Aeronautical night in nordic countries

[oumpahpah]

Hello,

Happy to join PPRuNe ! I hope I will contribute to the community soon. For the moment I have the following question :

Does anybody know what is the legal definition of the aeronautical night in countries like Finland, Norway, Sweden ?

Is it the same as for instance France where it is SunSet +30' to SunRise -30' ? Or is there any other rule ?

Happy landings,
Bertrand, LFSP

[India Four Two]

Bertrand,

Welcome to PPRuNe.

Here is the definition for Canada from the AIP:

1.6.2 Morning and Evening Twilight Charts
In the morning, civil twilight begins when the centre of the sun’s disc is 6° below the horizon and is ascending, and ends at sunrise, approximately 25 min later. In the evening, civil twilight begins at sunset, and ends when the centre of the sun’s disc is 6° below the horizon and is descending, approximately 25 min later.

I expect the definition will be similar for the Nordic countries.

Following section 1.6.2 (GEN - 1.0 GENERAL INFORMATION - Transport Canada) there are two charts for determining the beginning and end of civil twilight.

In June at 60° N, "night" is less than two hours, and of course north of the Arctic Circle in June, there is no "night".

Winter is a different matter. A night rating is essential!

[M609]

From the Norwegian BSL-F (Rules of the air)

Night: The time the sun is more than 6 ° below the horizon

I.E even during the winter way up north, you can have the sun below the horizon, but still be legal VFR without a night rating.

(At my old location at ENDU/Bardufoss you have VFR day from 0918 local time to 1421 local time on january 1st, without ever seing the sun)

[oumpahpah]

Hello,

It's now aeronautical night here...

Regarding how to compute this data, is there anywhere I could look at or in ?
This in order, with Latitude, longitude and date, to calculate when the center of the sun is 6° below the horizon line.

Ughhh, what's about diffraction ? (no, no, that's a joke !)

Happy landings,
Bertrand

[Maoraigh1]

I remember a handheld GPS had it in its database.

[oumpahpah]

Hello,

OK. Thanks for the info.

However, since we are planning a trip to ENHV and making a lot of simulations, it would be more suitable to have it on a, for instance, excel sheet.

Happy landings,
Bertrand

[B4aeros]

From their respective AIPs:
Norway(pdf)
Sweden(pdf)
Finland

[thasle]

Twilight data for airports

Check out my web page Aviation - Links
You can retreive twilight times and sunrise/set for any airport in Europe.

Or go to this page for more detailed data: Sunrise, sunset, dawn and dusk times around the World - Gaisma

[Whopity]

All you need is an Air Almanac