Isavia ANS ehf., Reykjavíkurflugvelli, 102 Reykjavík /
Isavia ANS, Reykjavik Airport, IS-102 Reykjavik, Iceland
Sími / Telephone: + 354 424 4000 

AIC B 004 / 2021
Effective from  03 DEC 2021
Published on 03 DEC 2021

Flug í fjalllendi / Mountain flying
Content Responsibility: Icelandic Transport Authority

1 Information and recommendations

Mountain flying offers a unique view of Icelandic nature. Whether it is in the mountains, over a glacier or in valleys, it is often an unforgettable experience. But it is necessary to keep in mind that it carries more risk than flying over the lowlands. There have been incidents and accidents related to mountain flying.
For this reason, the Icelandic Transport Authority would like to present the following information and recommendations to pilots.

2 Weather

When flying close to mountains, special attention must be paid to the weather and winds.
It is important that pilots are familiar with the weather in the area to be flown in and are aware of wind direction and wind strength as it allows the pilot to estimate where turbulence and downdrafts can be expected. The greatest risk of turbulence and downdrafts is always on the downwind side of a mountain. The intensity of turbulence and downdrafts depends on wind speed.

It is a good idea not to fly below the height of mountain peaks on the downwind side of high mountains, so that turbulence can be avoided for the most part.
In the same way, it should be considered that weather conditions on the upwind side of mountains and ridges can lead to updrafts and turbulence.

3 Mountain waves

When a strong wind, over 15-20 knots, blows across mountains and mountain ridges, mountain waves can form in which up- and downdrafts can exceed 1,000 feet per minute. If an aircraft flies into such a downdraft, it can be difficult or even impossible to climb out of it.
It is a good rule of thumb not to fly lower than 2,000 feet above the highest obstacle. This minimum height should increase as the wind speed increases.

4 Situation awareness

Over the highlands it can be difficult to realize the exact location due to the lack of landmarks (roads, buildings, etc.). It is good to get to familiarize oneself with the route to be flown and be able to know the mountain ridges, peaks and valleys.
Good visibility is essential and it is important for pilots to be aware that visibility can deteriorate rapidly. There are examples of pilots falling into a deadlock over the highlands when visibility is impaired and they completely lose their sense of position.

5 In case of an emergency

Although the weather is good and warm in the lowlands, it can be cold and bad weather up in the highlands. In the event of an emergency where it is necessary to make an emergency landing in the highlands, it is important that the pilots are well equipped.
Regulations stipulate that when flying over areas where rescue could be difficult, equipment that ensures the safety of the crew and passengers for at least 24 hours must be carried in the event of an emergency landing, e.g. thermal blankets, protective clothing and emergency rations.
All aircraft must be equipped with an ELT that sends out an emergency message after a crash landing or manual activation. It must be ensured that the ELT is active after an emergency landing.

6 Contacts

The following may be contacted for information or to provide feedback:
     Icelandic Transport Authority
     Armula 2
     108 Reykjavik, Iceland
Netfang / Email:

Sími / Phone:  +354 480 6000


AIC hereby cancelled:  

NOTAM incorporated in this AIC: