Mountain Flight Planning

[gismo]

Bingo! That os where I was flight planning towards. If the weather is good I'll head south a little more til my minimums come into play.

7V6 (Camp Gurnsey) used to be one of my favorite fuel stops near RAP but I haven't been there in a couple years and I heard it went way downhill, service wise.

 

[bbchien]

Go here: http://forums.aopa.org/showthread.php?p=964184#post964184 and look a the post with the sectional that includes togweetee pass.

It's not possible to approach that one at 45 degrees to the ridge. It's a funnel on BOTH SIDES. Thus, the need to learn the DETAIL DETAIL DETAIL approach to mountain flying.

 

[LearDriver]

Scottsbluff, NE always makes for a good stop as well. There is also Sidney, NE. The home of Cabelas. Thats right next to I-80.

 

[jesse]

BTW, my favorite posts in these mountain flying threads are the "mine's bigger" posts where people get huffity and say things like:

Did you calculate your ceiling on a cold day or a warm day?

As if that kind of knowledge makes you qualified to fly in the mountains.... (hence my distrust of mountain flying courses).

I'm a flat-land guy--explain to me--how knowing your airplanes ceiling throughout different temperature ranges is worthless knowledge?

 

[gkainz]

Scottsbluff, NE always makes for a good stop as well. There is also Sidney, NE. The home of Cabelas. Thats right next to I-80.

Ditto on Sydney - plan on half a day or better to even scratch the surface of Cabela's. When you call in on CTAF, have the FBO request the Cabela's shuttle for a free ride over and back. There's a couple decent motels in town.

 

[Anthony]

Ditto on Sydney - plan on half a day or better to even scratch the surface of Cabela's. When you call in on CTAF, have the FBO request the Cabela's shuttle for a free ride over and back. There's a couple decent motels in town.

Yep. Greg, remember when we flew up there in the Tiger. We drooled over a lot of the stuff in the "premium" gun room. Man I wanted to get a real Colt SAA. Ahhhh, someday.

Cabelas runs a van over to Sidney. IIRC the FBO calls them for you if you ask.

 

[flyingcheesehead]

Kent. That is a beautiful photo. What airport is that?

Johnson Creek, 3U2 IIRC, one of the best-known backcountry strips in Idaho. There's a fly-in of Super Cubs there every year. REALLY cool place. Pretty hard to get there via anything other than an airplane, and they're really well set up for camping on the field. There are bathrooms, hot showers, a creek that runs nearby, and plenty of hiking and climbing to be had. A little piece of heaven.

The Colorado Bureau of Aviation produces a nice map that features the location of mountain passes, lists the mountan AWOS freequencies and other useful info. Combined with a Sectional its a very good tool. I'll see if I can find a link to it.

Here ya go:

http://www.colorado-aeronautics.org/aeroform.cfm

Cool - One "problem" with flying the Idaho backcountry is that people are making their position reports based on things that aren't on the sectional - The place I did the mountain flying course recommends picking up USFS maps to get to know the various mountains, passes, whatever that people use for position reporting. (Everyone's on 122.9 there, it's the CTAF at all of the backcountry strips and is also used for position reporting going up and down the valleys.)

 

[SkyHog]

I'm a flat-land guy--explain to me--how knowing your airplanes ceiling throughout different temperature ranges is worthless knowledge?

I can't, and that's my point. Everyone knows what they need to know already, or they're deficient as a basic, VFR pilot...

 

[flyingcheesehead]

Multi:

thanks for the info, but I wasn't asking your airplane, but Geico's.

Well, it looked like you were asking about mine, since you were quoting my post.

Of course in a C182 with a service ceiling of 18K you have
more options.

Yup.

 

[flyingcheesehead]

Mountain Flying Courses are really only useful for people lacking the basic knowledge of flying that was originally taught during primary instruction

Nick, seriously. How would you know what is taught in a mountain flying course if you've never taken one?

I have, and there was a LOT of stuff in there that isn't covered in primary training. I had never heard anything about mountain flying except "take a mountain flying course" and I didn't really know what to expect.

I flew through mountains on the way to get to the mountain flying course and didn't kill myself, just as you have flown through mountains and not killed yourself either. I could have taken your head-in-the-sand, "I know what I need to know" approach, but I really did learn a lot from the course, and had WAY more fun than should be legal.

I advise you go here http://www.mountaincanyonflying.com/ and take their course. You WILL learn, and you will have fun.

 

[SkyHog]

Nick, seriously. How would you know what is taught in a mountain flying course if you've never taken one?

I have, and there was a LOT of stuff in there that isn't covered in primary training. I had never heard anything about mountain flying except "take a mountain flying course" and I didn't really know what to expect.

I flew through mountains on the way to get to the mountain flying course and didn't kill myself, just as you have flown through mountains and not killed yourself either. I could have taken your head-in-the-sand, "I know what I need to know" approach, but I really did learn a lot from the course, and had WAY more fun than should be legal.

I advise you go here http://www.mountaincanyonflying.com/ and take their course. You WILL learn, and you will have fun.

My primary training was a mountain flying course that lasted over a year. I fly out of a high elevation airport, and all of our training was done through (relatively benign) passes and over mountainous terrain.

I know what they cover because I know what's needed to be known.

You haven't given any specifics on anything other than "experience" that you gained from the mountain flying course....no one does. If you can give me one thing you learned that primary instruction didn't (or shouldn't) teach....well, then I'll admit some value.

 

[Anthony]

Everyone knows what they need to know already, or they're deficient as a basic, VFR pilot...

Your airplane doesn't know if its over big mountains or at sea level terrain at any altitude. I get that. However, winds, updraft, downdrafts, weather, are all different in big mountains. Most GA pilots fly, if weather permits, at optimum altitudes around 7,000 - 8,000 ft. or lower over "normal terrain". The don't need to get up over 12,000 - 14,000 ft very much, take off at very high DA airports or navigate through mountains and over inhospitable terrain. Yes, the concepts and skills needed to do this successfully are in primary training, but are optimized by specific instruction in mountain flying.

 

[Everskyward]

I have a lot of time in the mountains of Colorado in small, albeit turbocharged, airplanes and most of what I learned was OTJ, observation or self-taught. All I have to say is you need to have a lot of respect for the mountains and don't let yourself get into a position where you have no outs. I had to learn to plan my escape routes when doing low level mapping in inhospitable terrain.

You can fly a small non-turbo airplane in the mountains but the conditions need to be good. If you fly better equipment, you can fly in somewhat worse conditions, they key word being "somewhat". You need to know your limitations, though. I can tell you that I have, at times, felt like a small kite in a fairly big airplane.

 

[flyingcheesehead]

I know what they cover because I know what's needed to be known.

Uh, those are two completely different things. You know some stuff, but you don't know what they cover until you take the course, even if you knew what they were going to teach you before you took the course.

You haven't given any specifics on anything other than "experience" that you gained from the mountain flying course....no one does. If you can give me one thing you learned that primary instruction didn't (or shouldn't) teach....well, then I'll admit some value.

Okay, Mr. Smartypants know-it-all mountain pilot , pop quiz time:

1) Winds are calm. Which side of a mountain/ridge will have updrafts, and which will have downdrafts? Bonus question: How far from the mountain will these updrafts be felt?

2) You camp overnight at a backcountry airstrip in a canyon (say, Johnson Creek above), and you want to fly out to breakfast in the morning. Which way should you expect the wind to be blowing in the morning when you take off? How about in the evening when you fly back in to have a cookout at your campsite?

3) You're flying an Archer (180hp) from a strip at a DA of 8,000 feet. What is your approximate available horsepower?

3a) Maximum gross weight on your Archer is 2550 pounds. How much weight must you remove from the cabin to achieve book performance at 8,000 feet DA?

3b) Your Archer can climb 1,000 fpm at sea level at max gross. What will be your rate of climb at 10,000 feet DA?

4) You encounter a downdraft and you begin descending at full power and Vy. What should you do?

5) You're flying an airplane through a canyon at 110 knots. You realize you can't make it out of the canyon. You roll into a 45-degree-bank turn. Will you be able to complete the turn successfully? What speed *should* you fly through the canyon?

I'll post my answers after you either attempt to answer them, or admit that there is knowledge to be had from a mountain flying course.

I'm sure your primary training was better than most in regards to high-DA flying, because you were doing it. Most flatlander primary training consists of (in the voice of Mr. Mackey, the school counselor in South Park) "Density altitude's bad, mmmmkay?" However, none of the above knowledge is on the PTS, and as someone who has repeatedly complained about the "difficulty" of the private pilot checkride, I'm surprised that you think it should be added.

 

[gkainz]

Yep. Greg, remember when we flew up there in the Tiger. We drooled over a lot of the stuff in the "premium" gun room. Man I wanted to get a real Colt SAA. Ahhhh, someday.

Cabelas runs a van over to Sidney. IIRC the FBO calls them for you if you ask.

well worth the trip ... Cabela's never gets old to me.

 

[SkyHog]

Well, I'll give it the old college try, using common sense and knowledge gained elsewhere (except for 2 of the questions, which don't need specific answers)

1) Winds are calm. Which side of a mountain/ridge will have updrafts, and which will have downdrafts? Bonus question: How far from the mountain will these updrafts be felt?

I'm going to assume the answer lies in heat. The sun will rise in the east and set in the west, so in the morning, with calm wind, you'll have updrafts on the east side of the mountain, and vice versa in the evening. The distance? As far away as you can feel? I don't know that one.

2) You camp overnight at a backcountry airstrip in a canyon (say, Johnson Creek above), and you want to fly out to breakfast in the morning. Which way should you expect the wind to be blowing in the morning when you take off? How about in the evening when you fly back in to have a cookout at your campsite?

This is one of the questions that doesn't need an answer, as you can observe the winds before you takeoff/land.

3) You're flying an Archer (180hp) from a strip at a DA of 8,000 feet. What is your approximate available horsepower?

I'd need the book to answer this, but the answer will be "considerably less" than the horsepower at sea level.

3a) Maximum gross weight on your Archer is 2550 pounds. How much weight must you remove from the cabin to achieve book performance at 8,000 feet DA?

Again, I'd need the book to answer definitely, but I would assume the answer lies somewhere near "It can't be done."

3b) Your Archer can climb 1,000 fpm at sea level at max gross. What will be your rate of climb at 10,000 feet DA?

I'd need the book to answer that question. Considerably less, probably around 300fpm, would be my guess, and I may be overstating that.

4) You encounter a downdraft and you begin descending at full power and Vy. What should you do?

Ahh, here we go. You turn away. You were smart enough to not approach that ridge at 90 degrees, right? You'll have plenty of time to turn around if you react properly and quickly and get out of the downdraft.

5) You're flying an airplane through a canyon at 110 knots. You realize you can't make it out of the canyon. You roll into a 45-degree-bank turn. Will you be able to complete the turn successfully? What speed *should* you fly through the canyon?

Much like any other flying, this is situationally dependent. Obviously, you're going to fly Vx, to maximize the amount of climb in the shortest distance (also would apply to a turn in this case), but will you complete it? Maybe, if the canyon is big enough. Wingover? Maybe, I'd like to avoid the situation in the first place.

I'm sure your primary training was better than most in regards to high-DA flying, because you were doing it. Most flatlander primary training consists of (in the voice of Mr. Mackey, the school counselor in South Park) "Density altitude's bad, mmmmkay?" However, none of the above knowledge is on the PTS, and as someone who has repeatedly complained about the "difficulty" of the private pilot checkride, I'm surprised that you think it should be added.

Well, I think that this is all stuff covered in the private pilot knowledge tests anyways, but there is a benefit to knowing performance figures, but I still can't see a benefit to knowing S-Turns or turns around a point for a purely recreational private pilot. Different topic tho.

 

[murphey]

The Colorado directory and maps are usually available at any Colorado airport. Last year at OSH they completely ran out of the directories. This year, more were printed and lots more will be taken to OSH for the Colorado booth. Stop by the NASEO booth.

 

[murphey]

Ditto on Sydney - plan on half a day or better to even scratch the surface of Cabela's. When you call in on CTAF, have the FBO request the Cabela's shuttle for a free ride over and back. There's a couple decent motels in town.

Have the FBO request the shuttle? Before you finish your position call, the office will be asking you if you want the shuttle!

The area around Cabelas has been built up over the past few years - no need to go into town itself, other than sightseeing.

 

[flyingcheesehead]

1) Winds are calm. Which side of a mountain/ridge will have updrafts, and which will have downdrafts? Bonus question: How far from the mountain will these updrafts be felt?

I'm going to assume the answer lies in heat. The sun will rise in the east and set in the west, so in the morning, with calm wind, you'll have updrafts on the east side of the mountain, and vice versa in the evening.

Very good - Except the effect is mostly felt on the south and west faces. The east faces only get a very small amount of heat going, and not very strong, before noon.

The distance? As far away as you can feel? I don't know that one.

100-300 feet.

2) You camp overnight at a backcountry airstrip in a canyon (say, Johnson Creek above), and you want to fly out to breakfast in the morning. Which way should you expect the wind to be blowing in the morning when you take off? How about in the evening when you fly back in to have a cookout at your campsite?

This is one of the questions that doesn't need an answer, as you can observe the winds before you takeoff/land.

Okay, so I picked a weak scenario. Let's say that you need to get out of the backcountry for whatever reason (I'm not feeling particularly creative at the moment ), and there's two windsocks on either end of the strip pointing in opposite directions (which is fairly common in the backcountry). To make the necessary climb gradient to get out of the canyon, you will need a headwind. Which way do you go?

3) You're flying an Archer (180hp) from a strip at a DA of 8,000 feet. What is your approximate available horsepower?

I'd need the book to answer this, but the answer will be "considerably less" than the horsepower at sea level.

Good start, but does your airplane match the book? What if you don't have the book?

3a) Maximum gross weight on your Archer is 2550 pounds. How much weight must you remove from the cabin to achieve book performance at 8,000 feet DA?

Again, I'd need the book to answer definitely, but I would assume the answer lies somewhere near "It can't be done."

I can't do it, but Tristan could.

3b) Your Archer can climb 1,000 fpm at sea level at max gross. What will be your rate of climb at 10,000 feet DA?

I'd need the book to answer that question. Considerably less, probably around 300fpm, would be my guess, and I may be overstating that.

Yep. But again, this is about YOUR airplane, not the book. Remember, the book was written by marketing people looking at the brightest data gathered by a professional test pilot with a brand-new, undented, perfectly rigged, clean airplane. And there are ways of calculating things that aren't in the book.

4) You encounter a downdraft and you begin descending at full power and Vy. What should you do?

Ahh, here we go. You turn away. You were smart enough to not approach that ridge at 90 degrees, right? You'll have plenty of time to turn around if you react properly and quickly and get out of the downdraft.

That's one possible answer, but I did a poor job of asking the question.

Let's say you're in a narrow canyon without enough room to turn (never mind how you got there in the first place). It's very long, but narrow enough that a turn would be inadvisable. Due to DA, your maximum rate of climb is 200fpm, and the updrafts and downdrafts are equal in magnitude and at least 200fpm. What do you do when you hit a downdraft?

5) You're flying an airplane through a canyon at 110 knots. You realize you can't make it out of the canyon. You roll into a 45-degree-bank turn. Will you be able to complete the turn successfully? What speed *should* you fly through the canyon?

Much like any other flying, this is situationally dependent. Obviously, you're going to fly Vx, to maximize the amount of climb in the shortest distance (also would apply to a turn in this case), but will you complete it? Maybe, if the canyon is big enough. Wingover? Maybe, I'd like to avoid the situation in the first place.

Situationally dependent? Not really. It's math. The answer is the same for any airplane, too.

As far as the climb goes, let's say you're flying that Archer still. Book says Vs0=53 KCAS, Vs1=59 KCAS, Vx=64 KIAS, Vy=76 KIAS, Vfe=100 KCAS, Va=108 KCAS.

You have two choices: Turn around, or climb like mad, straight ahead. What speed would you fly for each? Answer in numerical form, with KCAS or KIAS.

Well, I think that this is all stuff covered in the private pilot knowledge tests anyways,

Actually, none of it is, beyond "look it up in the book." This is about a lot more than book performance figures. We're flying mostly 30+ year old airplanes, and in fact the backcountry strips have a lot more 50-year-old airplanes: Cessna 180's, Super Cubs, etc. The book is a nice idea, but the book may make it over the ridge when the airplane won't, or vice versa.

Is the point made yet, that you might actually learn something if you took a mountain flying course?

 

[SkyHog]

Is the point made yet, that you might actually learn something if you took a mountain flying course?

If the point that is made is:
"If you do something stupid, like flying up a box canyon in high wind, you will need a calculator to figure out speeds" then yes, the point was made.

If you were trying to show that a mountain flying course teaches you things that you shouldn't already know, then no, I don't think the point was made.

But I can concede this: If someone is not comfortable flying in mountains, and thinks a mountain flying course will help, great! Spend the money on it, and gain confidence. That's what you'll get - confidence and some experience in mountains.

But, where do we draw the line? Do I need to take a flatland course to learn how to manage a complex airplane properly in an area where MP can really get away from you, or can I rely on the training that I received when I got my Complex Endorsement? What about flights over water, or along NDB airways, both of which have their own challenges and things to know that don't apply out here. Do I need a special course to teach me how to do that stuff too, or can I rely on the things taught during primary training?

 

[flyingcheesehead]

If the point that is made is:
"If you do something stupid, like flying up a box canyon in high wind, you will need a calculator to figure out speeds" then yes, the point was made.

Sigh. So I picked ****ty questions and didn't ask them very well. Are you saying it's not important to know exactly how YOUR airplane will perform in the mountains? That it's not important to know what the air is doing?

Seriously, you ought to take a mountain course. Even you would learn something. And you'd have fun too. I wasn't sure what I would get out of it until I did it, and now I'm very glad I did.

But, where do we draw the line? Do I need to take a flatland course to learn how to manage a complex airplane properly in an area where MP can really get away from you, or can I rely on the training that I received when I got my Complex Endorsement? What about flights over water, or along NDB airways, both of which have their own challenges and things to know that don't apply out here. Do I need a special course to teach me how to do that stuff too, or can I rely on the things taught during primary training?

Apparently. How is MP going to "get away from you?" And really, none of the things you mentioned are particularly difficult. Flights over water are a yes or no question that every pilot must answer for themselves, and if the answer is yes, they need to decide under what conditions it's a yes. There's no "right" answer. And what's so challenging about NDB airways? Radio navigation is part of primary training and is in the PTS, mountain flying is not. If someone didn't learn NDB's in primary because they didn't have one, it's fairly easy to learn. And I've never seen an NTSB report that said "they got killed because they flew an NDB airway without the proper knowledge" or the like. People crash in the mountains all the time.

The reason mountain flying gets a course, is that it's something that combines weather, airflows, performance, etiquette, safety, and getting to know your airplane very well. There's a lot to be learned, if you'll open you mind to it.

 

[SkyHog]

Sigh. So I picked ****ty questions and didn't ask them very well. Are you saying it's not important to know exactly how YOUR airplane will perform in the mountains? That it's not important to know what the air is doing?

Of course not. To know what YOUR airplane will do, you pay attention to it, which everyone should do anyway. So the answer to your "How fast will your airplane climb at a DA of 10,000ft" would be "as fast as you can climb at either Vx or Vy depending on what you're trying to do (btw, Vx and Vy are usually pretty close to same at that altitude)."

Seriously, you ought to take a mountain course. Even you would learn something. And you'd have fun too. I wasn't sure what I would get out of it until I did it, and now I'm very glad I did.

Fun, yes. I have flown with an instructor in mountainous areas (try flying out of KTEX in a normally asiprated C172 with an instructor aboard). It may not have been an out and out "mountain fly course" but for all intents and purposes, it fits the bill.

What did I learn? How to judge windflow mostly....which I had learned flying around the Albuquerque area just fine. I also learned how to identify a pass vs. a deadend. You know what works just as well? Looking at the sectional and seeing the }{ logo on it with the words "XXX Pass" next to it.

It really is all about flying smart. Don't push the plane into areas it can't handle, don't push into the edges of the flight envelope. Always leave an out. Sounds like flying in any other situation to me.

I don't mean to be disrespectful to ya, Kent, but seriously, you're preaching knowledge from one trip through the mountains to a man who has to fly through mountains to go anywhere except dead south. I know what I'm talking about, and I say again: If you are lacking confidence in your own pilot skills, take a mountain flying course. It will probably boost your confidence up to a point where you can cope with flying through what will be the combination of the most beautiful, scary, and fun day of your life.

If, however, you have an understanding of why things happen in your airplane, just fly smart. That's all it takes.

Apparently. How is MP going to "get away from you?"

Try to take a Piper Arrow and exceed the maximum Manifold Pressure on the ground in Albuquerque some day. You'll see quickly that it ain't happening, so when doing the complex endorsement, you are told what will happen elsewhere.

And really, none of the things you mentioned are particularly difficult. Flights over water are a yes or no question that every pilot must answer for themselves, and if the answer is yes, they need to decide under what conditions it's a yes. There's no "right" answer.

That is exactly what mountain flying is: a series of yes or no questions. Anytime you say no, you turn back to where you came from (which is safe, you just came from there).

And what's so challenging about NDB airways? Radio navigation is part of primary training and is in the PTS, mountain flying is not.

I still have yet to hear anything that is pertinent to flying in the mountains that is not part of primary knowledge - be it weather, or flight characteristics, or airport operations....so, I'll volley it back: Wat's so challenging about flying mountains? Weather knowledge is part of primary training and is in the PTS.

If someone didn't learn NDB's in primary because they didn't have one, it's fairly easy to learn.

Indeed it is, Kent....indeed it is. I'll say the same about mountains.

And I've never seen an NTSB report that said "they got killed because they flew an NDB airway without the proper knowledge" or the like. People crash in the mountains all the time.

People crash in the flatlands all the time too.

The reason mountain flying gets a course, is that it's something that combines weather, airflows, performance, etiquette, safety, and getting to know your airplane very well. There's a lot to be learned, if you'll open you mind to it.

Of course there is, but its all stuff that you can find yourself (like any other knowledge), or things that you SHOULD have been taught as a primary student. Density Altitude calculations. Mountain waves, turbulence, updrafts/downdrafts, airport operations, one way strips, checking weather reports, navigation by sectional.

What did I miss? It seems so cut and dry to me.

 

[gkainz]

Back to the original question - Hey Geico, where are you and what did you decide?

 

[flyingcheesehead]

Of course not. To know what YOUR airplane will do, you pay attention to it, which everyone should do anyway. So the answer to your "How fast will your airplane climb at a DA of 10,000ft" would be "as fast as you can climb at either Vx or Vy depending on what you're trying to do (btw, Vx and Vy are usually pretty close to same at that altitude)."

I guess I'd rather know what my airplane will do in the mountains before I get there. And it wasn't about paying attention to climb rates - The things we mainly did were in slow flight, seeing where the airplane actually stalls vs. where it's supposed to stall, etc. The flight portion didn't deal with most of the things in the "quiz" that was all on the ground.

I also learned how to identify a pass vs. a deadend.

How's that?

You know what works just as well? Looking at the sectional and seeing the }{ logo on it with the words "XXX Pass" next to it.

Which works great, unless you screw up and make a wrong turn somewhere and aren't where you think you are. Not a very likely scenario in most areas, but up there in Idaho there aren't as many mountains/ridges that are distinguishing, they all kinda look the same and are packed close together.

I don't mean to be disrespectful to ya, Kent, but seriously, you're preaching knowledge from one trip through the mountains to a man who has to fly through mountains to go anywhere except dead south.

And you're preaching that a mountain flying class is worthless to anybody, regardless of where they trained. The difference is, I have experienced a mountain flying course. You have not experienced a mountain flying course, yet you somehow "know" that it's not worthwhile.

I know what I'm talking about, and I say again: If you are lacking confidence in your own pilot skills, take a mountain flying course.

It has nothing to do with confidence. Had I not been reading these boards, I probably wouldn't have even known there was such a thing as a mountain flying course, and I would have launched on the trip anyway. Even knowing there was a mountain flying course, I didn't know if I'd really get anything out of it, but I decided to listen to those who had done it and said good things about it and give it a try. I was surprised how much I learned. I bet you would be too, especially since you think you wouldn't learn anything.

If, however, you have an understanding of why things happen in your airplane, just fly smart. That's all it takes.

Then why is it that the most experienced Idaho mountain pilots always ask others what to do when they go to a strip they haven't been to before? And why is it that a mountain-flying expert who had more time than you and I combined will probably ever have still managed to crash, twice, and kill himself on the second one? Flying smart is the biggest part of the equation, but "that's all it takes" reeks of complacency.

Try to take a Piper Arrow and exceed the maximum Manifold Pressure on the ground in Albuquerque some day. You'll see quickly that it ain't happening, so when doing the complex endorsement, you are told what will happen elsewhere.

Fill me in, then - I can't exceed the maximum manifold pressure in an Arrow on the ground here, either.

I still have yet to hear anything that is pertinent to flying in the mountains that is not part of primary knowledge - be it weather, or flight characteristics, or airport operations....so, I'll volley it back: Wat's so challenging about flying mountains? Weather knowledge is part of primary training and is in the PTS.

In a general sense, yes. But mountain weather is not. Sure, the books talk about mountain waves and the like, but more in a big-picture sense. I had never heard of the venturi effect (as it applies to mountain flying, not carburetors) before the mountain course, for example.

Indeed it is, Kent....indeed it is. I'll say the same about mountains.

Okay, I'll give you that - It's not hard to learn, but it does take a little more time. Nobody's ever written an entire book on NDB navigation, have they?

People crash in the flatlands all the time too.

Sure, but they don't crash *because* they're in the flatlands.

Of course there is, but its all stuff that you can find yourself (like any other knowledge), or things that you SHOULD have been taught as a primary student. Density Altitude calculations. Mountain waves, turbulence, updrafts/downdrafts, airport operations, one way strips, checking weather reports, navigation by sectional.

What did I miss? It seems so cut and dry to me.

Again, most of that is covered only in a very general sense during primary training. Yes, you can get that knowledge from a book (and reading the book was an important piece of the mountain flying course puzzle) but like most things flying, you don't just read the book and go do them, you get some dual as well. The real world isn't always like the book.

 

[murphey]

Somehow, I don't think Geico or others in spam cans was flying the past couple days (Friday & Saturday). It was agony to even get the dog to go out to the back yard. Looks like the weather will clear up on Sunday, so I may drive out to the airport and shovel out the airplane. Might even go flying.

April in Colorado. Dumped anywhere from 10-52 inches (I got about 14 inches in the back). Later this week? May make it to 80 F.

Shorts and flip flops in February. Down jackets and snow boots in April.

That's in Denver. Up in the mountains, that's another story.

 

[N801BH]

Go here: http://forums.aopa.org/showthread.php?p=964184#post964184 and look a the post with the sectional that includes togweetee pass.

It's not possible to approach that one at 45 degrees to the ridge. It's a funnel on BOTH SIDES. Thus, the need to learn the DETAIL DETAIL DETAIL approach to mountain flying.

I fly out here in Jackson Hole Wy several times a week.. This is Mountainous terrain for sure but common sense and a knowledge of weather can get you alot of safe flying.... Of course don't try this trick at home kiddies...

http://www.jhnewsandguide.com/article.php?art_id=4479

Tailwinds guys and gals.

Ben.

 

[Anthony]

Somehow, I don't think Geico or others in spam cans was flying the past couple days (Friday & Saturday). It was agony to even get the dog to go out to the back yard. Looks like the weather will clear up on Sunday, so I may drive out to the airport and shovel out the airplane. Might even go flying.

April in Colorado. Dumped anywhere from 10-52 inches (I got about 14 inches in the back). Later this week? May make it to 80 F.

Shorts and flip flops in February. Down jackets and snow boots in April.

That's in Denver. Up in the mountains, that's another story.

When I lived in Colorado, I would mow the lawn in the snow. Yeah, Spring can be unpredictable. LOVED IT!

 

[Everskyward]

April in Colorado. Dumped anywhere from 10-52 inches (I got about 14 inches in the back). Later this week? May make it to 80 F.

I got about 20 inches but at least half of it has already melted. Here's a picture I took yesterday afternoon and another one from about the same angle I took just now, less than 24 hours later.

 

[Anthony]

^^^^^^^


Look at that beautiful blue sky! I miss Colorado and will be back there as soon as I can be. The foibles of Colorado weather are much exagerated by the media. That's fine, it keeps the wusses and weenies out. I love when it snows at Broncos games and the announcers talk about how cold and bad the weather is in Denver. Morons.

 

[SkyHog]

OK, agree to disagree, this is a really dumb argument anyway (life's too short for dumb arguments!)

Take a mountain flying course everyone! It's the bee's knees!

 

[etsisk]

You need to put up a warning! I spewed coffee all over my puter!

Should I stay on the left or right side of the tunnel?

There's at least one hwy tunnel in CO that has caught a plane or two...

 

[Geico266]

Well, I just got back from ferrying a RV-9A, 0-320 from Portland, OR to Lincoln, NE. Stopped in Twin Bridges, MT for fuel, took 3.25 hours took on 27.3 gallons (8.4 gallons per our burn, capacity 38 gallons) average speed around 180 MPH, then to Gillette, WY in 2.3 hours, then Lincoln, in 2.2 hours.

Not a cloud in the sky the whole way until Lincoln, then broken at 5500. Tail wind the whole way. The scenery was unbelievable. Fresh snow, cold air, no turbulence. Just peaceful solitude with an 0-320 purring away at 2400 PRPM.

Just a very special trip, one for the books.

Thanks to all who gave me advice and planning tips. Very nice to know the POA crew is there to help.

Now I'm washing clothes and planning on leaving at 0600 for SnF!

Washington state to FL in 3 days.

 

[flyingcheesehead]

Well, I just got back from ferrying a RV-9A, 0-320 from Portland, OR to Lincoln, NE. Stopped in Twin Bridges, MT for fuel, took 3.25 hours took on 27.3 gallons (8.4 gallons per our burn, capacity 38 gallons) average speed around 180 MPH, then to Gillette, WY in 2.3 hours, then Lincoln, in 2.2 hours.

Not a cloud in the sky the whole way until Lincoln, then broken at 5500. Tail wind the whole way. The scenery was unbelievable. Fresh snow, cold air, no turbulence. Just peaceful solitude with an 0-320 purring away at 2400 PRPM.

Just a very special trip, one for the books.

Nice!

Biggest problem with a trip like that is that after all the beautiful scenery, you hit the flatlands and it gets soooooooooo boooooooorrrrriiiiiinnnnngggg!

 

[gkainz]

with 20/20 hindsight, it would have most likely been an awesome flight over the mountains today - the storms have moved on, the sun is shining brightly, the temps are in the 60s at least and the snow is melting like mad.

Glad you had a good trip!

 

[Geico266]

with 20/20 hindsight, it would have most likely been an awesome flight over the mountains today - the storms have moved on, the sun is shining brightly, the temps are in the 60s at least and the snow is melting like mad.

Glad you had a good trip!

It was one of the best trips I have made, just beautiful.

 

[Capt. Geoffrey Thorpe]

That's one possible answer, but I did a poor job of asking the question.

Let's say you're in a narrow canyon without enough room to turn (never mind how you got there in the first place). It's very long, but narrow enough that a turn would be inadvisable. Due to DA, your maximum rate of climb is 200fpm, and the updrafts and downdrafts are equal in magnitude and at least 200fpm. What do you do when you hit a downdraft?

I assume the answer you were looking for is "push"?

 

[flyingcheesehead]

I assume the answer you were looking for is "push"?

Yep. Otherwise you'll spend more time in the downdrafts than the updrafts, and you won't climb. Push in the downs, pull in the ups to get as much help as you can.

Here's the quiz, with answers, as I originally wrote it:

1) Winds are calm. Which side of a mountain/ridge will have updrafts, and which will have downdrafts? Bonus question: How far from the mountain will these updrafts be felt?

Answer: The side the sun is shining on will have updrafts. This one should be fairly obvious. Bonus answer: Thermal lift usually extends 100-300 feet out from the face of the mountain and directly above the ridge.

2) You camp overnight at a backcountry airstrip in a canyon (say, Johnson Creek above), and you want to fly out to breakfast in the morning. Which way should you expect the wind to be blowing in the morning when you take off? How about in the evening when you fly back in to have a cookout at your campsite?

Answer: The wind will tend to blow from downstream (as in, wind is blowing upstream), or from lower elevation towards higher elevation. in the morning. As the sun rises, the canyon walls will begin heating from the top down, and the shallower upstream portions of the canyon will be fully lit long before the deep downstream portions. The cool air that collected overnight in the downstream portion will begin to flow upstream to replace the rising warmer air in the upstream portion. In the evening, the upstream part, being at a higher altitude, will begin cooling sooner and the winds will tend to flow downstream.

3) You're flying an Archer (180hp) from a strip at a DA of 8,000 feet. What is your approximate available horsepower?

Answer: A normally-aspirated aircraft engine loses around 3.5% hp per 1000 foot increase in DA. So, our 180hp engine at 8,000 feet has lost about 28% of its power, leaving 72% available. 0.72 * 180 = 129.6. So, your Archer has turned into a bit less than a Cherokee 140.

3a) Maximum gross weight on your Archer is 2550 pounds. How much weight must you remove from the cabin to achieve book performance at 8,000 feet DA?

Answer: Sea level power loading is 2550/180=14.666666... pounds per horsepower. At the 129.6 hp available at 8,000, to get book performance we'll need to reduce to 14.6666 lb/hp * 129.6 hp = 1,836 pounds. (For reference, in our Archers, just me and an hour of fuel is 1,905 pounds.)

3b) Your Archer can climb 1,000 fpm at sea level at max gross. What will be your rate of climb at 10,000 feet DA?

Answer: Rate of climb = (Excess HP * 33,000)/gross weight. So, at sea level, that means you have 77.3 excess hp available, and that it takes 102.7hp just to keep the plane level.

Now, at 10,000 feet DA you've lost roughly 35% of your available horsepower (63hp), so you're down to 117hp at full power. Thus, you have 14.3 excess hp available for climb. Plug that into the formula again, and your rate of climb will be a dismal 185 feet per minute. Now, you'd better pay close attention to where those downdrafts are likely to be, because many of them will be a lot more than 185 feet per minute!

4) You encounter a downdraft and you begin descending at full power and Vy. What should you do?

Answer: Push the nose over and increase airspeed. You will not outclimb the downdraft, so you want to get through it as fast as you can. Likewise, in rising air you want to pull the nose up even farther to slow down and maximize the time spent in the rising air. Holding altitude (or attempting a steady rate of climb) is one of the worst things you can do when flying through up and down drafts.

5) You're flying an airplane through a 1000-foot-wide canyon at 110 knots. You realize you can't make it out of the canyon. You roll into a 45-degree-bank turn. Will you be able to complete the turn successfully? What speed *should* you fly through the canyon?

Answer: The formula for turn radius is v^2/(11.26*tan(bank)). At 110 knots and 45 degrees of bank, turn radius will be 1,074.6 feet, so the full diameter of the turn will be 2,149.2 feet, nearly 1/2 mile. Add on at least 50 feet for the span of the outer wing as well (on a 172, for example, that would have you with your wingtip 7 feet off the canyon wall on both ends of the turn).

At 100 knots, turn radius will be 888 feet.
At 90 knots, turn radius will be 719 feet.
At 80 knots, 568 feet.
At 70 knots, 435 feet. This is enough for your average single to make the turn, provided they started close enough to one wall. So, you probably shouldn't be flying faster than 70 knots in this particular canyon! (Ahem, Corey Lidle)

 

[gismo]

3a) Maximum gross weight on your Archer is 2550 pounds. How much weight must you remove from the cabin to achieve book performance at 8,000 feet DA?

Answer: Sea level power loading is 2550/180=14.666666... pounds per horsepower. At the 129.6 hp available at 8,000, to get book performance we'll need to reduce to 14.6666 lb/hp * 129.6 hp = 1,836 pounds. (For reference, in our Archers, just me and an hour of fuel is 1,905 pounds.)

Your question was a bit ambiguous. From the answer you gave it appears that by "book performance" you really mean "sea level MGW (book) performance", i.e. the same climb rate as you'd get under standard sea level conditions at max gross weight.

3b) Your Archer can climb 1,000 fpm at sea level at max gross. What will be your rate of climb at 10,000 feet DA?

Answer: Rate of climb = (Excess HP * 33,000)/gross weight. So, at sea level, that means you have 77.3 excess hp available, and that it takes 102.7hp just to keep the plane level.

Now, at 10,000 feet DA you've lost roughly 35% of your available horsepower (63hp), so you're down to 117hp at full power. Thus, you have 14.3 excess hp available for climb. Plug that into the formula again, and your rate of climb will be a dismal 185 feet per minute. Now, you'd better pay close attention to where those downdrafts are likely to be, because many of them will be a lot more than 185 feet per minute!

IIRC it takes more power to keep the airplane in the air at higher altitudes than it does at sea level because you have to fly at a higher TAS. That's assuming that the IAS decrease in Vy is less than the increase in TAS-IAS. If I'm remembering correctly you'd have even less climb rate available.

4) You encounter a downdraft and you begin descending at full power and Vy. What should you do?

Answer: Push the nose over and increase airspeed. You will not outclimb the downdraft, so you want to get through it as fast as you can. Likewise, in rising air you want to pull the nose up even farther to slow down and maximize the time spent in the rising air. Holding altitude (or attempting a steady rate of climb) is one of the worst things you can do when flying through up and down drafts.

Got any suggestions on how much to increase your IAS in this situation? Some amount of increased speed (over Vy) will generally improve things but too much and you'll make things worse.

5) You're flying an airplane through a 1000-foot-wide canyon at 110 knots. You realize you can't make it out of the canyon. You roll into a 45-degree-bank turn. Will you be able to complete the turn successfully? What speed *should* you fly through the canyon?

Answer: The formula for turn radius is v^2/(11.26*tan(bank)). At 110 knots and 45 degrees of bank, turn radius will be 1,074.6 feet, so the full diameter of the turn will be 2,149.2 feet, nearly 1/2 mile. Add on at least 50 feet for the span of the outer wing as well (on a 172, for example, that would have you with your wingtip 7 feet off the canyon wall on both ends of the turn).

At 100 knots, turn radius will be 888 feet.
At 90 knots, turn radius will be 719 feet.
At 80 knots, 568 feet.
At 70 knots, 435 feet. This is enough for your average single to make the turn, provided they started close enough to one wall. So, you probably shouldn't be flying faster than 70 knots in this particular canyon! (Ahem, Corey Lidle)

The minimum radius turn will occur at the airspeed and bank angle that puts you just above a stall at the maximum load rating of the airplane (e.g. 3.8g / 75 deg / >1.95 * Vs). If you prefer to stay with a 45 degree bank for comfort the best speed would be slightly more than 1.19 * Vs. A good compromise is to fly a 60 degree bank with the stall horn sounding intermittantly. Initial speed isn't much of a factor unless the walls of the canyon are inversely tapered and you wait until the last minute to turn as you can just pull up to reduce speed quickly and roll into the turn as you approach the proper speed. Also FWIW your calculations ignore the lateral distance wasted rolling into and out of the turn. The turn in loss can be eliminated if you start away from the canyon wall and head towards it then turn away at the last second but that sounds pretty scary. The rollout loss can be eliminated by beginning the rollout when your wings are perpendicular to the wall then turning in the other direction before hitting the other side. Ignoring those tricks, you will benefit from using as much roll rate as the plane can manage.

Given enough room ahead (and below if your power is too limited) it's possible to turn around with less canyon width by using the vertical. You could make it out with a foot more than your wingspan with an Immelman if you were skilled enough (not me!), less than that if you can do half a loop in knife edge flight. Seriously though, you probably could pull off a wingover which allows for a steeper bank angle by utilizing the plane's momentum to allow a significant unloading of the wings and subsequent lower stall speed in the turn.

 

[flyingcheesehead]

Your question was a bit ambiguous. From the answer you gave it appears that by "book performance" you really mean "sea level MGW (book) performance", i.e. the same climb rate as you'd get under standard sea level conditions at max gross weight.

That would be a better way of putting it, yes. Better yet would be "the performance you're used to down in the flatlands."

Got any suggestions on how much to increase your IAS in this situation? Some amount of increased speed (over Vy) will generally improve things but too much and you'll make things worse.

I think Tony would have a better answer for this than me, it's almost a glider question. In fact, I bet the guys who get the most performance out of their airplanes in the mountains are the glider guys. I played with ridge lift some, but I didn't encounter a situation like was described in this question. Part of the course was about avoiding those situations in the first place.

The minimum radius turn will occur at the airspeed and bank angle that puts you just above a stall at the maximum load rating of the airplane (e.g. 3.8g / 75 deg / >1.95 * Vs).

Yep, I had a thread about this a few months ago, and put together a radius vs. speed vs. bank angle spreadsheet for kicks. I think it was 74 degrees with the stall warning screaming to get the best turn for normal category, and utility category only allowed another degree or two.

Given enough room ahead (and below if your power is too limited) it's possible to turn around with less canyon width by using the vertical. You could make it out with a foot more than your wingspan with an Immelman if you were skilled enough (not me!), less than that if you can do half a loop in knife edge flight. Seriously though, you probably could pull off a wingover which allows for a steeper bank angle by utilizing the plane's momentum to allow a significant unloading of the wings and subsequent lower stall speed in the turn.

I'm not sure how effective those would really be when you're already on the edge of the performance envelope. IE, you wouldn't get much vertical going before you had to give it back up, and you might not have enough to help the turnaround maneuver in any of the cases above. It'd sure be interesting to see how an Extra performs at 15,000'!

 

[Capt. Geoffrey Thorpe]

I'm not sure how effective those would really be when you're already on the edge of the performance envelope. IE, you wouldn't get much vertical going before you had to give it back up, and you might not have enough to help the turnaround maneuver in any of the cases above. It'd sure be interesting to see how an Extra performs at 15,000'!

There was a thread on "canyon turns" that referenced a description by Sparky Imeson, but that link is now dead.

IIRC it was nose up, roll, unload the wing as speed decays, load back up as speed picks up. The turn is made a minimum speed - likely below the "offical" stall speed for a level turn.

As described, it wasn't anything like a hammerhead. Kinda like a wingover, but not really.