The Liberty Gazette
April 2, 2013
Ely Air LinesBy Mike Ely and Linda Street-Ely
Linda: Lots of folks are asking these days whether airplanes can land at airports where a control tower has been closed, and if so, how that works. We’re happy to explain, but first understand that closed towers do not cause airplanes to fall out of the sky. There’s that thing about lift that keeps airplanes in the air and it doesn’t depend upon air traffic control towers, not one little bit.
That reminds me of a saying in aviation: If you’re making an emergency landing remember Bernoulli, not Marconi. Daniel Bernoulli and Giovanni Venturi taught us about fluid dynamics and how low pressure creates lift – flight. If you move your focus to the great invention of Guglielmo Marconi, radio calls to someone on the ground won’t get you there safely. First, one must fly the plane.
21-year-old Sarah Rovner did that only three months after receiving her private pilot license. The engine in the Cessna she was flying quit and she made headlines last year with her safe landing on Davis Street in Conroe. That’s because she kept her attention on flying the plane. Communication at that point was secondary, which brings us back to air traffic control towers and their role in safe air travel.
Sarah was planning to land at the Conroe airport when she had no choice but to land the airplane on Davis Street. She did a fine job and there were no injuries. If she had been able to make it to the runway she would have received a clearance to land that would have sounded something like this: "Cessna One-Two-Three-Four-Five, wind one-seven-zero at four knots, cleared to land Runway One-Niner." But if the tower had been closed (which it does nightly at 10:00 pm.) Sarah would have followed traffic rules that apply when landing at an airport with no tower, such as Liberty’s.
Mike: The standard traffic pattern is a well laid plan which provides for predictable behavior for all airplanes approaching a given airfield.
First, a pilot plans to land into the wind as close as possible. Since the wind doesn’t always line up perfectly with runways sometimes there’s a cross wind, but the goal is to pick the direction for landing that puts the airplane as much into the wind as possible. Determining that direction will dictate how to enter the traffic pattern. Imagine a rectangle, the runway being one of the long sides. The other long side is called the "downwind" side. To enter a standard pattern one would fly at a 45-degree angle to the downwind leg and then reaching about half a mile from the runway would turn exactly parallel to the runway in the opposite direction they will be facing when landing. The airplane would then fly a rectangle-shaped pattern so that when turning final there is enough room to finish descending to the runway, into the wind.
Standards let people know what to expect. Obviously knowing the wind direction is essential to picking the right runway. For that reason, airliners flying into airports without control towers (which they already do), must be able to receive weather reports from that airport. And while radios are optional at most airports, they are certainly a good idea so that other pilots in a traffic pattern can be heard making position announcements.
While air travel may slow during this political insanity, airplanes can still land at non-towered airports. It’s done every day right here in Liberty.
www.ElyAirLines.blogspot.com
No comments:
Post a Comment