that will give you guys some idea of what kind of performance hit they get (chart for a 737)

2 Likes

Here is a photo of the altimeter set to minimum 948 mbar/2800 hg

As you can see the altimeter shows 100 ft. The actual altitude at the location is 40 ft.

image

3 Likes

Looks like that’s roughly a 2,000 foot increase in pressure altitude. This chart I found only covers down to 28.0 inches, but 944 mb equates to 27.87 inches of mercury.


Source: Gleim Aviation

1 Like

Thanks for sharing.
Pressure altitude affects aircraft performance. These Dash-8s operate on short runways, steep approaches between mountains surrounded in fog so a working altimeter is critical.

1 Like

Never knew that aircraft could actually be grounded because of pressure. There was the very interesting discussion about special procedures with pressure above 1050hPa, but never heard of this. Really interesting!

The Dash-8 Q400 isn’t affected by this issue, right?

1 Like

Norwegian kid at recess:
Jumps
image

3 Likes

To be fair gravity and pressure are not entirely unrelated, but in that context gravity is what you want, pressure doesn’t let you jump to space…

scientist intensifies

I guess they’ll have to buy new altimeters for the fleet lol.

No, the Q400 is not affected

1 Like

That might be the case…

Thanks!

3 Likes

You guys are taking an L, quite literally.

Screenshot_20200211-095928_Chrome-01

2 Likes

Yeah lol. Today 21 Wideroe departures are cancelled in the northern part of Norway

3 Likes

What? I hope your kidding… 😂

1 Like

I’ll leave it up to you to decide if it’s fake news or not 😅

3 Likes

Has no one else done that? 😳


I stand brooms up all the time when I have to walk away from them for a second and there is nothing good to lean them on… 😂

2 Likes

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.