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Tehachapi Skywatch
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Posted by editor Tue Nov 30, 1999 00:00:00 PST
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0 responses 0 comments A few weeks ago another small plane went down with the loss of two more souls in the infamous Tehachapi Triangle. Other articles have covered that tragedy, and far be it from me to make any judgments before the investigation is complete. I just want to touch on the issues that lead to more than our share of general aviation accidents.

The Tehachapi Triangle is the area between Gorman, Bakersfield, and Mojave. This encompasses most of the Tehachapi Mountain Range and the Tehachapi Valley. According to one source, there have been nineteen accidents in the last fifteen years within that area. Our local aviators are well aware that they operate in an area plagued with potential dangers. However, those who don't fly are probably not aware of the challenges we face here.

The mountains. That hazard seems obvious enough. I don't have the statistics, but I'm willing to bet that most of the accidents around here are what we call “controlled flight into terrain;” otherwise known as “flying into a cumulo-granite cloud.” While our valley is four thousand feet above sea level, the surrounding mountains rise another four thousand feet above the valley. 

Poor aircraft performance. Unless an aircraft has turbo or supercharged engines, an aircraft trying to climb in the Tehachapi Valley has a much tougher time than at sea level. Visitors who do not factor this in can find themselves flying too low with too little power available.

Poor weather. As air masses climb over the Tehachapi Mountains, they cool and accelerate, causing cloudiness, haziness, high winds, and turbulence. Pilots must be very knowledgeable about weather, including the factors unique to mountain flying.

Icing. All clouds are made of moisture. High clouds are colder than low clouds. If the temperature of the moisture in the clouds is below freezing, is can create ice on an aircraft. Aircraft performance is greatly reduced on an iced aircraft. Not only does the ice add unexpected weight to the aircraft, it changes the shape of the wings making them unable to generate enough lift. If an aircraft climbs to go over mountains and flies into freezing clouds or freezing rain, ice will form on the aircraft. If the aircraft doesn't have deicing equipment, slowly but surely, the aircraft starts to descend. If you don't get rid of the ice before you clear the mountains, you're going to have to land – one way or another. (Rest assured:  All airliners have deicing equipment; however, most light aircraft are not so equipped.)

Military airspace. Military airspace surrounds and lies over the Tehachapi Valley. Even with today's radars, transponders and radios, the primary means of collision avoidance is still “see and avoid” using the “Mark 1 eyeball.” Unfortunately, military aircraft do everything possible to defeat the Mark 1 eyeball! Further, they don't use the same radio frequencies or controllers that we do.  While close encounters with military traffic are infrequent, the need to watch for them creates yet another layer of mental burden for pilots.

Mixed traffic. Tehachapi has two airports - one primarily for gliders and one primarily for airplanes - and they're only a couple of miles apart. Add to that the fact that most gliders don't have radios, most transiting pilots probably aren't thinking about gliders, and throw in a few helicopters trying to fight wildfires, military training aircraft, ultralights, hang gliders; and you have some fairly complicated airspace to contend with.

So the next time you see a small airplane cruising around the valley, realize that these are very bold people with a lot of training and a lot on their plate, while still trying to enjoy the magic of flight.

Manned Space Watch - Atlantis still under repair while Expedition 15 takes over
Space Shuttle Atlantis, after sticking her nose out around the corner looking for any mischievous hail-laden thunderstorms lurking about, confidently lumbered from the Vehicle Assembly Building to venerable launch pad 39A. She spent three months undergoing repairs to hail damage. (Maybe NASA needs to take out hail insurance like the farmers do.) She stands poised for launch to Space Station Alpha on Friday, June 8 at 4:37 p.m., Tehachapi Time, where she will install a second starboard truss segment and a third set of solar arrays and batteries. This is the Space Shuttle Program's 21st mission to the International Space Station.

Night Sky Watch
The moon will rise later each night this week with mostly clear skies and warm temperatures – just right for stargazing!

Venus is still dazzling, though it will now start moving closer to the sun (angle-wise). No one has yet reported seeing it before sunset. There's still a drink coming to the first reader to report seeing Venus in broad daylight! Let me know at hawk@ieee.org.

Saturn is high overhead at sundown. Jupiter reaches opposition this week, rising around midnight.

Sunrise/Sunset (PDT)
5:39 a.m./8:06 p.m.

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