Couple of questions

B

bdoss2006

Pre-Flight
Joined
Mar 1, 2025
Messages
72
Display Name
bdoss2006
Hola. New sport pilot with a few questions. First concerning mountain flying. With that in mind, know I live in Appalachia, so it’s smaller mountains compared to like the Rockies for example. About 5500 MSL at the highest or 3000 AGL. So I know when flying across a ridge, you are supposed to fly at a 45 degree angle. How does that work if the mountains are kinda random for lack of a better word and there aren’t defined long ridges, just peaks? There’s really no way to fly at an angle like that. If you are high enough is that less necessary since turbulence from the mountains is reduced? Also, what do yall consider the limit of flying in a valley? Like if you are flying into it sight see around 1000ft AGL, but there is a mountain to the side at near the same elevation you are at what distance would you want to be away from that mountain? Is it even safe to do that? Also, what’s the standard separation distance/procedure from other aircraft? I know the right of way rules, but what is the recommend distance of separation to maintain and how would you determine that?
 
Hola.

First, don’t discount the Appalachians. I learned to fly in New England, lived in Colorado for 20 years, and am now in North Carolina. The primary difference is density altitude and even that is related to how much power you have available.

Unfortunately, your question have “it depends” answers. There are almost always places to apply that 45° ridge approach. How close depends on wind direction and strength. Circling, shuttle climbs, and other techniques abound.

“Mountain flying,” even leaving out the back country component involves a collection of knowledge and techniques added to your toolkit, a number of which are not part of typical sport/private training unless the training takes place in that environment. You can probably find some basic online courses and Sparky Imeson’s Mountain Flying Bible is still the best book on the subject, but most are best served by having some practical instruction applying techniques. Have you looked into finding an instructor for some training?
 
bdoss2006 said:
So I know when flying across a ridge, you are supposed to fly at a 45 degree angle. How does that work if the mountains are kinda random for lack of a better word and there aren’t defined long ridges, just peaks?
Click to expand...
The guideline is to approach a ridge at a 45 degree angle and then depart it perpendicular. It helps to know the reason, which is to maximize your escape route. If you run into an issue while approaching the ridge, you only need a 90 degree turn instead of a 135 degree turn to get away from it. As you crest the ridge and turn perpendicular, you're minimizing the time near that side of the ridge. If the mountains are kinda random, then it's not a ridge and therefore other techniques apply.

As @midlifeflyer says, further study and instruction is a really good thing in this regard.

midlifeflyer said:
There are almost always places to apply that 45° ridge approach.
Click to expand...
How about a class B boundary where you're still trying to get a clearance. :)
 
bdoss2006 said:
Hola. New sport pilot with a few questions. First concerning mountain flying. With that in mind, know I live in Appalachia, so it’s smaller mountains compared to like the Rockies for example. About 5500 MSL at the highest or 3000 AGL. So I know when flying across a ridge, you are supposed to fly at a 45 degree angle. How does that work if the mountains are kinda random for lack of a better word and there aren’t defined long ridges, just peaks? There’s really no way to fly at an angle like that. If you are high enough is that less necessary since turbulence from the mountains is reduced? Also, what do yall consider the limit of flying in a valley? Like if you are flying into it sight see around 1000ft AGL, but there is a mountain to the side at near the same elevation you are at what distance would you want to be away from that mountain? Is it even safe to do that? Also, what’s the standard separation distance/procedure from other aircraft? I know the right of way rules, but what is the recommend distance of separation to maintain and how would you determine that?
Click to expand...
Was your pilot training where you are operating now? Bottom line is if the wind is up, don’t be flying an LSA in the mountains.
 
Last edited:
I can't recommend enough "Mountain, Canyon and Backcountry Flying" by Dick Williams and Amy Hoover. It is very well written by the best in mountain flying and explains why not just how to do things like the 45 degree crossing. Go grab a copy!

 
bdoss2006 said:
Hola. New sport pilot with a few questions. First concerning mountain flying. With that in mind, know I live in Appalachia, so it’s smaller mountains compared to like the Rockies for example. About 5500 MSL at the highest or 3000 AGL. So I know when flying across a ridge, you are supposed to fly at a 45 degree angle. How does that work if the mountains are kinda random for lack of a better word and there aren’t defined long ridges, just peaks? There’s really no way to fly at an angle like that. If you are high enough is that less necessary since turbulence from the mountains is reduced? Also, what do yall consider the limit of flying in a valley? Like if you are flying into it sight see around 1000ft AGL, but there is a mountain to the side at near the same elevation you are at what distance would you want to be away from that mountain? Is it even safe to do that? Also, what’s the standard separation distance/procedure from other aircraft? I know the right of way rules, but what is the recommend distance of separation to maintain and how would you determine that?
Click to expand...

The 45 deg angle is really to give you more options in case you run into a downdraft. There is no "rule" but here is a simple calculation you can do - a 25 knot wind deflecting downward by 20 deg will produce close to a 1000 fpm downdraft. How much the wind deflects down, and how far downstream it extends really depends on the terrain features and direction of wind, and this is where knowledge from local pilots help. Generally it is inadvisable to fly close to the ridge when winds aloft exceeds 25 knots. If you can fly 2000 ft above the peaks, then you can avoid most of these problems. This is the key difference between Appalachian mountains and the Rockies. You simply can't fly 2000 ft above the ridges in many of the Rocky mountain passes in a normally aspirated airplane. If your best climb rate is 200 fpm, encountering even a small downdraft will have serious consequences.
 
I recommend that if you are flying "in" the mountains (i.e., down near the ridge line) rather than well over them to get a mountain flying course. As others point out, the major difference on the Rockies is that you're at much higher density altitudes that not only decrease the performance for getting over the ridges, but may cap your highest altitude. If your ridges are topping at 5500, most light planes can just go well above them.

I learned to fly in Colorado and did a mountain course there. Years later when I was reading the information on how to get to the Navion flyin in Grand Junction, I was some what peeved at the rather cavalier routings given. I pointed out that we'd be lucky if we didn't lose somebody coming or going. This was sadly confirmed when the report of a friend and his family being killed enroute to that event in the mountains.

There's way more to it than just "cross the ridges at 45 degrees." Way more. You need to make sure your routes are sane for your equipment. You need to understand the peculiarities of mountain weather. You need to know when there are times you just will not be able to do it. You need to know how to recover if you screw up and end up in a place you need to retreat from.
 
So is there a certain altitude you could say it is mostly safe to cross perpendicular? 2000 AGL maybe? Also, what about flying Parallel to a mountain beside it? Or in a valley between two mountains? How can that be done safely if it even can?
 
bdoss2006 said:
So is there a certain altitude you could say it is mostly safe to cross perpendicular? 2000 AGL maybe? Also, what about flying Parallel to a mountain beside it? Or in a valley between two mountains? How can that be done safely if it even can?
Click to expand...
Every situation depends on so many factors. There's not a perfect altitude (below the flight levels) that always works in every situation. Parallel can be good or bad depending on which way the wind is blowing and the sun is shining. It's all in Dick and Amy's book. Seriously, just go buy a copy.
 
You must log in or register to reply here.
Back
Top