Flying on a mountaintop is one of the most awe-inspiring and thrilling moments I have ever experienced. The amazement at the huge and beautiful landscape, and the thrill of flying far below you make for a wonderful and enjoyable experience.
I live in Portoviejo, Ecuador, which is a small town 45 minutes from the coast. However this week I managed to get a small trip to Riobamba, Ecuador. After traveling by bus for 8½ hours, I finally arrived at the town, located up in the mountainous ridge going along South America. Riobamba is very close to the Chimborazo Mountain – the highest peak on the planet, but measuring from the center of the earth instead of the sea level. In other words, Chimborazo is the closest point to the sun.
The town is at almost 10 000 feet (3 000 meters) above sea level. The thin air at that altitude makes it harder to catch your breath after making physical exercise. Oh, did I mention that thin air increases airplane stalling tendencies? Both real and model airplanes suffer from this – fly too slow, and you’ll stall!
I have flown my Bixler through 5 batteries in the two days I've been here! And fortunately I have not wrecked it more than a loose aileron horn or a popped off cockpit. In the little flying time I've got, I've learned some things that I would like to share.
Up in the mountains there are plenty of beautiful places. Especially if it’s sunny, the colors of the landscape shine very brightly. Rifts, ridges, mountaintops, tree patches, all combine for wonderful flying experiences.
The terrain can affect the flying conditions. Mountains with rifts and ridges will generally have turbulence in the air, but they provide a much more exciting experience.
One of the biggest issues with flying in high altitude (my experience ranges from 10 000 to 12 500 feet (3000 to 3800 meters) above sea level) is that the air gets thinner – less dense air, lower pressure, lower oxygen levels. Because of this, altitude has effects both on the airplane and the pilot. As for the pilot, lower concentration of oxygen in the air can have a temporary negative effect on the brain. A reduced oxygen supply to the brain can give you a headache, difficulty concentrating, and fatigue. Flying may agitate some individuals, and the thinner air makes it hard to catch your breath.
As for the plane, the altitude increases the difficulty of flying as stall tendencies increase proportionally with the elevation. Stronger stalling tendencies make turning around by banking and yanking much more difficult. But even in straight forward flight, you need to keep up quite some speed to keep from stalling and crashing.
Altitude may also have an effect on the power system. As the air is thinner, the prop can spin around much more easily, reducing the amp draw on the motor, but also reducing the thrust. Theoretically, the best prop at high altitude might make the plane over propped at sea level. Fast altitude changes can affect your batteries! Mine puffed slightly because of the air pressure change.
Altitude can even affect the landscape. Above certain altitude, there are no evil trees!
Wind can be your friend – and your enemy. The highest wind we've had was around 15 – 20 mph. When you’re flying on a mountain with wind,remember that the wind will go up on one side, and down on the other. You definitely want to fly on the side with the wind going up.
A mountain is an unending slope - slope soaring just got beat! Slope soaring usually has a sink area, then a lift area, then another sink area. But on a mountain, lift (as long as you don’t go over the top) it’s just lift, lift, lift! Even a few hundred feet above the ground you can still have enough lift to stay there forever!
Wind on a mountain also has its drawbacks – if there is a rift going down the mountain, there can be a big sink area around it. General rule, the wind will tend to roughly follow the profile of the landscape.
As always, when flying in the wind, you’ll always want to turn into the wind. Turning with the wind will quickly take your plane faraway!
Usually, high places are always cold. And low temperatures can have a slight influence both on the pilot and the plane. For the pilot,cold weather has obvious effects. Numb fingers, trembling (which causes lack of precision), or even cold-related health problems.
The effect of the cold on RC airplanes is less obvious. The cold affects the batteries’ properties. The discharge capacity of a battery goes down as the temperature falls.
Up in the mountains, you will have tons of space to fly – if you stand on a mountaintop, you’ll be able to fly all around even below you! It’s really amazing to stand near the mountaintop and fly the plane down in the valley below. Something I found great was that if you launch from the edge of a cliff, you can have much more time to adjust your trims as you are further away from the ground.With more space to fly, comes less space to land. Especially on a mountain, there are hardly any flat spots to land. If you have to land on a slope, keep in mind that if you go down the mountain into the wind, you’ll have way too much lift to let you touch down. If you go up the mountain with the wind, you’ll be going too fast to be able to land softly. Landing sideways is an option only if you’re good at it. So before you launch your plane, be sure to know where you can land it.
Mountain flying cannot be done with all planes. You need a plane that has a low wing loading, but is still heavy enough to cut through the wind. You also need a lot of power on it so you can climb back to the top. Don’t fly the battery to the end, you don’t want to go down a huge mountain to get your plane back! Use a plane that can land on rough terrain or tall grass.Belly landings are really good for tall grass.If you ask for a specific recommendation, I can’t recommend the HobbyKing Bixler enough! Just put clear tape on the belly and the nose and the leading edges, and it can take a really hard beating! Use a 2200mAh; battery instead of the recommended 1300mAh, the bigger battery will give you about half an hour of enjoyable cruising. However, if you plan to do fast dives and high G maneuvers, you will need to reinforce it a bit more.
Mountain flying is a really enjoyable activity – but it’snot for the faint of heart or for beginner flyers. Get a good plane, find a nice spot, and enjoy yourself more than ever before. Prepare for an adrenaline-filled experience when your plane makes a close pass on a ridge!
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