Mountain flying

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What's the big deal about mountains?

Some of the most beautiful and remote backcountry destinations lie within the mountains, and negotiation of this often generalized terrain feature in light aircraft can prove to be a challenge due primarily to the the less dense air of higher elevations, and weather.

Mountains come in all shapes and sizes, and can present the following concerns to a varying degree. But they all represent the same challenge to light aircraft: They are an obstacle that forces pilots to either 1) fly higher to avoid flying "within them," or 2) fly within them. Is flying within mountains a bad thing? No! It is amazing! That's where some of the best and most beautiful flying can be had, and where some of the world's most scenic and remote airstrips exist. However, operating within the mountains significantly changes the game in a few ways:

  • Operating in mountains goes hand in hand with higher altitudes, which can negatively affect the performance of aircraft engines, require higher groundspeed, and possibly have physiological effects on the human body from reduced oxygen.
  • Closer proximity to terrain is often required, and this is often made riskier by any significant wind and weather.
  • Mountains often act as a catalyst for precipitative weather events. They stick up into the atmosphere and cause moisture-rich air masses to lift up into the colder altitudes, condensing their water vapor into rain or snow. If ceilings are too low, there's no flyable space between the ground and the ceiling. Mountains sort of eat that available altitude up just by virture of being high elevation.
  • Mountains introduce drag to winds, causing that wind to become dirty, swirling, oscillatory, and rotor-like in nature. This is called mechanical turbulence and can easily overcome the ability of a light aircraft to maneuver or maintain a safe altitude above the ground.

Obviously this is a rich topic, and several books have been written about it. Two of the best-selling books, "Flying the Mountains" by Fletcher Anderson, and "Mountain Flying Bible" by Sparky Imeson, are very complete guides on the subject. However, mountain flying is simply one of those things that must be experienced in a dual-instruction scenario in addition to studying the more academic aspects. There are elements of the training that just can't be conveyed in a text. Please use this guide simply as a jumping-off point and seek out additional reading. And by all means, get qualified dual instruction.

Mountain flyingSqueaking through a pass in the Lick Creek Range, Idaho. Photo: Richard Holm

Effects of altitude

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Negotiating terrain

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Mountain weather

Mountains often act as a catalyst for precipitative weather events. They stick up into the atmosphere like a giant ramp and cause moisture-rich air masses to be lifted up into the colder altitudes, condensing their water vapor into rain or snow. If ceilings are too low, there's no flyable space between the ground and the ceiling. Mountains sort of eat that available altitude up just by virture of being high elevation.

Wind and mechanical turbulence

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Classic accident scenarios

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List of references

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Disclaimer

While this knowledge base is a compilation of information from various sources, some official in nature, it is not a recognized or acredited source of aviation training information, and thus should be considered entertainment. Please consult a FAA-certificated flight instructor or mechanic prior to putting any information found here into practice.