BASIC PREMISES OF MOUNTAIN FLYING

by Alan Negrin, CFI, MEI

The allure of flying into the back country of the Pacific Northwest or heading north to Alaska is compelling for many of us who fly Glastar and Sportsman aircraft. It may be what led us to build or buy one as the primary or at least one of the main missions for having one. They are of course one of the best airplanes anyone could want for doing so, but flying into this kind or terrain requires a new set of skills and awareness.

Probably the most basic premise for mountain and canyon flying is, Stay in a position to turn around to lowering terrain. The idea here is to not fly into a box canyon or other terrain that’s rising faster than our airplanes can climb and where we can’t safely turn around, also known as the point of no return.

There is a maneuver called the Box Canyon Turn that we all must be able to execute very well if we intend to fly into back country airstrips. We’ve no business flying in the mountains if we’ve never done one or we’re not really proficient and comfortable making this kind of turning maneuver.

The good news is that it’s pretty easy once you’ve done it a few times and most importantly for us in our community, the Glastar and Sportsman aircraft are phenomenal when it comes to executing a box canyon turn. Remember what we’re discussing here is not flying over mountainous terrain on a cross country, 2000 feet AGL, but down much lower, flying between ridges and usually through river a drainage.

The way I learned the box canyon turn was with full flaps, full power and a very steep bank angle. My first experience with this maneuver was in a Cessna 180 on straight floats during my initial CFI training. We were on our way back after a lesson to Kenmore Air Harbor and the instructor asked me if I knew what a box canyon turn was. He demonstrated one and then I practiced a few of them.

Even though we all know that the stall speed goes up as the bank angle increases, with full power in a Glastar or Sportsman and approximately 60 knots, you can easily turn the airplane around within the wingspan distance and if not, very close to it and not be anywhere near a stall. I have done many of them in the Sportsman and when I was working full time at Glasair Aviation, I would always include at least one on every demo flight for a prospective buyer. People are always amazed at how small the radius of the turn is. Now I include them as part of my transition training course.

When we learn to fly, we are always taught to be looking for a place to set the airplane down in case of an emergency that requires an immediate landing.

When we fly in the mountains, we must be also constantly watching the terrain, and looking for a way to escape to lower terrain, usually through a drainage area. Many of the airstrips in the mountains are located in a river drainage. That is where the most suitable terrain is usually located for an airstrip, and a lot of them are found in places where the river turns and has created a natural flat area. That is also why we see a lot of names like Big Bar, and Dug Bar on the charts and in the back country flying books like Galen Hanselman’s “Fly Idaho”.

Another term most pilots hear a lot is “Situational Awareness”. Flying in unfamiliar, mountainous territory can all look very similar. It’s very easy to turn up the wrong drainage looking for a passage way through or an approach to a back country strip and find yourself boxed in. A really good idea is to go there with someone who has been there before and really knows their stuff flying into the back country.

Before we get to the point-of-no-return, we reach the turn-around point which is the position where the aircraft can be turned around without impacting the terrain in a box canyon turn. The turn-around point occurs when the airplane is about 500-feet AGL while heading toward an area of rising terrain.

Don’t continue past the turn-around-point without reversing course and gaining additional altitude. Always, Always, turn away from the terrain! This is another very basic premise for flying in the mountains. If the wind is blowing strongly enough to provide mechanical lift, certainly do take advantage of that to help you climb.
Glider pilots learn all about finding different kinds of lift, which is what soaring, is all about. If you intend to fly in the mountains and have never flown a sail plane, I highly recommend it. You should go to a glider port that’s known for having good lift conditions, and even better if they have the kind of terrain that offers ridge lift soaring, which is way different than thermal or convective lift soaring.

A lot of places will offer glider rides but don’t have many days when you can experience what you really need to learn and that is, how to find and ride the lift upwards to gain altitude. All you get is just a sled ride back to earth. It can be fun, but it is not very useful for flying in the mountains.

Mechanical lift comes from the wind blowing across the ridges and providing up slope winds which you can use to gain altitude. Convective lift comes from rising warm air currents on days when there is instability in the air mass.

If you think there is mechanical lift present when flying in the mountains, the technique is to make a figure eight turning pattern. Start by turning away from the terrain and continue the turn so that you are now headed back in the opposite direction toward the terrain at a 45 degree angle. Continue until you encounter the lift but obviously don’t get so close that it’s unsafe. Turn to fly parallel to the ridge and continue for about a half mile and climb. You will feel the lift and see the vertical speed increase. Continue to make figure eights until you’ve gained enough altitude to safely continue past the terrain in the direction you want to go and avoid becoming intimately familiar with that terrain prematurely.

It’s important to stay in the area of lift, because if there is ridge lift present in the mountains, then there will also be downdrafts, otherwise known to soaring pilots as “sink”. And “SINK” you will if you encounter it, especially if you’re flying into rising terrain, even a Glastar or Sportsman, or any single engine airplane can be overpowered by sink. If you are in high density altitude and able to attain 500-700 feet per minute climb, but encounter 1000 feet per minute sink…. Well it doesn’t take a math wise to figure out what will happen if you stay there.

If you find the ridge lift on one side of a canyon, the sink will usually be on the other side. If you know the direction the wind is coming from, you can visualize the lift and sink. The sink will be on the upwind side and the lift will be on the downwind side.

So what happens in the unfortunate event that we go past the point of no return without executing a turn to lower terrain and suddenly realize that we are going to impact the ground?

We must continue to fly the airplane and maintain control. We must resist the desire and impulse to pull back on the stick to avoid the rapidly rising terrain because that will lead to a stall and the outcome will be much worse, probably fatal. The human body is able to withstand something like 40Gs of lateral (horizontal) force but can only tolerate about 8Gs of compression (vertical) force.

We must attempt to have as normal of a landing attitude as possible to avoid stalling and falling instead of going in while the wings are still producing lift. It is really difficult to push the stick forward, lowering the nose to maintain airspeed, when there are rocks and trees ahead. Done properly, with airspeed control, the straight-ahead landing into rough terrain will probably result substantial damage to or destroying the airplane, but we will have a much better chance of survival and minimal injury.

A forced landing while approaching up slope terrain requires additional airspeed that will allow a transition from gliding to an attitude that parallels the terrain. There needs to be enough airspeed after the transition to safely flare the airplane without stalling.  There is not much time in these situations to analyze and think about what is about to happen. That is why we need to be thinking about it all the time when flying in the back country.

Too often, instead of landing straight ahead into hostile terrain, the pilot will try to turn around. If you don’t have sufficient engine power or room to make a box canyon turn, this is a big mistake. Often the pilot will try to hurry the turn with too much bottom rudder resulting in entering a tuck-under spin where the nose drops rapidly. Even if you know this is coming, it doesn’t matter how good you are or think you are, it is impossible to recover without losing about 400 feet of altitude using normal spin recovery technique.

One of the many FAA “alphabet” terms we are probably all familiar with is CFIT or “Controlled Flight Into Terrain”. It is a special emphasis item for flight instructors. I completed a CFI renewal class recently and the class instructor showed us videos and still pictures of the results of CFIT accidents. It can happen anywhere the terrain is rising and not just in higher altitude areas of the country. Any CFIT accident can be avoided if we realize the limitations of our airplanes and piloting skills and also realize what is happening before we get to the point of no-return.  We need to learn how to recognize this situation and act quickly to turn around before it is too late. That’s one of many new skills and awareness of mountain flying that I mentioned at the beginning of this article.

I have included a link to a YouTube video of an actual accident filmed from inside the cockpit. It was fatal and the footage was found three years after the crash took place in a mountainous area of Colorado. The flight took place in August of 1984 between Granby and Jeffco, CO. The wreckage was discovered in August of 1987 near Tabernash, CO. Caution: It is disturbing to watch. In the first few seconds of the video, the aircraft appears to be well above the terrain, then makes a turn to the right and begins to descend. The stall warning comes on just before impact with the trees. A voice can be heard saying “hold on”. Just as the video ends, it appears that the airplane rolls inverted as it impacts the trees.

http://www.youtube.com/watch?v=ZfPr_gZzHRw&feature=related

This should never become an issue if we establish some conditioning and maintain that programming to always be looking for an “out” to safely get us to lower terrain. Conditioning takes time and in this case it takes “seat time”. If you don’t live close to mountainous terrain, it becomes more difficult to obtain. You can’t really simulate what it’s like is to fly in the back country of Idaho if you live and are flying in the Midwest.

If you still want to fly in Idaho or other back country areas, you should take the time and invest the money to go through a good mountain flying course like the ones offered in McCall, Idaho.

See the link: http://www.mountaincanyonflying.com/

To summarize, when flying in the mountains or back country:

● Always have an escape route in mind and be in a position to execute that option.

● Constantly evaluate where you are and decide if you can lose altitude prior to having to turn the airplane. If not, you don’t have many options available.

● Never fly beyond the turn-around point.

● Stay in a position to turn to lower terrain.

● Always turn away from the terrain.

 

Alan Negrin is CFI,MEI and former factory demo, flight test and transition training pilot. He owns a Sportsman tail dragger and provides transition training for Glasair, GlaStar and Sportsman owners, including those who are about to commit first flight and those who have purchased flying aircraft.

He can be reached at alan@glasairtraining.com or 425-466-8472