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-   -   Would You Fly Over the Sierras in an RV-12 ? (https://vansairforce.net/community/showthread.php?t=123041)

johnr9q 02-22-2015 03:25 PM

sounds like the biggest problem would be unanticipated downdrafts. Can these be predicted by keeping an eye on weather forecasts or can they occur in any weather? If you flew the RV-12 as high as it could fly would it be able to overcome these downdrafts? Sorry about the naive questions but I am not a pilot, just looking into an RV-12. I would fly the I80 corridor and there is an airport in Truckee and Blue Canyon. If I had engine failure would I be able to make these airports if I was flying at 12,000 feet?

Bill_H 02-22-2015 03:33 PM

I know a gentleman that has taken his RV12 above 16000 feet. Legally. With video and data proof. And it was still climbing. A few details.

An LSA has a regulatory ceiling of 10,000 MSL -- OR --- 2000 AGL. (CLARIFICATION - for Sport Pilot, see below)
So if you can find a good mountain, you can be up to 2000 feet above it legally.

He waited for good weather, took oxygen and a saturation meter.

Achieved 16207 feet and was still climbing. was less than gross weight.
Has all the Density altitude/true altitude flight logs and calcs.

Time to climb SL to 10,000 ft was 14 minutes.
10 - 12 K was 5 min.
12-16 K was 24 minutes.
15 to 16 K was 8 minutes.
He feels that 17500 was achievable but could have taken another 20 minutes at less than Vy.

viper139 02-22-2015 04:29 PM

Quote:

Originally Posted by grubbat (Post 961531)
I wouldn't mind seeing a pic of the area you guys are referring to. All we got here in the southeast is pine trees, cell towers, and pine trees.

These will give you an idea of what they are talking about. I live at the base of the Sierra Mountains and they should be respected but the scenery is unparalleled.

https://www.google.com/search?q=sier...K&ved=0CB8QsAQ

Ron RV8 02-22-2015 04:59 PM

VFR in the mountains...Worth what you paid for it
 
I learned to fly in the late '60s in the Fraser Valley near Vancouver BC. Although there were mountains all around us, most flying was over the flood plain. I never really learned to navigate because I always knew where I was just by looking outside. Although I had intended to go commercial, life got in the way and I went on to do other things...

Fast forward 20 years and my new wife was silly enough to re-kindle my interest in aviation. After a bit of re-training, a typical mission profile involved flying a rental 172 from the interior of British Columbia to the Pacific coast. This involved crossing the Coast Range, with numerous 8,000'+ rocks sticking up. In good weather it was a breeze, 10,500 ft direct, not a problem. As often happens on the west coast, ceilings were often lower, which meant flying the passes.

On a couple of occasions while flying the passes on a windy day, we encountered some pretty good turbulence (enough to tip us up on one wing), and some interesting sink that we managed to fly through before it got dangerous. Hmmm, maybe I need to know more. Who best to learn from??

It just happens that there is a large glider club situated on the West side of the Coast Range at Hope BC. Now those guys deliberately go and play around the big rocks on a windy day, in fact they pray for wind. The light bulb lit up..

Lessons were available so I told them what I was trying to learn and over about 5 lessons learned a lot about lift, sink and turbulence in the mountains. Heck my wife even took a few lessons and enjoyed it immensely. The objective was to learn, not to get a glider licence, although that was tempting.

Just to show that some of the glider tricks might be useful to us power guys, here's a little story of our last glider lesson trip.

We took off early morning from Penticton BC in a C172 with 4 souls on board. Our rate of climb was about 200' / min and it took us roughly 30 miles to get enough altitude to climb out of the valleys. Pretty normal for a 172.

We were lucky enough to arrive in Hope BC with a reasonable wind from the west. Too long ago to remember how much. My glider lesson included S turns in a mountain bowl with climb rates in excess of 1000 fpm.

At the end of the day we all climbed back into the 172 for the trip home. Hmmm, the bowl was empty of gliders. I took the 172 into the bowl, did 3 S turns climbing at 1800 fpm and was headed home...

A few things I learned:
- wind doesn't strictly blow up one side of a mountain and down the other. It forms waves like a rock in a river. If you're in sink, move over a few hundred feet and you'll probably find lift...
- keep a sense of wind direction at mountain top level. You can do this by watching your drift. Stay away from the lee side.
- if the wind at mountain top level is greater than 20 kts, it can be nasty if you're close..
- glaciers create sink downslope
- check out Sparky Imeson's books, though some of them will scare you...http://www.mountainflying.com/
- take a mountain flying course
- if "mountain wave" is forecast in the big rocks, think seriously before you launch!
- some people prefer to follow roads. In many cases you can cut corners.

Almost everywhere we go is in the mountains. Be careful and have fun learning...

I would not hesitate to take an RV-12, a Piper J3 or anything else into the mountains. Just learn the capabilities of yourself and the airplane and fly within them.

Black Tusk near Whistler BC...


alexe 02-22-2015 05:19 PM

Mike S.,

Would you feel safer or less at risk in a Cessna 172? I think there has been a few of those that have crossed the Sierra chain successfully in the recent past :-)

If I recall correctly, the performance numbers for the -12 are equal to or better than a 172, icluding its rate of climb and service cieling.

Alex

Ron RV8 02-22-2015 05:46 PM

To better answer your questions
 
Quote:

Originally Posted by johnr9q (Post 961550)
sounds like the biggest problem would be unanticipated downdrafts. Can these be predicted by keeping an eye on weather forecasts or can they occur in any weather?

Quote:

Originally Posted by johnr9q (Post 961550)

If you flew the RV-12 as high as it could fly would it be able to overcome these downdrafts?


Sorry about the naive questions but I am not a pilot, just looking into an RV-12. I would fly the I80 corridor and there is an airport in Truckee and Blue Canyon. If I had engine failure would I be able to make these airports if I was flying at 12,000 feet?



Downdrafts are usually related to strong winds, sinking air below a glacer etc. There is a reason for them. Learning to fly and taking a mountain course will answer these questions...

There are downdrafts created by mountain wave that very few aircraft can outclimb, unless you're flying something like an F16... When you learn about them you will know to stay on the ground when they are forecast... Mountain waves occur because of very high winds aloft. Investigating this would be part of your pre-flight planning.

Regarding your route, I just looked this up on the map... Keep in mind I have never having flown this route...

On a calm day, this looks like it could be flown at any altitude you are comfortable with, from 1000' over the highway on up. Heck it looks like there's pavement (potential runway) all the way...

On a moderately windy day I would like to be at least 2000' above the mountain tops... You can still follow the road...

On a day when mountain wave was forecast, I would stay home and have a beer so as not to second guess my decision...

You might want to consider taking a couple of flying / gliding lessons in a mountainous area, and getting your instructor to explain some of the mysteries... Another option might be to hook up with one of the RVers in your area and do some exploring. Check out a local EAA chapter... That might help with your comfort level...

Good luck with your quest...

rvbuilder2002 02-22-2015 05:50 PM

Quote:

Originally Posted by Bill_H (Post 961553)
An LSA has a regulatory ceiling of 10,000 MSL -- OR --- 2000 AGL.
So if you can find a good mountain, you can be up to 2000 feet above it legally.

Correction.... A pilot flying under a Sport Pilots license is regulated by these limits.
If a light sport aircraft is being piloted by an private pilot, he can go to 17,999 (as long as he meets the oxygen requirements).

rockwoodrv9 02-22-2015 05:56 PM

Many of the airports in Colorado start out higher than the passes in the Sierra's. I have never flown in an RV-12 but considered it real hard before deciding on the 9A. I have flown out of Aspen, Rifle, and Glenwood Springs in the 9A with no issues.

I would be real interested in stories from guys flying into and out of the high altitude airports in the 12. I am happy with my choice, but still like the 12!

Gisnar 02-22-2015 06:19 PM

No reason not to go if weather is OK, and you respect the mountains.
Local instructor that give mountain flying courses is Bill Schroeder. CFII, flight examiner and a great guy.
David
Carson City, NV

RFSchaller 02-22-2015 06:49 PM

I don't like flying routes that don't allow a Plan B in any airplane. I used to fly my Cherokee between Phoenix and San Diego monthly for my Navy Reserve weekend. Most of the time I ended up flying that 40 mile stretch of mountains east of San Diego in the dark. It was always with the knowledge that a forced landing was probably going to result in the loss of the plane and a high probability of serious injury or death. I didn't dwell on it, but it was always in the back of my mind. After retiring from the reserves I never flew that route again at night.


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