Aviation Safety Letter 1/1998
Mountain Flying — Part II
by Pat Very
There are countless combinations of routes throughout the mountains and picking the right one for you, your aircraft and your load comes with practice. The best way to learn about mountain flying is to fly in the mountains. With every flight, you will become more comfortable and knowledgeable.
Always monitor 126.7 MHz en route and request station updates when within range of an FSS. The radio operators are real professionals and are the backbone of the system. Try to confine your requests to the last 50 min. of the hour; the operators will be forever grateful for the time to get the hourly observations out on the computer for the rest of us.
Generally speaking, I like to travel as high as possible, consistent with comfort, and regularly fly at 10,000 to 12,000 ft. when crossing the rocks in VFR flight. Altitude has a number of advantages. Quite often, flying at 10,000 to 12,000 ft. will put you above scattered to broken cumulus and towering cumulus and, therefore, give you a smoother ride, lessening fatigue from turbulence. Altitude also will give you better radio reception for amendments and updates, as well as a larger spectrum from which to navigate. Then, of course, there is the old engine-failure scenario! Wouldn’t it be nice to be high if that ever happened, especially in the mountains? With the advent of LORAN and GPS, it's easy to set out blindly across the rocks, oblivious to the consequences. Knowing where you are at all times and how far it is to the nearest airport, settlement or road is a must.
Approach pass summits and ridges in level flight. The clearance required will be determined by the wind direction, velocity and cloud base. Again, look for clues — ridge plumes, cumulus, bear paws, bending trees, wind on the water, and so on — and check your vertical speed indicator and altimeter. Under no circumstances should you still be climbing for this clearance altitude when arriving at the summit or ridge. If you have to turn around, make your decision early while there is still plenty of room. By the way, don't even think about penetrating cloud; it's the quickest way that I know of to become a statistic.
Watch out for the shadowed valley sides in the late afternoon: under certain conditions, they can all but disappear, leaving you with a dangerous guessing game. If you feel uncomfortable and conditions allow, climb for better reference.
On the bright side, generally speaking and owing to prominent landmarks, map reading tends to be easier in the mountains than on flat land.
For those of you with really light aircraft such as Cubs, Champs, and ultralights, a lift bonus can occasionally be reaped by flying the sunny or downwind side of the valley. Recently, while ferrying a J-3 Cub (without mixture control) through Banff, Alberta, back to Chilliwack, British Columbia, I found myself, owing to a variety of conditions, unable to climb to a safe altitude to clear the pass. After a few unsuccessful attempts, I spied a bright patch of sunshine on a west-facing slope. By positioning my aircraft over the sunny slope, I was able to climb to a sufficient altitude to clear the pass with a degree of comfort and safety.
Dominated by the Pacific with its many currents and weather patterns, the British Columbia coast presents unique challenges to the pilot. It is home to some of the fastest-moving weather on the continent. Conditions can change for the worse with very little warning. With its many channels, straits and fjords, the coast can be transformed by low ceilings into a series of tunnels, many of which have absolutely no flat ground before meeting the sea.
The lower the ceiling, the more the busy traffic is compressed into a smaller area. Under these conditions, be sure to have all lights on, keep a sharp lookout and try to stay to the right. Monitor local stations and transmit your position as you transit the area. Also, be aware of the new CARs requirements for VFR flight in uncontrolled airspace. Operating at or above 1000 ft. AGL requires the following:
- during the day, 1 mi. flight visibility;
- at night, 3 mi. flight visibility; and
- 500 ft. vertically and 2000 ft. horizontally clear of cloud.
Operating below 1000 ft. requires:
- during the day, 2 mi. flight visibility;
- at night, 3 mi. flight visibility; and
- flight clear of cloud.
Be sure to update your weather at every opportunity.
One fall afternoon at my Savary Island cabin just off Powell River on the British Columbia coast, I was standing on the deck listening as the familiar drone of a Beaver approaching the island got louder and louder. The weather was terrible. Low stratus capped the trees and I strained my eyes through the drizzle and fog to catch a glimpse of the aircraft as it passed. My cabin is located about 100 ft. above the sea and 100 yd. inland. As the sound reached its loudest point, I noticed a tail strobe just above the cliff. The rest of the aircraft was below and not visible. I remember thinking to myself at the time, "Better you than me, pal," but, on the coast, life goes on and, most of the time, so does the flying. Sometimes the weather cooperates and it's a pilot’s delight; other times you wish you were home by the fire with a good book. Be cautious on the coast and ask lots of questions.
Mountain strips come in a myriad of sizes and shapes, each with its own idiosyncrasies. Some are one-way, meaning that you land one way and, usually because of terrain, take off in the opposite direction. With many one-way strips, you are committed once on short final. Overshooting would be out of the question because of the climb gradient required to clear terrain. Some are not strips at all, but rather straight stretches of logging roads used by logging companies. You may choose not to land on strips such as these, but keeping a mental picture of their position might come in handy in the event of an emergency. Airports range in height from sea level to as high as 9000 or 10,000 ft. Knowing how to calculate density altitude and how it relates to your aircraft's performance is imperative.
While stationed in Colorado Springs, Colorado, with the military, I had occasion to visit a small town in the mountains called Leadville. It boasts the highest airport on the North American continent at 9969 ft. The density altitude in the summer can reach 13,000 ft. I drove to the airport, more out of curiosity than anything, and spoke with a young instructor working at the flight school. She was teaching in a Cessna 172. When I asked her how she could constantly operate that close to the service ceiling of the aircraft, she replied, "Seems normal to me — I learned to fly here. It's all a state of mind. Besides, everything's downhill from here anyway." I guess the lesson here is that the more familiar you become with something, no matter how unusual, the more comfortable and proficient you become.
Many airstrips, such as those in Pemberton, British Columbia, and Banff, are at the junction of two or more converging valleys. Because each valley can generate its own weather and, therefore, its own wind, it's not unusual to see wind socks at either end blowing in opposite directions. Use extreme caution when operating in windy conditions from these types of strips.
Watch out for strips beneath glaciers and ice fields in the late afternoon. Subsiding cool air known as katabatic wind can cause considerable downdrafts and seriously diminish your aircraft's performance.
A word to the wise: avoid static run-ups on gravel and sand. By holding the controls back and learning to perform run-up and pre-takeoff checks while backtracking, you will save many dollars in propeller repairs. Be ready to go when you reach the end; by stopping, you can lengthen your takeoff roll by as much as 200 ft.
Mountain flying is a rewarding experience. Plan ahead, stay alert to the changing conditions, and enjoy the splendour below. Happy landings!
About the Author
Pat Very is a private pilot with a commercial licence. He started flying in 1970 on the East Coast, but since moving out West in 1978, he has accumulated over 4000 hrs of experience in and around the Rocky Mountains.
Source: Transport Canada Website