Tuesday, September 6, 2011
The Ted Stevens Accident
It looks as if we’ll never know exactly what happened
In 2008, after having tests done to submit to the FAA, the pilot applied again. An April 8, 2008, internal FAA memorandum from the Alaska Regional Flight Surgeon noted the following about the application: “Sixty-year-old airman status post-cerebrovascular accident as noted, now two years out from the incident. No recurrence and neurology report entirely normal. OK to issue with warning.”
The Alaska Regional Flight Surgeon’s office sent the pilot a letter dated April 9, 2008, stating the following: “[Y]ou are eligible for a first-class medical certificate.… Because of your cerebrovascular accident, operation of aircraft is prohibited at any time new symptoms or adverse changes occur.”
All of the surviving passengers had flown with the accident pilot on previous flights, and none reported anything different about his behavior on the day of the accident. The passenger who was in the third seat behind the pilot on the left side of the airplane stated that the weather conditions during the accident flight weren’t remarkable and didn’t seem “risky” based on his previous experience with general aviation flights in Alaska. He described the conditions as “characteristic” Alaska flying. He stated that all of the flights were made below the cloud ceilings and that the airplane entered the clouds for a few seconds on rare occasions. He described the pilot as prudent, cautious, very quiet and businesslike but not humorless, and he stated that he got the impression that the pilot had “flown the routes so many times that he had memorized them.”
The passenger who was in the right cockpit seat during the accident flight stated that the pilot seemed alert, and that he didn’t see the pilot do any paperwork during the flight before the passenger fell asleep.
The airplane had GPS equipment including a terrain warning system, which would have generated audio and on-screen text alerts. Investigators talked with a friend of the pilot, who said when they flew they generally turned off the audio warnings. The airplane also was equipped with a radar altimeter system that would have issued aural and visual altitude alerts about four to six seconds before impact.
The NTSB asked for help from the Armed Forces Institute of Pathology and the Mayo Clinic in reviewing medical records and autopsy reports for evidence that the pilot suffered another stroke or some other incapacitating event. No such evidence could be found.
The NTSB determined that the probable cause of this accident was the pilot’s temporary unresponsiveness for reasons that couldn’t be established from the available information. Contributing to the investigation’s inability to determine exactly what occurred in the final minutes of the flight was the lack of a cockpit recorder system with the ability to capture audio, images and parametric data.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.
Page 3 of 3
Labels: Accident Statistics, Columns, FAA Regulations, Features, NTSB Reports, People and Places, Pilot Skills, Pilot Talk, Proficiency, Pilot Safety