Flying over mountains and weather

[nerf97]

how can a pilot really tell which way to go over mountainous areas given that at times you end up being in a violent turbulence. you are basically equipped only with knowing the leeward and windward sides. we know at times these are not enough. we need to "read" the area. sometimes with weather a choice or two.

What is really wise in reading the ranges?

[MBJ]

I try to imagine wind as a liquid flowing through and across the mountains - I find it makes it easier to imagine where the updraughts and downdrafts will be and where you are likely to get rotors.

I personally haven't ever heard of a structural failure to a helicopter due turbulence but I remember reading an article once about potentially overstressing helicopters because they feel as if they handle turbulence better than light aircraft.

I guess the answer is quit before you get frightened?

[birrddog]

A word of advice, although it may sound obvious....

Just because you are in a helicopter does not necessarily mean you need to scrape over the top of the mountain.... Give yourself plenty of altitude between the heli and the highest point, even it means going VFR on top (if allowed where you are flying).

Sometimes the turbulence is unavoidable even at high altitudes, though certainly always less the higher you fly over a mountain.

[Gordy]

For what its worth--if you understand the way weather, and more specifically how the wind reacts near mountains, it is no big deal to fly low over mountain tops.

I fly in mountainous terrain, (6,000 to 12,000), working fires for 9 months of the year. The best thing you can do is take some lessons in the mountains with someone who flies them on a regular basis.

Here is the best book that I have found for understanding weather. It is fire orientated but gives you a wealth of knowledge. I refer to it often. For understanding wind in the mountains---I would recommend chapter 6.

Go half way down the page to where it says Reference Material, and open the relevant chapter of the Fire Weather Handbook.

NWCG Fire Training (http://training.nwcg.gov/pre-courses/s390.htm)

[hoistop]

Here is my five cents worth,

I learned a lot about mountain winds and turbulence thru my 1200 hours of flying gliders cross country in the Alps - yes glider pilots do not fly when weather is bad, but does not matter much. I can tell you that you need to know a lot of fine details about air currents if you want to fly hundreds of kilometers thru the mountains without engine. May I suggest you get acquainted with glider pilots with mountain crosscountry experience-if you have a chance, try it (would reccomend high performance glassfiber glider, not some mediocre tin plane) It is great fun too!
Also, books on crosscountry soaring will tell a lot on this topic.
When flying into the mountains on a rescue mission as hoistop on a good thermal day, I sometimes feel terrible urgency to "redirect" my pilot when he is using raw power to climb instead of using a little bit of soaring techniques.:hmm:
Regards,
hoistop

[nerf97]

soaring techniques... i kinda tend to use "raw power" when Im on top mountains. that triggers me to look further into that. Thanks t'ya!