Tuesday, October 25, 2011
Angle Of The Wing
Angle-of-attack indicators, coming to a glass panel near you
The AOA indicator (or in this case a Lift Reserve Indicator, same instrument, different name) was a tiny, two-inch gauge tucked away on the far-right panel—and it looked to be the oldest instrument in the airplane, a tired, circular gauge with an area marked in faded red, presumably meaning, "Danger, Will Robinson," a small, yellow/white region in the center and the main space marked in green.
To be honest, I wasn't impressed with AOA on my two-day trip across the country to California. I wasn't flying the V-tail anywhere near the bottom of the envelope, where an AOA does its best work. (A few years later, I was again faced with an AOA, this time on a new 36 Bonanza headed across the Atlantic and Mediterranean to Israel. I came to know it slightly better and gained a greater appreciation for its several talents.)
The state of the angle-of-attack art has come a long way since then. The instruments have improved dramatically, and AOA devices of all descriptions have become more and more common on the aftermarket.
Mark Korin of Alpha Systems (www.alphasystemsaoa.com) in Ramsey, Minn., has long been an evangelist for angle-of-attack indicators, not just because his company makes some of the best systems on the market, but because he's convinced the devices could help reduce the incidence of stall-spin accidents.
As Korin will be happy to explain to anyone willing to listen, tracking angle of attack is a far superior method of measuring proximity to a stall than is an airspeed indicator. We're all introduced to airspeed indicators as student pilots, but what we're sometimes not told is that, perhaps ironically, ASIs are least accurate in the range where they're needed most.
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Labels: Accident Statistics, Angle of Attack, Decision Making, Features, Flight Training, Navigation, Pilot Skills, Safety, Pilot Safety