The Liberty Gazette
August 12, 2008
August 12, 2008
The View From Up Here
By Mike Ely and Linda Street Ely
Mike: When bad things happen in aviation it usually makes news in a big way. Statistically, aviation accidents don’t happen often. Commercial airline flight is the safest mode of transportation. General aviation flies almost two-thirds of all (U.S.) flight hours and reports a better safety record than most other modes of transportation, even the family car. Hence, the saying, “the most dangerous thing about flying is driving to the airport.”
When the NTSB (National Transportation Safety Board) investigates an accident, their first priority is gathering facts. Just as the DPS secures a fatal accident scene, takes measurements and collects witness reports, so does the NTSB. Information is collected on pilots, passengers, aircraft records, and reports from witnesses. A preliminary accident report is published while the investigation continues. As officials sift through information a chain of events emerges, the “error chain,” which tells the story of how the accident happened.
Pilots may take advantage of recurrent training and free FAA accident prevention safety seminars to identify and break the “links” in an error chain. Break the chain and the accident doesn’t happen. What makes the news is that small percentage of error chains that wasn’t identified and broken, while the huge success rate goes unnoticed because the aircraft didn’t crash, and thus was not a newsworthy item.
Linda: Not long ago across the page from us Kevin Ladd ran a series of genealogy terms. Maybe we should have a word of the week, because some aviation terms need explaining. For instance, “Stall.” When your car stalls that means the engine stops. In aviation-speak it has nothing to do with engines; it’s the aerodynamic stall of the wing. A simplified explanation: the wing creates lift, overcoming the weight of the airplane by means of airflow over and under the wing. Pitch up at an angle that maximizes lift, and it flies. Too much pitch, not enough speed, airflow over the top of the wing will begin to separate.
Mike: As it separates the air “burbles” in swirls and eddies like water in a brook around rocks, starting at the aft edge of the wing first, creeping forward as the angle of attack is increased. With the separation of airflow comes the loss of lift. Eventually the loss of lift is so great the wing is considered aerodynamically “stalled” and plane stops flying. The engine may be running just fine. Pitch down with the nose and add power to recover from a stall. When an engine quits it’s called an engine failure, or “flameout” in jets. In that case, if a re-start is unsuccessful, the airplane becomes a glider and can be flown to a safe landing.
Considering risks each time we fly, we take measures to reduce and manage them as much as possible to the point where each flight, while adventurous, fun, and educational, is a non-newsworthy event.
Linda: Speaking of adventurous our buddy, John Smutny, was busy organizing and running the World Aerobatic Championships, held in the U.S. this year, in Pendleton, Oregon. John told us that as one of the Directors, he’s spent the past 18 months arranging for the aerobatic training boxes at various airports in the area, setting up an International Village to host the competitor teams, and serving as Air Show Boss for last Sunday’s air show. I’ll be interested to see how young Brian Dierks fared, since we enjoyed watching him practice in his Sukhoi SU-29 in Giddings back in May. I think its time for me to do some more aerobatic training.
Mike and Linda can be reached at Texasavi8r@aol.com.