Minnesota Father and 3 sons missing in Wyoming.

[Ted]

The SE normally aspirated svc ceiling is irrelvant. 4000 to 7200, it's where the water table is. The slower glide down of a crippled twin is helpful, but usually not lifesaving (getting to pavement) as you have to get over a ridge usually to get to the runway. Landing out in the Rockies is usually unhospitable. What really counts is that if you have a twin in the Rockies, it better be a fire breathing twin loaded to SE svc ceilings of 14,000.

Many pilots, even of Seneca/340/414/421 types don't get that weight is critical. My full gross SE ceiling is 13,500 with the mods (Merlins). I have to be a shave below to make it over red table, and that is with an enroute failure. If I have a failure during climb, the question is can I turn and reintercept the inbound course.....(Eagle, and Aspen).

Well put from someone who knows his plane.

 

[Everskyward]

A canyon turn? Doesn't take that much, does it? I guess I was thinking that I would be starting at cruise speed, though cruise speed at 17,500 in the (normally aspirated) 182 was right around 80mph IAS IIRC, which is Vy at 10,000!

I don't know, you tell me. I've never had a normally aspirated airplane up to 17,500 that I can remember.

But, I think I still had enough energy for the canyon turn.

OK, I'm not the one who has tried the experiments. However keep in mind that you are, by your own calculations, at 80 knots. What's going to happen if you put down full flaps and enter a 45 degree bank? In a 2,000 FPM downdraft. In IMC. Keep in mind that it will take a while to decide to turn around, plus the fact that downdraft may not be smooth.

I was visualizing traveling westbound out of the Denver area with a headwind...

Hopefully you would realize that it wasn't a good day to try it well before you got to the point where you would think about executing a maneuver like that.

 

[Ted]

I don't know, you tell me. I've never had a normally aspirated airplane up to 17,500 that I can remember.

OK, I'm not the one who has tried the experiments. However keep in mind that you are, by your own calculations, at 80 knots. What's going to happen if you put down full flaps and enter a 45 degree bank? In a 2,000 FPM downdraft. In IMC. Keep in mind that it will take a while to decide to turn around, plus the fact that downdraft may not be smooth.

Hopefully you would realize that it wasn't a good day to try it well before you got to the point where you would think about executing a maneuver like that.

I'd agree on all points. While I've not flown in the Rockies in my naturally aspirated birds, I don't want to in IMC. As it is, at 15,000 ft the 310 was truing out around 168, with IAS around 130-135 KTS. While that doesn't sound that slow, my climb performance was about nil with a small layer of ice that the boots couldn't get off. I wouldn't have been able to keep up with much of a downdraft, and a 2000 fpm one would've had me going down. Of course, the ground was flat and 1000 MSL or below field elevations, so I also had a lot of altitude I could give up if needed.

I'd think that sounds like a bad idea all around.

 

[skidoo]

Not a snowballs chance in hell would I consider that move.
It might not terimanate in a CFIT but you would get on heck of a roller coaster ride and the groundspeed would make a grown man cry.

Just my opinion though..

I would rather be a live chicken then a DEAD duck...

Ben.

Ps... Funny you should mention those numbers because as I type this that condition exists right now.
snip...

I'm trying to understand others experience and thinking. I have relatively low time, but live near a lot of mountains too. In looking at that path, the valleys look to be near 8000 ft and the peaks and ridge-line up to 11000 ft. So, at most, there is a 3,000 ft difference. It looks like one could cruise just north of any up wind ridge virtually the whole crossing, say beginning just north of Bivouac peak and Reynolds peak. If you were at 16,500 you would still be 5,500 ft above the highest peak and almost twice the peak to valley. My experience so far says the higher I go, the smoother it gets. How high would you need get before considering crossing there? Or do you say NO regardless if winds are 50kts near the peaks from 310 degrees?

 

[bbchien]

So let me ask this of mountain flyers. say you are flying toward a mountain and encounter mountain wave, it is my understanding that you fly at an angle toward the rock so if you encounter the wave you can turn around quicker a turn of say 130 degrees vs 180. but what if you are flying over the mountain from the windward side then get slammed down by the wave. Ya can't turn back to the mountain so waddaya do?

Adam, the answer is "not get into that position".

I use 3,000 as my minimum clearance on a windy day, and more comonnly like 6,000. And if there's a rotor around, I fuggedaboud the whole trip.

Thanks to Ben for post #157. I nominate it for "best of string."
Ben I'll be out there on the 23rd.

 

[COFlyBoy]

I'm trying to understand others experience and thinking. I have relatively low time, but live near a lot of mountains too. In looking at that path, the valleys look to be near 8000 ft and the peaks and ridge-line up to 11000 ft. So, at most, there is a 3,000 ft difference. It looks like one could cruise just north of any up wind ridge virtually the whole crossing, say beginning just north of Bivouac peak and Reynolds peak. If you were at 16,500 you would still be 5,500 ft above the highest peak and almost twice the peak to valley. My experience so far says the higher I go, the smoother it gets. How high would you need get before considering crossing there? Or do you say NO regardless if winds are 50kts near the peaks from 310 degrees?

I think the answer is that there is no way to be sure that you will not get into conditions that exceed the climb capability of your AC. The rule-of-thumb I've been taught is for SE GA you don't go over the rocks if the winds are over 25kts. I will always follow that rule. Even at 16.5k you may encounter mountain wave (not the rotors) which could make the flight unpleasant.

Also most normally aspirated birds aren't going to make it to 16.5k. You also have to climb up there, which means going through the layer of very rough mechanical turbulence.

 

[denverpilot]

So let me ask this of mountain flyers. say you are flying toward a mountain and encounter mountain wave, it is my understanding that you fly at an angle toward the rock so if you encounter the wave you can turn around quicker a turn of say 130 degrees vs 180. but what if you are flying over the mountain from the windward side then get slammed down by the wave. Ya can't turn back to the mountain so waddaya do?

Don't fly at all when the winds aloft are high enough to create serious wave activity unless you can be a lot higher above the mountains than the MEA typically is. Seriously. Let the glider pilots out in the flat-land enjoy the wave, and stay out of the rocks.

Wave activity reaches up into the Flight Levels, easily... when it forms. You don't want to be up there in a light aircraft in it, at all. Strong lenticular clouds or even stacks of them, almost always form (but if there's no moisture, they won't... beware) on the Front Range from Pueblo to Cheyenne on big wave days. They indicate that it's a "no-go" day for Westbound in most GA aircraft out of Denver, for me. No thanks. Testing the structural integrity of the aircraft or just the attach point of my seat belts, isn't my idea of a fun day flying. Airline crews have to do it, and they regularly bounce FAs off the ceiling if they don't keep 'em in their seats and belted in, especially in winter when the Jet Stream comes further south.

Back to your question -- You're right... you've just described exactly why steep passes with well-defined crossing points are desired over passes that are long way up a high-terrain valley. You don't want high terrain that goes on forever on both sides.

If you have lots of lower terrain on the other side and get shoved down as you cross the pass, you can point toward the lee side if there's higher terrain there (typically south with our prevailing winds, but not always) that's pushing some of that wild air back up further out. And as Kent said, keeping the nose down and accelerating away sometime is the only option left. Having enough altitude to keep the nose down, is obviously, critical.

Besides being oriented to have massive rotor activity when the normal prevailing north-west/south-east winds aloft are blowing across it, Monarch Pass is notorious for this, as are some of the passes in the Black Canyon of the Gunnison area.

Monarch is where we find all the flat-landers who have had no mountain experience. On a VFR chart it looks very "do-able", while most of us go around it and use other passes in and out of the rocks in that area unless it's really calm out. Even then, you can still get rocked in Monarch Pass.

The passes that "usually work" and those that are "death traps" are very well covered in the Colorado Pilot's Association Mountain Flying courses. Highly recommended, if you're headed up into the rocks. Both the ground and flight portions.

 

[AdamZ]

Great info in this thread. Sounds like the high rock pilots stay put on windy days the way we here do when conditions are primed for ice.

Which leads me to another question. If you get your PPL in a place like Denver or Jackson Hole, Telluride or Montana does your PPL instruction automatically include a mountain flying course as a big part of the PPL or is it almost an aside sort of like the short time a PPL student spends under the hood just to give him or her a "taste"?

 

[gkainz]

not that I know of, I haven't heard or read about any primary student receiving any mountain flying exposure. However, there are a number of secondary training opportunities for Mountain Flying training here locally, including the annual one put on by Colorado Pilots Association.

 

[Everskyward]

Which leads me to another question. If you get your PPL in a place like Denver or Jackson Hole, Telluride or Montana does your PPL instruction automatically include a mountain flying course as a big part of the PPL or is it almost an aside sort of like the short time a PPL student spends under the hood just to give him or her a "taste"?

I think that depends on the exact location. Denver, contrary to what some people might think, is not IN the mountains. There are plenty of places for students to go on x-countries which would not involve mountains. However, if you got your private at Glenwood, Aspen, Eagle, Telluride, Jackson or Leadville it would be pretty unavoidable. I remember going up to South Lake Tahoe and some other places I can't recall in a C-150 from Oakland before my private checkride but that may be unusual. That flying club had recently had a mountain accident so they were very attuned to teaching people about the mountains.

 

[denverpilot]

Great info in this thread. Sounds like the high rock pilots stay put on windy days the way we here do when conditions are primed for ice.

Definitely. And most of us out here are woefully un-trained on how to know when clouds are "primed for ice", around here with our dry/high air, so we come out there and fall out of the sky in a big ice block.

(I'm lamenting that I missed way too many icing questions on the Instrument written this last Saturday. Grrr. Stratus, flat, IMC that's flyable around here is so darn rare... it's almost annoying... )

Which leads me to another question. If you get your PPL in a place like Denver or Jackson Hole, Telluride or Montana does your PPL instruction automatically include a mountain flying course as a big part of the PPL or is it almost an aside sort of like the short time a PPL student spends under the hood just to give him or her a "taste"?

Not common here in Denver. We try to discourage the new pilots from blasting off to the West for a while... it's not that far to just "go around" up toward Laramie via I-80 or down around the end run to KSAF if you're going a long way West.

North, South, and East aren't an issue... they're all mostly downhill.

Earlier X-Cs in the student's training are generally east... out to KLAA, KGLD, KSNY, KBFF, etc.

For the "taste" of mountains, a commonly used PP X-C late in the PP is from the KGXY area or a Denver airport to KCYS KLAR and back... asking the PP candidate if they want to come DIRECT back from KLAR, or ... hint hint... maybe back along I-80 until back over the ridge line and then southeast from there. (In a Skyhawk... or similar performance.)

Often-times, the wind at KCYS is blowing 15-20 out of the West, which might also be their first real taste of a steady but manageable wind ("Where do you put the controls for taxi?"), and it's almost always straight down the runway in KCYS, and it stays that way and gets stronger aloft, of course.

That "pass" crossing going over to KLAR is just slogging Westbound into a headwind for miles out of KCYS, going up as high as you like, because you have plenty of time (watch the fuel... another thing to discuss... "if your headwind is 40 knots"...), over the ridge line, then what feels to the student like a "slam dunk approach" into KLAR since you have a lot of altitude to lose to get there. (More good pre-takeoff/pre-flight fodder. "How fast do you need to come down after crossing this ridge to get down to pattern altitude, and where do you want to be at pattern altitude by?")

But that's about as "mountainous" as the PP-ASEL usually gets unless a student is just begging to head up into the rocks. Many instructors will just get them signed up to do mountain flying work immediately following the PP-ASEL if they're talking like they want to head up to the rocks. Many folks find it's just darn uncomfortable up there in a normally-aspirated single... it's bumpy, the climb rate can be downright annoying or alarming depending on what the wind is doing, and temperatures and Density Altitudes have to be watched like a hawk. (Perhaps, pun intended? - Hawks are the only birds I know who will flip you off on their way by the wing strut. LOL!)

Virtually every takeoff at mountain airports are already a virtual emergency procedure right from the start, with a predicted climb rate of 200-300 FPM in many light trainers, and your mind needs a bit of time to really absorb "regular" flat-land flying before trying to pile more in there between the ears.

Most mountain flying courses are at least a day of ground-school covering mountain weather, winds, typical courses and "safer" passes/crossings vs "the death-traps", and then a full day of flying.

CPA's normal "route" ramps up from one relatively easy pass crossing (Corona/Rollins Pass, just northwest of KBJC) into a relatively easy airport (K20V), then a chance to get a takeoff at high altitude and your first need to climb, but not super hard, to work down toward KEGE and 'round the bend into KGWS which now pits you with an "around a mountain for base to final turn" and a SHORT runway for the DAs seen in the summer.

Then a launch out of KGWS and "up valley" to KASE for a taste of our "high traffic" airport in the mountains,... up the valley, again around a mountain at an angle base to final (inbound traffic stays to the right, as does outbound traffic, and the runway is a one-way runway, so it's very common to have a light jet aimed right at you with all lights blazing as you turn final, and they'll be well above you and to your left before you get to the runway).

Then a launch out of KASE "down valley" (hug the right side, winds the day I did it wouldn't let me get over there that close to it, and even though I reported him "in sight" and KASE Tower also had us both in-sight, a Citation had to break off his approach VMC because he got a Traffic Resolution out of his black boxes. The tower sounded amazed when they said, "Where do you think you're going to circle?", obviously hinting that he was in a pretty deep valley, but he climbed up, circled around, and came back for the Visual again.

Meanwhile for me in the 182, this is the leg that has the really long climb... down valley until you can cross the ridge-line to the north, then a course-reversal straight east over Reudi Reservoir, and straight over that huge ridge straight ahead. You'll be in max climb all the way from the runway at KASE to about a 1/2 mile before the pass, in a 182. So this is the route ONLY if you're in something greater than 200 HP and you can go over Hagerman Pass to KLXV. If you can't you go all the way up to KEGE and work your way around and into a valley that leads down from there into the Leadville valley. Skyhawks and others go that way... and it's a LONG way around.

Anyway, you get your certificate for landing at the highest public-use airport in the U.S., and if you understand how airports need money, maybe buy a coffee mug, and some gas... at any of these airports along the way (even though it's expensive) just to help them out... but in my case... I couldn't afford the weight of the fuel since the temps were climbing to 70F and higher at KLXV. DA calculations and runway lengths were way off the top of the charts in my 1975 C-182P. You learn to extrapolate again... welcome back to 6th grade or so.

Then a north takeoff (usually) in KLXV since that's the typical prevailing wind, and an immediate turn down-valley to KSLT. It's not a required landing spot on the route, but some do. It was getting too hot to mess with it on my flight.

By the way... the down-valley from KLXV to KSLT is where the instructor's going to pull the power and let you see what an engine-out glide looks like at that Density Altitude... lots of places in that valley to pick for emergency landing spots, once you're headed south out of KLXV. But you're going to be surprised at how different the ground speeds are!

On my particular day, we did a partial simulation of this... it was too hot and the C-182s engine was feeling abused after the departure from KLXV... the cowl flaps had been open for hours at this point, and cylinder head temps were never where I really wanted them... there's very little cooling air moving through the cowl with the nose in the air at Vy or even Vx for a while, trying to cross a 13K ridge line...

Anyway... stayed in cruise config and let the poor airplane cool down, headed East past the Badger Mountain RCO southwest of Denver, and back into town. It's a workout. I was tired, sweaty, and had flown harder than I'd flown in years that day. And a new respect for hot/high and low performance.

So, no... it's not something most students going for the PP-ASEL get to experience, unless they specifically ask. They're just told to go do a proper mountain flying course prior to heading West out of any of the Denver airports.

Places like JAC... maybe they have no choice... since it's a little harder to get out of the "bowl" there?

 

[denverpilot]

Mountain winds today here... Think at 14K MSL these could overcome the performance of just about any aircraft?

http://bit.ly/epy2B7

Wheeee!

 

[flyingcheesehead]

OK, I'm not the one who has tried the experiments. However keep in mind that you are, by your own calculations, at 80 knots. What's going to happen if you put down full flaps and enter a 45 degree bank? In a 2,000 FPM downdraft. In IMC. Keep in mind that it will take a while to decide to turn around, plus the fact that downdraft may not be smooth.

In the 182, the flaps are slow enough that they might not even make it all the way down before the turn is complete - They help to create more lift and tighten the turn, and as soon as the turn is over I'd be selecting flaps up again. There should still be enough margin over the stall that the turn could be completed successfully with power on.

In a 2,000 FPM downdraft, you're going down whether you want to or not in a piston-powered bird. The idea is to minimize the turn radius and time so as to avoid the terrain and get out of the downdraft as quickly as possible. It certainly wouldn't be easy to do the turn in the downdraft with bumps, but by that point your survival depends on it.

Hopefully you would realize that it wasn't a good day to try it well before you got to the point where you would think about executing a maneuver like that.

Exactly! But I also know that I'm human and not immune from making mistakes - I have gotten myself into situations I didn't want to be in before, sometimes via my own mistake, sometimes via wildly incorrect weather forecasts, etc. So, I like to think through potential solutions to any situation, even the ones I don't want to ever get into, because when the time comes and you got into the situation anyway despite thinking you were immune by virtue of your decisionmaking skills, it's far to late to start thinking about solutions.

That, and the thought process and discussions that we have here can contribute to learning things that could be used in other situations.

Which leads me to another question. If you get your PPL in a place like Denver or Jackson Hole, Telluride or Montana does your PPL instruction automatically include a mountain flying course as a big part of the PPL or is it almost an aside sort of like the short time a PPL student spends under the hood just to give him or her a "taste"?

Sadly, the one time I got dual in the Denver area, the CFI had absolutely no mountain experience or training! I was asking him some pretty basic questions that he didn't know the answer to other than "we pretty much just stay east of that spot right there."

 

[ejensen]

Great info in this thread. Sounds like the high rock pilots stay put on windy days the way we here do when conditions are primed for ice.

Which leads me to another question. If you get your PPL in a place like Denver or Jackson Hole, Telluride or Montana does your PPL instruction automatically include a mountain flying course as a big part of the PPL or is it almost an aside sort of like the short time a PPL student spends under the hood just to give him or her a "taste"?

PP lessons on the Front Range don't necessarily include mountain training, mine didn't. DA of course, you deal with that from day 1, leaning and such. Most FBOs that rent require a mtn checkout before you can take the plane west. I'm sure lessons given in the mountains will include appropriate weather, wind, terrain awareness. And I talking about high altitude operations into paved airports. Back country operations with canyon flying, dirt strips are another subject altogether.

 

[Anthony]

Great info in this thread. Sounds like the high rock pilots stay put on windy days the way we here do when conditions are primed for ice.

Ahhh, yeah. Anything above 15 knots is too much for me and even then you get the updraft/downdraft issues. Did a lot of circles to clear the big stuff. fly light and go over the ridges at a 45 and you might survive. :wink2:

 

[denverpilot]

Sadly, the one time I got dual in the Denver area, the CFI had absolutely no mountain experience or training! I was asking him some pretty basic questions that he didn't know the answer to other than "we pretty much just stay east of that spot right there."

That's just sad.

 

[Everskyward]

In the 182, the flaps are slow enough that they might not even make it all the way down before the turn is complete - They help to create more lift and tighten the turn, and as soon as the turn is over I'd be selecting flaps up again. There should still be enough margin over the stall that the turn could be completed successfully with power on.

Why don't you just say that you would turn around? Messing with the flaps, first putting them down, then pulling them up, when the airplane is already in a precarious situation doesn't seem like a good idea.

 

[COFlyBoy]

Why don't you just say that you would turn around? Messing with the flaps, first putting them down, then pulling them up, when the airplane is already in a precarious situation doesn't seem like a good idea.

I agree Mari.

It seems like you'd want to do your turn at Vx. You are trying to keep the most altitude while traversing the least distance. Dropping any flaps will have a detrimental effect on your climb gradient. Remember that flaps don't increase lift. They increase drag and lift. In my bird, full flaps pretty much kills any climb.

I have been up over Rollins Pass and pretty much did a max climb from my home-drome up to the pass. As we were getting closer I was right at Vx and with the turbulence the stall light was flickering. Doing a "canyon turn" would have been nothing more than a 180.

 

[denverpilot]

I have been up over Rollins Pass and pretty much did a max climb from my home-drome up to the pass. As we were getting closer I was right at Vx and with the turbulence the stall light was flickering. Doing a "canyon turn" would have been nothing more than a 180.

Agreed. My Hagerman Pass crossing was at Vx and we had the minimum altitude necessary to attempt to cross only by the skin of my teeth... and a 200 FPM climb rate that was flopping from zero to 200, and we were watching it very carefully and the ridgeline to see if it was going up or down in the windscreen.

I can't decide what we're talking about though... at one point Kent was saying you needed a Turbo, but then went back to talking about his normally aspirated 182. At normal good weather temperatures up there, you're well above standard and the DA at a 13,000' ridge line is pushing the underside of the service ceiling on my aircraft, and above the service ceiling of a Skyhawk.

In the winter when the IFR stuff up there would generally start up, and the air is colder, the jet stream usually is far enough south that you can't find many days where the winds at the peak tops aren't below 15 - 25 knots, ever.

Pick your poison on that maximum speed... one person gave their maximum in MPH in the thread...

I'm going for 15-20 knots max, and know I'm probably getting rocked at 20, so bad that I don't really want to be up there. Doing that IMC sounds like a death wish.

 

[bbchien]

My favorite wintertime IFR in VMC trick (gotta have turbos) is to cross just above the cloud deck, which is typically topped at 20,000. When you have that layer below you, you can see any wave activity- it's like reading the surface of a white colored lake.

You can see where NOT to go, below you.

AS for strategy in the Canyon Turn, at 35% power you will not have sufficent power to maintain alittide in the Vx canyon turn. You have to be prepared to lose altitude to maintain Vx during the turn.....Many are not prepared for this. I've done it in the "big brother", the Cessna 205. It peels your eyeballs open.

 

[flyingcheesehead]

Why don't you just say that you would turn around? Messing with the flaps, first putting them down, then pulling them up, when the airplane is already in a precarious situation doesn't seem like a good idea.

We tested this both ways when I did the mountain flying course, and the flaps helped a LOT. Slapping the switch down as you roll into a 45º banked turn not only helps you maintain altitude without having to trim or add power (since you likely are already at full power in this scenario), it really helps the plane around the turn as well as helping you slow down to minimize the turn radius. I don't remember exactly how much the plane was slowing down, but the turn happens FAST and I'm pretty sure it was less than 10mph.

Now I'm getting tempted to go up and try this at 17,500... But I don't have oxygen.

I agree Mari.

It seems like you'd want to do your turn at Vx. You are trying to keep the most altitude while traversing the least distance. Dropping any flaps will have a detrimental effect on your climb gradient. Remember that flaps don't increase lift. They increase drag and lift. In my bird, full flaps pretty much kills any climb.

Hmmm. I think you would want Vy (or even faster) to get out of a downdraft. The rate of climb at Vx is lower than Vy, and you need to move forward as quickly as possible to get out of the descending air. Since we're talking about 2000fpm downdrafts, you won't be maintaining altitude at either speed, and after the turn is completed you should be pointing at descending terrain. So, you want the best rate because you'll both have a better climb (or actually, lower descent) rate, AND you'll be out of the downdraft sooner. Even Vy might not do it, depending on the relation between the downdraft rate and the climb rate and the surrounding terrain - You might even have to push the nose over so that you can speed up and get OUT of the downdraft as quickly as possible.

I can't decide what we're talking about though... at one point Kent was saying you needed a Turbo, but then went back to talking about his normally aspirated 182.

We've talked about an awful lot of things in this thread, for sure. I try, though, to quote what I'm replying to so that there's some sort of clue what I'm talking about.

 

[flyingcheesehead]

At normal good weather temperatures up there, you're well above standard and the DA at a 13,000' ridge line is pushing the underside of the service ceiling on my aircraft, and above the service ceiling of a Skyhawk.

Hmmm. Now you're gonna make me think. I was at Leadville one day, 9927 MSL with a DA of 12,200 (according to the AWOS). This was at maybe 6-7 PM. So, about a 2300-foot difference in DA. The following day, at maybe 2 PM I climbed up to 17,500 MSL and the DA (according to the G430) was 18,848 - About a 1350-foot difference, nearly 1000 less than the previous day lower down.

When the air is cold, the atmosphere shrinks vertically so even though your DA is low on the ground, as you climb your DA climbs faster than the airplane. So, on a hot day the atmosphere would expand and as the airplane climbed, DA would climb slower than the aircraft was climbing. Either way, you can't make an assumption about DA aloft from what the DA was on the ground. Of course, on a standard-atmosphere day (if such a thing existed - We'll just call it "close enough") the DA should climb at the same rate as the airplane.

The question becomes, is there ever a point high enough where the DA is higher on a cold day than a warm day? I think the answer would be "Yes". It's also probably WAY up in the flight levels. I would make a spreadsheet, but my head hurts already thinking about this one!

 

[N801BH]

Adam, the answer is "not get into that position".

I use 3,000 as my minimum clearance on a windy day, and more comonnly like 6,000. And if there's a rotor around, I fuggedaboud the whole trip.

Thanks to Ben for post #157. I nominate it for "best of string."
Ben I'll be out there on the 23rd.

Thanks sir......

look me up if ya got a little free time and maybe we can talk airplanes over some food.

307 690-7828.

 

[skidoo]

I think the answer is that there is no way to be sure that you will not get into conditions that exceed the climb capability of your AC. The rule-of-thumb I've been taught is for SE GA you don't go over the rocks if the winds are over 25kts. I will always follow that rule. Even at 16.5k you may encounter mountain wave (not the rotors) which could make the flight unpleasant.

Also most normally aspirated birds aren't going to make it to 16.5k. You also have to climb up there, which means going through the layer of very rough mechanical turbulence.

I must be missing something. If I stayed on the ground or just in the valley any time the winds above 10K ft were over 15-25 Kts, then I couldn't go anywhere. It seems to me they are almost always up there 20+ kts. Just the other day, I was flying the pattern and at 1000 ft, I was getting 35 kt winds, but near the surface upon landing, it was under 8 kts. It was actually a fairly smooth ride that day.

Now, I am not trying to downplay the risks and I do avoid going over peaks without being significantly higher than them, but it seems that there must be more information to consider.

Maybe I'm spoiled with a Turbo and just don't understand what it is like without it...

 

[Everskyward]

Maybe I'm spoiled with a Turbo and just don't understand what it is like without it...

So was I. What kind of airplane do you fly?

 

[skidoo]

So was I. What kind of airplane do you fly?

T182T. I have to be sure to push the nose over before reaching 12K so I don't need the O2. After doing so, it picks up speed quite nicely up there. If I just want to putt around slowly up there, I really have to reduce power to not climb more.

 

[Ted]

T182T. I have to be sure to push the nose over before reaching 12K so I don't need the O2. After doing so, it picks up speed quite nicely up there. If I just want to putt around slowly up there, I really have to reduce power to not climb more.

The only way my naturally aspirated Aztec is happy getting up to 12k is in the winter, an deven then frequently when I'm by myself. The 310 does better with the 300 hp 520s instead of the factory 470s, but you still notice.

Those extra 10" of manifold pressure make a big difference...

 

[Everskyward]

T182T. I have to be sure to push the nose over before reaching 12K so I don't need the O2. After doing so, it picks up speed quite nicely up there. If I just want to putt around slowly up there, I really have to reduce power to not climb more.

I always thought a Turbo 182 would make a great mountain airplane. I flew a Turbo 206 doing aerial survey and mapping for many years. It also would have no trouble at 12,000'. Still I can remember times when it felt like we were being tossed around like a small kite. It's been long enough ago, though, that I can't remember what kind of wind limit I used. Of course mapping photos are useless if they aren't relatively level so that played a part in it too.

 

[Everskyward]

Now I'm getting tempted to go up and try this at 17,500... But I don't have oxygen.

You don't need to go up to 17,500. Try it at 11,500 but only use enough power so that you are able to stay level then don't add any more during the turn. Granted the air is denser at 11,500 but that's as far as some airplanes are able to climb anyway. I was going to suggest wearing a hood since the premise is that you are in IMC but that would mean you would need to convince someone to go along with you.

 

[COFlyBoy]

I must be missing something. If I stayed on the ground or just in the valley any time the winds above 10K ft were over 15-25 Kts, then I couldn't go anywhere. It seems to me they are almost always up there 20+ kts. Just the other day, I was flying the pattern and at 1000 ft, I was getting 35 kt winds, but near the surface upon landing, it was under 8 kts. It was actually a fairly smooth ride that day.

Now, I am not trying to downplay the risks and I do avoid going over peaks without being significantly higher than them, but it seems that there must be more information to consider.

Maybe I'm spoiled with a Turbo and just don't understand what it is like without it...

Putting around in the pattern in a valley and climbing up over a high ridge are two very different things. Yes, I think there are places in the hills where it'd be OK to fly the pattern when winds are greater than 25kts. (not fun maybe, but doable) Colorado has some pretty darn big valleys in the Rockies that would be fun to fly even if you couldn't go over the ridges/passes.

Yes, I think your turbo has spoiled you. Those of us with NA planes can't just decide to go over the ridge. We have to fly passes which funnel the wind. A 25kt wind might actually be 50kts or more through the pass, which would not be a pleasant ride if you are only clearing the pass by 500 feet.

I shoot for 1000 feet above the pass, but for many CO passes that means you are still below the peaks/ridgeline.

 

[COFlyBoy]

Hmmm. I think you would want Vy (or even faster) to get out of a downdraft. The rate of climb at Vx is lower than Vy, and you need to move forward as quickly as possible to get out of the descending air. Since we're talking about 2000fpm downdrafts, you won't be maintaining altitude at either speed, and after the turn is completed you should be pointing at descending terrain. So, you want the best rate because you'll both have a better climb (or actually, lower descent) rate, AND you'll be out of the downdraft sooner. Even Vy might not do it, depending on the relation between the downdraft rate and the climb rate and the surrounding terrain - You might even have to push the nose over so that you can speed up and get OUT of the downdraft as quickly as possible.

My thought was that you want to keep the most altitude for the ground that you are travelling over. Vy will give you the highest climb rate, but it may not keep you the highest above the ground. I think deciding which to use would be based on info you just don't have in the cockpit, such as: what is the elevation gradient of the ground, how long will you be in the downdraft, etc. And then it probably takes a methematical model to determine which one will keep you the farthest above the ground.

 

[N801BH]

My thought was that you want to keep the , how long will you be in the downdraft, etc. .

That one statement is the key to survival.....
Once you cross the ridge on a very windy day there is NO going back for a do over.... You are committed and you hope the downdraft ends before the treetops and or rocks start......

Ben.

 

[flyingcheesehead]

You don't need to go up to 17,500. Try it at 11,500 but only use enough power so that you are able to stay level then don't add any more during the turn. Granted the air is denser at 11,500 but that's as far as some airplanes are able to climb anyway. I was going to suggest wearing a hood since the premise is that you are in IMC but that would mean you would need to convince someone to go along with you.

And that would make the climb take longer! But, it'd be an interesting exercise. Hey Pete...

I could reduce throttle to the level it was at full throttle at 18,848 DA:

Also, it looks like I did have a little more airspeed than I remembered, but 95mph IAS isn't much to write home about!

 

[denverpilot]

AS for strategy in the Canyon Turn, at 35% power you will not have sufficent power to maintain alittide in the Vx canyon turn. You have to be prepared to lose altitude to maintain Vx during the turn.....Many are not prepared for this. I've done it in the "big brother", the Cessna 205. It peels your eyeballs open.

It instantly puckers my butt in VMC if I make the call that I need to make a turn out, since performance is already so degraded and you're not super high above the terrain.

My shoulders have a tendency to head for my ears, and I have to consciously think about relaxing so I don't over-control in that turn. A solid karate chop to the area between my shoulders and neck by a CFI from the other seat really hurts when I do that. (Ha... ask me how I know. Sadistic instructor friend... back when I was "fighting" to learn landings long ago... never forgot it. "Relax, Nate." In my mental checklist for stressful cockpit situations, I have always had... "Relax shoulders" ever since then.)

I've always heard that the theory behind teaching chandelles in the Commercial syllabus is to teach you to make a max-performance turn while climbing, but they don't teach you chandelles where you must descend to maintain flying speed in the Commercial syllabus. Maybe they should. It'd save some lives. Doing a max-performance turn when there's performance left to spare is one thing... doing it when you're only just barely holding an altitude, is completely a different feeling in the gut.

Airplane still flies by the same rules, but your heart rate, blood pressure, and other physiological functions might give away your true feelings about having to do it, if you were being monitored.

It definitely gets your immediate and undivided attention, especially if you're already seeing any variations in airspeed due to turbulence!

 

[Kaye]

Most mountain flying courses are at least a day of ground-school covering mountain weather, winds, typical courses and "safer" passes/crossings vs "the death-traps", and then a full day of flying.....

Thanks for the great write up. I'll be out there in May looking for this kind of challenge before I head west to CA. Curious...what month did you do you course?

Kaye...another East Coast flatlander

 

[ejensen]

Thanks for the great write up. I'll be out there in May looking for this kind of challenge before I head west to CA. Curious...what month did you do you course?

Kaye...another East Coast flatlander

This year the scehdule for the Colorado Pilots Association is:
Saturday, June 18 and September 10, 2011, Mt. Evans Conference Room, Terminal Building, Rocky Mountain Metropolitan Airport (BJC), Broomfield, Colorado

http://coloradopilots.org/mtnfly_class.asp?menuID=47~47

 

[Clark1961]

I always thought a Turbo 182 would make a great mountain airplane.

The Piper equivalent of the Turbo 182 does make a pretty good mountain airplane (even before it became Frankenised). On departure from LXV we had 1,000 fpm with one light person in the pax seat and about 50 gallons on board. A 182 will get off the ground quicker and climb better but not by a lot.

 

[bbchien]

This is the actual GEYRS4 departure shot on Thrusday the 28th. There are Dragons in them there hills....bottoms at 7,500, tops at 9,000.

(Mislabeled Pic)

 

[denverpilot]

Nice photo!

 

[skidoo]

Don't you just want to get a bit closer?