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CT / Sport PIlot - Mountain Flying Tips


Ed Cesnalis

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The attached photo demonstrates a primary mountain flying issue, climb performance and ability to clear terrain on initial climb.

 

Minimizing gross weight will have a lot of impact beyond that the biggest issue is, once again prop pitch. If your climb performance is inadequate check your RPM. If your RPM is less than 5,500 than you are not using all the horse power available from your engine.

 

Climb can be enhanced in a CT by flying in areas of lift but some background in soaring and micro-meteorology is needed. I can almost always find some lift but it often means climbing along ridges and flying very close to the terrain. Looking for lift I might inadvertently fly into a rotor zone and its good to have that experience as well.

 

Speaking of rotor zones, the rotor zone can be the other side of the coin. The same terrain that requires the steep climb on departure will require a steep descent on the way back and if it is on the lee side then that descent might have to penetrate a rotor zone. unsure.gif If you can visualize the rotor you have a chance of avoiding it otherwise I tend to buckle up and throttle back.

 

I see your videos, how about some tips from you guys up north?

post-6-0-47491300-1347735453_thumb.jpg

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All I can add is that mountains on one side and high desert on the other makes for a light-sport ass-kicking. I had 3 hours of it coming down from Washington to California. I followed highway 97 through Oregon and hit mountain waves that climbed me 1000 feet per minute for longer than a minute.

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:excl: Internet advice on Mountain Flying should be considered more dangerous than Mountain Flying itself. :excl:

Please take this with a grain of salt. I'm just a guy with a plane.

 

 

Charlie Tango points out that soaring experience is the best teacher. I agree. Strong personal mentors and a careful eye are another other factor, alongside thoughtful consideration of the physics of micro meteorology. There is no substitute for flying lots. Strictly begin with benign conditions and go from there. If you watch my videos, you will see that the up close and rocky flights are all on windless days. Tight mountain valleys are no place to be when the wind is blowing. Consider that most many soaring flights are high above the terrain!

 

Augering through the air as our machines do does little to demonstrate what that air is really doing, other than occasionally kicking us in the ass. A sailplane teaches the fundamentals of invisible convective and mechanical flow.

 

Power is important, and here in the Great White North we have the advantage of inflight variable pitch to optimize that power input. I'd consider this to be essential to mountain flying. That said, it is exactly that power that lends the possibilty of entering rough or dangerous conditions in the absence of other considerations.

 

 

 

So what do I try to consider? This a tough thing to do in a Fast Reply. I welcome the opportunity to discuss.

 

It all depends on what you are trying to get out of your flight..... an exploration of mountain grandeur, or a transit from point A to point B?

 

I mostly go exploring, but I only do so on days with mild winds aloft, typically before convection starts. Fifteen or Twenty knots at ridge top keeps me from most of my favourite places as its just not comfortable to get accelerated as ultralights tend to do. Otherwise, beyond going (appropriately)high and staying high (oh so boring) the things I consider are:

 


  1.  
  2. What are the energy inputs for any given day?
  3. What is the wind direction/speed, and variance with altitude? This relates to mechanical lift and subsidence, lee wave and rotor locations. There is no fixed fomula for what any combination of terrain and wind will whip up, only visualization from what is to what might be, and remembrance of what once was :o .....
  4. What is the forecast for those winds, how will they change through the day?
  5. Instability? what is the daytime heating profile, how and when will the convection build, and how will it interact with the overprinted wind direction and speed? What is the aspect of terrain being heated? What path is that warmed air most likely to follow? Thermals typically flow up slopes and release at ridge top. How will this then interact with the prevailing wind? Constructively? or turbulently?
  6. Is there potential catabatic influence of glacial air?
  7. What are the wind indicators on the ground?
  8. Keep your head outside of the cockpit! Gizmos are distracting.
     

I'm sure there is much more to be added.....

 

caution above all else.

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The light sport pilot / aircraft rule was not written to enhance safety when mountain flying.

 

At first there was an absolute 10,000' altitude limitation for sport pilots that did permit crossing the Sierra Nevada but with only 500' of clearance deep in a mountain pass. Now there is a 2,000' AGL exception but how does one interpret this? If a strict interpretation is used then the exception remains quite limiting but some use a very liberal interpretation that would mean they are legal at times when they are above 10,000' and have more thane 2,000' directly below them. I expect this question will be answered if and when FAA attorneys write a legal opinion on the matter or ultimately when a judge makes a ruling.

 

Another part of the rule that limits safety when mountain flying is the 120kt limit for the aircraft. Speed capability and climb capability come from the same place, "available power." Speed is generally limited by limiting power and as a result climb performance is limited as well. Most of the fatalities that I see around here are related to climb performance or a lack of it. Most common are incidents resulting from take-offs and initial climbs done at "full rich." ( This is a personal observation not the result of research. )

 

The light sport aircraft weight limit which results in lightly wing loaded designs comes into play in wind sheer. This is an issue when in the lee of terrain as well on high altitude take-offs and landings. 20 hours of training are required to get a light sport certificate compared to 40 for a private pilot yet flying a light sport aircraft in turbulence associated with large mountain ranges can be far more advanced than what a typical private pilot ever sees in his training.

 

The light weight gives me grief trying to hold altitude or even flying an approach. Typical for me when turning base to final at 500' AGL, 30 degrees and 55 kts, throttle closed and my CT might climb instead of descend. angry.gif

 

Like C ICEY I'm just a guy with a CT, I'm just trying to share my experiences flying it in the Sierra.

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Hmm...anyone here get a light sport certificate (without a previous ticket) in anything close to 20 hours? Or am I just a slow learner?

 

This is very interesting for a flat lander. (Pun may be intended.) Thanks all.

 

My guess is that getting a light sport certificate in 20 hours is not necessarily difficult but it can be complicated by things like airspace and aircraft.

 

I bet that getting a light sport certificate in a CT might be more difficult than getting a private pilot certificate in a Cessna 172.

 

Fact for flat landers: At times you can fly your CT into rising or sinking air that cannot be overcome and your only option is to control your airspeed and go for a ride.

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Hmm...anyone here get a light sport certificate (without a previous ticket) in anything close to 20 hours? Or am I just a slow learner?

 

This is very interesting for a flat lander. (Pun may be intended.) Thanks all.

 

I got my SP in 45 hours, including the check ride, and that was with a fair amount of prior flying experience. I am thinking the 20-hour figure is an absolute minimum requirement and is probably not often achieved, nor should that be a goal IMHO. Quality, not quantity (or lack thereof), should be paramount. It bothers me when schools promote the 20-hour figure.

 

Soaring and mountain free-flight experience definitely helps with mountain LSA flying. Thermals, ridge lift, rotors, waves, valley winds, etc. It's very good to be able to visualize all of these things as you plan, fly, and adjust your mountain route. I come from a paragliding background where these things are even more important, so a lot of this stuff is second nature. There are some good books on the topic... an excellent one from the paragliding world:

 

http://www.amazon.com/Thermal-Flying-Paraglider-Glider-Pilots/dp/3000202331

 

Of course much of the info would apply to flying anything in the mountains. Anyone have any good recommendations on airplane-specific books on mountain flying?

 

Here's a fun trick with thermals that even works in the flats: next time you are climbing out on an active day, when you get into a good, organized thermal (climb rate goes way up for more than just a few seconds), pitch up, go to flaps 0 or 15, slow down to 50 or 55kts, and circle tightly to stay in the lift. Keep it coordinated and don't stall, but keep it slow to minimize turn radius. Build a mental picture of the lift as you circle and the climb rate varies. Adjust your circles to get into the center of the thermal and maximize the climb rate. You'll finish your climb much faster and save some fuel while you're at it. If you stay in the thermal, it won't be very turbulent... you'll just be going up like a rocket. This works really well at high DA. On a recent afternoon climb out of Roswell, NM, I was able to get over 1000fpm instead of the 300fpm I was getting flying straight.

 

post-668-0-36862000-1347827568_thumb.png

 

-Russ

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Another advantage that we northerners have is that typically field elevations are relatively low, while the peaks tower about.

 

Nelson BC (CZNL)is ony 1750 ASL, (Albertans start at perhaps 4000') with the highest accessible peaks at about 12,000. density altitude is not really a problem with the CT. mid summer days to mid 30's Celsius. hot 'nuff.

 

The west face of Mount Robson is about 10,000 feet from the valley floor to the summit. Truly a climbout to remember. (and I know Mt Whitney, starting from below sea level, but I'm biased here!)

 

 

http://photoshare.shaw.ca/messages/viewimage/36494_NltFwS1163011819ZdNfUV/gallery/1817885/page/4/15

 

Mount Robson North face, with links to other nice shots

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I don't know for certain, but a part of the problem is that some CFIs including mine don't understand the difference between light sport and private. I know when I took the written I had learned things that would not be on the test. I also learned at a towered class D airport and we had to be 15 nm away before we could do practice maneuvers. I would be surprised if anyone without previous experience could become proficient in 20 hours...but then I have never flown a Cub.

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Whatever the license, or however long it took, a freshly minted ticket is merely the license to begin learning.

 

severe mountain conditions are easily capable of overwhelming fresh and largely unfamiliar skills especially if the micromet creating them is not understood.

 

 

btw, that speed limit which I presume is the reason that inflight variable or constant speed is prohibited is a rule that appears to be very arbitrary.... hard to understand from my perspective, and completely at odds to advancement of the industry.

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Whatever the license, or however long it took, a freshly minted ticket is merely the license to begin learning.

 

severe mountain conditions are easily capable of overwhelming fresh and largely unfamiliar skills especially if the micromet creating them is not understood.

 

 

btw, that speed limit which I presume is the reason that inflight variable or constant speed is prohibited is a rule that appears to be very arbitrary.... hard to understand from my perspective, and completely at odds to advancement of the industry.

 

I believe the reason for prohibiting adjustable props is "avoiding complexity."

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I spent 2 hours flying in the Sierra Nevada this weekend, yesterday winds were gusting over 50mph and it brings up Mountain flying and turbulence. Some of my thoughts:

  • Ovoid turbulent conditions through flight planning.
  • The wind arrow on my GPS / EFIS is one of my best indicators of where lee side turbulence exists.
  • The relative wind direction compared to the general ridge direction can mean smooth winds if aligned and turbulent winds if range is 90 degrees to the wind.
  • If I think I should turn around because it is too rough then I should turn around. My worst flights have been on a bet that it will get better.
  • When cruising the length of a mountain range do it on the windward side.
  • A leather helmet would be nice to have in the cockpit.

 

What about downdrafts?

 

Most of the time sinking and rising air means that I abandon the idea of holding altitude and as long as I have adequate margin the climbing and sinking even out. However there are times when sinking air can put you in jeopardy.

 

If I am unable to maintain altitude when approaching a ridge ( hopefully I was crossing at an angle ) and I am not comfortable with the resulting clearance I simply turn away hoping to fly out of the sinking air and regain my ability to climb. If I was fine until I encountered the rapid sinking then the area behind me might be a good place to go to get out of the sink.

 

I will generally give up altitude to get out of the sinking air.

 

Nugget_-208_Owens_Valley_Sailplane__Record.jpg

 

 

I know people that have flown this valley in a 206 wit the stall warning going off for 1/2 hour as they fought the sinking air with climb power at minimum speed. I would assume that the sink was in a zone along the Sierra and change my distance from it.

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I know people that have flown this valley in a 206 wit the stall warning going off for 1/2 hour as they fought the sinking air with climb power at minimum speed. I would assume that the sink was in a zone along the Sierra and change my distance from it.

 

The lift and sink should most likely form a lozenge shape parallel downwind of the terrain that generates it.

 

I bet that less than a kilometer down wind they would have been amazed at their good fortune by climbing at speed, glassy smooth, and throttled right back. The 'flip side' is getting too low and drifting into the bad half of rotor.

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I don't have much to add about mountain flying. I follow the conventional advice, 45Deg approach, turn parallel to dwell in updrafts, dive down perpendicular to the ridge to speed through downdrafts, etc.

 

The one thing I found after having done this alot, (a bunch of crossings of the rockies and about 50 of the high sierras) is that very often there are low clouds always hovering ~1000' over the peaks from pushed-up moist air. So it is often not possible to get very high up and 1500' anyway puts you above 14K in much of the Sierras. Instead of altitude, I make sure to carry speed. I want to cross at just below maneuvering speed, say 95kts indicated. That way I can chandelle up and away if needed. The reflex is to hold the stick back to keep climbing but it is a mistake. I constantly visualize where I will turn away to in the event of a nasty downdraft. When it is bad, it looks like this https://picasaweb.google.com/lh/photo/PGYt33D_m_nA4XS_mP16jtMTjNZETYmyPJy0liipFm0?feat=directlink

Of course the other bits are to be sure the other side (Fresno) has reasonable weather and dewpoint spread and that the clouds are 'bright' meaning they are thin in case you need to climb up through a hole.

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