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Old 17th Oct 2012, 14:56
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Mountain winds

Question regarding mountain operations.

Todays forecast:
Moderate Turbulance below 15000,
winds at 500 and 1000 agl are 20-40 kts (forecast)
Terrain ranges are 10600 -12800,
Limited access to mountain passes at 8000 MSL
direct flights point a-b would be at >11500 MSL
Clear skies
This mornings temps range from -7 to 0 C
ACFT EC135P1
No PIREP

So in discussion with two other pilots whether I should be concerned about the turbulance and winds regarding flights into the back country the first states he has no issues flying into the back county being the RFM wind limits for the aircraft are for starting and shutdown.

The second says being Navy trained he is used to high winds and does not have reservations for the turbulance or forecast winds.

Am I being over conservative thinking not a day to be in the mountains?
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Old 17th Oct 2012, 15:09
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That is surely "your call" as PIC, to determine whether the task at hand is compatible with your skill levels and experience and relevant to your current needs and priorities.
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Old 17th Oct 2012, 17:39
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Sounds like turbulence due to surface friction, which you can usually mitigate by adapting your flight path.
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Old 17th Oct 2012, 21:06
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I'm not so experienced in mountain flying, but I had the chance to taste some.
Maybe you are new with mountains and it seems it's not clear to you what are the major dangers. What kind of job are you starting there?
Your approach is professional, checking the weather forecast before you accept the mission, but I would try to spend some time with experienced mountain pilots, instead of accepting risks you are not able to evaluate.
Provided you're flying a nice machine, I would not check the forecast to understand wether turbulences will be found there or not. In turbulence you just reduce power and speed and go back if it's too much.
Let you customer taste it in flight if he does not bellieve that it's better wait for tomorrow (but provide him with a plastic bag )
Many other aspects are more important.
Unwanted IMC kills much more than turbulence.
Performances should be checked expecting temperatures that are not changing exactly with the gradient you studied. Some degrees more than you expect could put you in troubles in the same place you have been flying and working yesterday.
I guess the working environment is similar to the alps. If you work on the stau side, the average (not all of them) winds will help you climbing. In the phon side you will find basically falling winds. Turbulences and winds are visible from the valley (cloud formation and winds moving snow from the top).
Beware of whiteout when you land on snow.
If your job is moving goods or people, start with the light ones (when you have more fuel) and end with the heavy ones)
You're flying VFR but keep an eye on your instruments. You don't have the usual natural horizon.
Don't trust people on the top when they tell you "Come in,weather is ok". Find it out by yourself.
Brief your passengers about approaching and leaving the helicopter when landed near slopes.
Forgive me for so much typing... Spend some time with experienced pilots.
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Old 17th Oct 2012, 23:54
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Are you in a teetering head machine? If so, you need a REALLY good reason to fly in moderate turbulence.

If in an AS350 or a BK117 or A109, fill your boots. But the passengers may also show you their breakfast.
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Old 18th Oct 2012, 01:28
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Should be no problem for EC-135, in a 206 it would be more interesting and no pleasure flight for sure. If its just A-B flight across mountain area and no mt.landings involved I don't see why not if the vis is good.
but operating and perhaps landing heavy in tight spots, maybe not
How big is the gust? Steady 40kts are better that 20kts with gusting 35-40
But in wind like this its good know your area well and try to read the terrain like a book and picture in your head where the CAT is and where you should not be flying and whether to over the tops or stay all way down in the valley bottoms
But I urge not go if you don't feel good about it.
your boss we be in the poo with you if the **** hits the fan.
stay on the upwind side

Last edited by rotorrookie; 18th Oct 2012 at 01:32.
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Old 18th Oct 2012, 11:08
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as usually said: if you have doubts ... ther is no doubt
If you have to work near the ground on windy days in the mountains, never trust forecasts ... you have to feelit at the right place.
Best luck and don't take any risk
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Old 18th Oct 2012, 14:54
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Thanks for the inputs, I'm just under 4000 hrs TT and around 300 of that is above 10000 in the Rockie Mountains in the UH-1. 700 hrs of twin time, 175 in the EC-135P1 this last year working a HEMS job.

I spoke to the three pilots that retired from this job. They had 20,23 and 25 years with the program and they reinforced what I already knew about the area and mountain ops.

Last winter I also had the pleasure of meeting a FW Instructor pilot that's been flying the area for 40 years. Some good stories and lessons' learned about the mountain passes we routinely fly.

The winds were from a low pressure area with a cold front, the plains east of the mountains had high wind warnings with gusts to 75kts.

The lead pilot has a "go and take a look" attitude and wants the pilots to adapt that for all flights.

His comments generated my thought processes or doubts to ask the question. Again thanks for the inputs.
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Old 18th Oct 2012, 15:04
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In the most extreme case 40kt translates to 4000'/min up or down-draughts - not something many helicopters can out climb at the best of times and although downdraughts don't keep going to the ground they get pretty close, and if you are in the wrong place it clearly presents some pretty extreme windshear such as in rotor turbulence. The chances of being able to stay on the upwind side A-B must be pretty slim, and it certainly it isn't going to be much fun in a teetering head!

If the gremlins in your stomach are saying no, listen to 'em!
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Old 18th Oct 2012, 18:05
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HEMS and "take a look attitude"

Havoc, I think the attitude of your chief pilot is not wrong.
Few years ago in the same base I'm on duty now, the crew were alerted for a mountain SAR mission. The captain decided that the weather was "no go", and did not accept the task.
The patient suffered neurological permanent damages.
One of the mountain rescuers, arrived on the spot by feet, had the good idea of stating that the weather was good.
This gave the start of a legal action of the patient family, today still going on. Even if the captain is the only person with the right to decide about it, the dispute is exactly about the decision and about the weather.
I'm pretty sure he did the right thing, but I'm also sure that if he took-off that day, no matter what the rescuer said, he could have show that on the way to the spot there was no visibility, even if on the top of that mountain the sun was shining.
When we are called for hospital transfers, that is another matter. Reaching the patient could be possible, but we need to be hundred percent sure that once we put it on board, we arrive at destination. When it is uncertain, we don't accept the mission, especially at night.
When we are called during daylight for what we call a "primary", we don't accept the mission only when just a take-off is dangerous. If we try, we take off informing the requesting unit that our arrival is subject to meteo conditions.
We "take a look" but of course we never enter IMC conditions or take a risk of unwanted IMC.
A different situation again when we are called for the islands. But this would be out of thread.
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Old 18th Oct 2012, 18:49
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Double edge sword, we complete a report for turn arounds i.e (unforecast)weather and are asked why did you go, what did you miss in your planning. Learning process sure......

Sounds like we have a similar process informing the requestor that there is the chance we cannot arrive. We also provide them options like another service on the opposite side of the mountians (204nm) They maybe an option if weather is an issue for us.

Last month we had a very similar weather pattern with a mountain request mid afternoon. We were already on a request, the towns in the area of the request reported later gusts >100mph in the valley.

Part of the equation also is the mass used for turbulence, I believe is 12,500lbs. For an EC135P1 forecast moderate might be severe.
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Old 19th Oct 2012, 01:43
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75kt gusts in mountain area is outside my comfort zone at least.
The "go take a look" is maybe not so bad way to run things, but we all have different point where we turn back and abort and that decision making should be respected but unfortunately that is not always the case.
Remember the AS-350 crash in Canada few years back, pilot decided to go out on a windy day and on final approach he was caught in some 3500-4000ft downdraft, never had a change..

Last edited by rotorrookie; 19th Oct 2012 at 01:45.
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Old 19th Oct 2012, 08:17
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I think that the most important thing is to know what YOU are comfortable with. So it is hard to make decision on what OTHER people are ok or not ok. Way too many factors in this as well; training, experience or lack there of, time in type, type of helicopter, mission, light conditions, local knowledge, weather reporting accuracy, ect.. the list goes on. Flights/conditions could be safe and acceptable to one individual, and very dangerous for another.

The important thing, which it seems like you are trying to do here is to always learn form any and every source you can. Know your limits and stick to them. How will you know your limits if you never experience for yourself nearing these limits. The trick is to figure out how to reach these and turn back/stop before surpassing them. If you can successfully do this, you will find that your limits will slowly increase, often then the limits of the machine or your body will be stopping point. This is the point where you can then learn and adapt a great deal from others, either their mistakes or their reaching the mechanical limits.

For myself, that forecast would have to be evaluated based on all of the things I mentioned earlier. If I was in a familiar aircraft in familiar terrain, I would not think twice. Although I also have extensive experience flying around mountains. This past summer found my limits at times and have had to say no, lets try it this way, other time just flat out "not in these conditions". It happens.

My most memorable and surprising even to myself, was successfully moving a drill with a long line in the mountains with 50 knot gusty winds. I remember telling the ground crew "we will try, but there is a very good probability that this will not be possible" & after we were done putting the drill back together "I can not believe we just did that".

So is my limit 50 knots or 60 knots. I would have to say that was at the limit of myself, now I know. This still does not mean that I would do the same for sure if it is 40 knots. EVERY TIME the situation needs to be re-evaluated.

Fly safe and keep improving!
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