Before I begin I have to admit that what Cary says about not going into the mountains when the wind up at the pass is greater than 20 knots is safer than what I'm about to promote. Flying only over the mountains would be safer. Staying out of the mountains altogether would be safest.

Reading "Mountain Flying" by Sparky Imeson was hard work but encouraging for me. I was a liberal arts major and struggled with the small amount of math and science required. Sparky actually knows that stuff. Mixed in with the math and science were some one liner experiencial jewels of wisdom, however. He, like I, believes a lot of clear weather fatalities were not caused by downdrafts slamming aircraft into the ground but rather by pilots trying to climb out of downdrafts.

Number one: Use terrain navigation and the controls, with jealousy saved zoom reserve, to maneuver the aircraft so as to be able to fly or glide to lower terrain at all times. Don't climb unless necessary to miss things.

Number two: When the air becomes fairly unstable, pitch up in updrafts and especially, for safety, pitch down to get through downdrafts as quickly as possible.

Number three: Don't pull back on the stick in turns, especially steep turns which may be absolutely necessary to turn to lower terrain. Allowing the nose to go down as designed guarantees a 1g turn, the safest turn at every angle of bank. High DA operations leave little zoom reserve in the form of airspeed. Don't waste it trying to climb when you can't climb efficiently. Wait for better air. This relaxation of elevator habit is most helpful in a crisis or upset.

The airplane will not stall. Only the pilot can do that and only by pulling back on the stick.

Now THAT made perfect sense to me. Maybe I'm starting to understand ContactFlying language after all...

Made sense to me too. The "liberal arts major" part through me for a loop though....

X-3

Now if we can get Contact to say “Rudder only turns” are appropriate in low ground effect with wings level, only when hooking a wing tip is a potential hazard. Otherwise, low “G” coordinated turns are “Good”. Skidding turns “Bad”.
(In my opinion)

Whether in the crop field or all the way down the runway, low ground effect dispels any thought of a coordinated level turn. This makes the much safer rudder turn or energy management turn necessary. This is good for the crop duster and any other pilot. Coordinated steep level turns near the ground are very dangerous.

Turning up to 180 degrees to acquire the target, from a start altitude of 200 feet or less, requires a steep bank and wind management (fall off downwind then turn into the wind in a P turn) allowing the nose go down to prevent load factor. Actually two energy management turns, shallow downwind for spacing and then back into the wind. Only with the nose down is a skid acceptable. Yes, coordinated is best. Whichever, the nose needs to be moving appropriate to the angle of bank. FAST. We can't safely look down at the ball when this low and pointed down. Use the rudder as necessary to keep the nose moving around swiftly. Getting a lot of the turn done early prevents having a wing down late in the turn and nearing terrain.

Two things cause us to seek zoom reserve, the extra energy over engine thrust that will just get us off and around or over things: weight and density altitude.

Zoom reserve can be found in the kinetic energy of airspeed, the gravity trust of altitude (think drainage as well as just being high), slope, ground effect, headwind, thermal, and the lift of wind over rising terrain.

There is a safety reserve in the POH gross weight. Alaska allowed bush plots to fly at 115 percent gross and crop duster pilots barrow some of this safety reserve by increasing load to find maximum for conditions. This extra weight causes the nose to be higher and airspeed to be slower. Descending turns are safer especially at this weight. Descending turns take advantage of the extra speed resulting from pitching down (gravity thrust.)

Density altitude causes the nose to be higher and the airspeed to be slower. Descending turns are safer especially at high density altitude. Descending turns take advantage of the extra speed resulting from pitching down (gravity thrust.)

Early in life I learned that sometimes things just suck!! As I was learning to fly, I noticed that on the really hot days that it sucked, the plane did not fly as well. On the nice cold non suck winter days the plane flew better. I read about all the traffic, airspace issues and crap the lower 48 pilots put up with and think that must suck! Sooo I gets to thinking someone did a study and found that flying in the country of Alaska is great and does not suck. So they just gave us a extra 15 percent. I do not like to take passengers or myself in the mountains when the wind is blowing but, knowing what side of the valley/pass to avoid does help. 30-35 mph just means you work harder. Altitude in a pass always feels better but it often puts you right into the worst stuff, unless you are way over the tops. So if I cannot go over the top I tend to stay very low. On a side note this is why that water bottle, purse, any other crap not secured will case big problems!!!! Don't leave loose stuff in the plane ever!
DENNY

I had been told that extra 15% was due to moisture absorbed by old wood and plywood aircraft and not applicable to my woodless rag and tube airplane......If I’m wrong...that would be an additional 292.5 pound moose quarter....that probably wouldn’t fit anyway!

During my 6K+ hours of flying air taxi in Southwest Alaska and AK Peninsula I just gladiatored up and fought the turbulence........until one day coming off Cape Newenham I scared the living sh#$ out of myself. I mean the magnitude was beyond my creative and twisted imagination. Since then I really don’t care for rough air, but it is a fact of life up here. I’m with DENNY in that I fly very low when it’s windy in the mountains as well as securing loose objects. It’s funny how a water bottle can end up from the top of the dash to behind the rudder pedals in no time.
I fly a 737 quite often in Southeast Alaska and in our stop in Wrangell it was quite blustery and a passenger commented how this area is probably the most turbulent we pilots encounter. I had to laugh. Yeah it’s bumpy but in my 17 years at the airline the worst rides I’ve ever consistently had we’re going into Palm Springs and Ontario California.
Did I mention I’m not a fan of turbulence.......

TVATIVAK71 wrote:...Yeah it’s bumpy but in my 17 years at the airline the worst rides I’ve ever consistently had we’re going into Palm Springs and Ontario California.
Did I mention I’m not a fan of turbulence.......

Your forgot about Tucson! I'm cruising along one day in the 185 at 14,500 feet. Doing 200+ ground speed on 29s in silky smooth air east of Tucson and watching a small Haboob below me. As I cross the mountains Tucson appears and I push the nose over to head down. Holy crap everything was in the air and I was getting bounced off the ceiling. A smart person would have just pitched up and climbed back into smooth air and landed somewhere else, like San Diego maybe. But no, "I was landing". How I didn't end up upside down I'll never know. Landed at Marana and the wind was still cranking and what did I see but another Wagon doing pattern work! Crazy!

I hate turbulence, and like Denny if I'm forced to fly in it it's near the ground, but I'd rather sit, have a cup of coffee, and let the world go by.

Mark Y,

I was a history major and BA rather than BS. Sorry about that. I was thinking about the more technically educated my sons and daughter in law were. Each started civilian work at twice my salary. We were prepared to send our sons to college. Greg, number one, said let the Army take care of that and enlisted.

Contact

DENNY said: "I do not like to take passengers or myself in the mountains when the wind is blowing but, knowing what side of the valley/pass to avoid does help. 30-35 mph just means you work harder. Altitude in a pass always feels better but it often puts you right into the worst stuff, unless you are way over the tops. So if I cannot go over the top I tend to stay very low."

I would like for y'all to expand on this nugget:

"what side of the valley/pass"; Is this determined by wind direction such as flying with the wind, against it, the wind is/not perpendicular to the ridge pass, etc? What am I watching for here?

How is being low in stiff wind conditions better than say 1000 to 1500'? Where is the "worst stuff" and how to avoid it? Way over is 2000' or better? How low is very low? And how is that low better than the altitude where the "worst" stuff is found?

Since I fly in hot and high mountains of New Mexico this would really be some helpful info for our flying. Thanks in advance!

DeltaRomeo,

Leverage and lift is on the side of the valley/pass where wind is forced over higher terrain. Like a sail tacking into the wind, some amount of angle is needed. More nearly perpendicular is not nearly as important as wind speed. Sorry about the bumps. We need to be close to receive the really good lift. Climbing up before we get close negates most of the really good lift. We have to both maneuver to remain close while always having an out to lower terrain. It is much like working the heading of a sailboat to get the most leverage. Going from the airport to the beginning of the valley/pass system, I stay low. I will fly slower only to take advantage of updrafts, but pitch down through downdrafts. I go from bottom to top, not trying to out climb terrain with my engine, but with God given wind energy.

Going before the wind, with some kind of tailwind, is the easiest. This is usually with prevailing westerly winds while heading easterly. With slow aircraft, we may be able to out climb terrain but two things are important. We still need to be able to maneuver to lower terrain if necessary. And we need to be close to the incline to receive good lift. Climbing up before we get close negates most of the really good lift.

Turbulence is wherever, but look at white water rapids. Turbulence is worse at the top of the wave and lee. The ride up is not as bad. I work a ridge, downwind of the valley, from where I am when I get there. I stay about 50 to 100 feet horizontally from the ridge. Since I'm staying in the same valley ridge system up to the pass, I don't cross any ridge. I follow the ridge up to the mountain downwind of the pass. I stay low in the pass or on the downwind mountain ridge in the rising air. Because the saddle, the pass, is a venturi, good lift will usually be found there and sometimes even downwind of the pass.

While there are no guarantees in an engine climb, there are also no guarantees in an orograraphic climb. It just makes use of all available energy. The down side is that relative heat is required to make wind. Usually bumps come with the relative heat.

Generally higher is better for turbulence because we are above irregular terrain. Generally, with smaller and low powered aircraft, higher cannot just be jumped into with engine power. Attempting Vy engine climb is generally very inefficient in the heat of day. Vx doesn't exist in the summer. Going west, high can be way too slow. Spending an hour to climb to 12,000 and into 60 mph winds up there, can defeat a 90 mph airplane with a 12 gallon tank.

Contact

The difference between getting up high as soon as possible and getting to the valley pass system as soon as possible is that the latter is more energy efficient. Time/fuel is saved by staying down in lighter winds longer and by using orograraphic lift more.

Think of the wind as water, if the wind is perpendicular to the valley coming from say your right side.

As it comes over the ridge into the valley you will have a downdraft. As it crosses the valley and hits the other side you can get a updraft effect. Wind speed and any terrain features will determine how turbulent it can be. A long smooth sloping mountain side tends to keep the air smooth to the bottom and across the valley, this may be a good place to fly if you don't need lift. A big vertical wall acts just like a waterfall with heavy downdraft a lot of very turbulent air at the bottom, that extends across the bottom.

Now look at the other side of the valley. The wind will be pushing up the side hopefully without a lot of turbulence. If you need lift this would be the place to be. However you can get some mixing and rough air from air rolling off the tops of the other side, big vertical wall on the leeward side could have some good lift but I would expect some rough air also.

The middle of the valley is a mixed bag, you can have big rollers coming off the top of the hills settling down in the middle, you may or may not find smooth air and if I do I expect it to change at some time because valley shape is seldom consistent. Move from side to side and find the best air. If you have to turn from the middle you usually have to climb for the turn keep that in mind.

How low is low. If I am going downhill or don't have to climb, I prefer below treetop level (rollin on the river). If no trees 15-20 feet. Thick real green trees are sometime all you have below you and you have to suck it up and get down on them. If I have to climb to make a pass, whatever it takes to get through is what I do. Depending on valley, wind, direction of travel I may hug a side and power through downdraft, or get use of updraft side to climb staying close to the wall. In general, I have found the higher you are the rougher it is. The severe updrafts and downdrafts will dissipate as they near the ground. The middle hight of the valley can sometimes be the worse place to be for turbulence.

So once you hit the pass where do you want to be?? Clouds usually determine how high you can go, that is why you did not go over a 2 grand above the mountains to begin with. If I know what is on the other side, I will stay low. If not, I like to get a few hundred feet AGL so I look through the pass and have vertical room for a energy management turn.

Mountain flying is like any other type of flying, The knowledge is in the books, and the experience has to be done by flying. Start slow go fly up, over, and around a range on a nice day. Then add a mild wind component, and see how it changes. keep progressing until you find you comfort limit, it usually grows with time.

Given todays training it seems wrong to slow down, pull one of flaps, and get low on the deck. But it beats getting the snot kicked out of you and the plane at 1,000 ft.

This is very general and by no means hard and fast rules that I follow. Every valley/range is different, every day the wind changes, so as usual the answer to most mountain/valley flying is, it depends. I don't fly for money and have stayed home or turned around as more times then I have gone into questionable winds/weather. So take my advice with a grain or shaker of salt as needed.
DENNY

More pontification.

I was up in the Copper River Vally last weekend and stoped by the Million Dollar bridge. They have a rough road strip cut in the trees above the bridge. It was blowing 20 or so down the river. There is a small ridge right upstream from the landing area that I expected could give us some trouble but the pilot before me said it was fine. Landing went well, and wife got to see the bridge so she was happy!! On takeoff I left it on the ground for a bit extra speed but it still did not want to climb, so had to do some pilot stuff and stay below the trees until I had some more airspeed. That hill was causing a smooth downdraft not a turbulent one as I expected. The other pilot later said he felt the same thing.

Wind straight up and down the valley is where you will want to stay in the middle, any small bump or side valley will cause the wind to roll and get turbulent. The pass will usually be smooth on one side and turbulent on the downwind side as you exit. usually related to how fast the downwind side opens.

In Alaska flying 20 feet AGL is not a big deal because be don't have a lot of wires, towers, windmills, or people think you have a problem because you are flying low. If you do fly low know your country so you don't find a power line or tram cable
DENNY

My only thought to add to all this discussion from pilots much better than I'll ever be is this: the older I get, the less I like turbulence! Or to be even more blunt, as ancient as I am, I HATE TURBULENCE!

But flying being what it is, I can still handle some turbulence pretty easily--but I still hate it!

And that has a lot to do with my 20 knot over the passes rule.

Cary

Diddo