The AirSafe Journal - Issue 9

The AirSafe Journal
Issue 9 - 29 April 1997
Todd Curtis, PhD

This issue of the AirSafe Journal discusses FAA safety data issues, a Pulitzer prize winning series on 737 rudder systems, and a recent report on wildlife strikes to aircraft in the U.S.

Contents

• Pulitzer Prize For 737 Rudder Stories
• FAA Report on the Uses of Aviation Safety Data
• Wildlife Strikes to Aircraft in the U.S.: 1993-1995

Last month, Byron Achohido of the Seattle Times newspaper received a 1997 Pulitzer prize for journalism for a series of stories about suspected rudder problems in the 737. While AirSafe.com will not comment about the substance or the accuracy of this series of articles, we do invite the reader to read Achohido's articles and judge for themselves. The five part Seattle Times series was called "Safety at Issue: The 737".

In January, the FAA published a study entitled "A Report on Issues Related to Public Interest in Aviation Safety Data" which provided a overview of some of the issues involved with making aviation safety data more available and accessible to the general public. The study discussed the insights and findings of researchers both inside and outside of government who looked at how safety data could be used to help consumers compare different U.S. airlines. One key finding was that there is no real difference in the safety records of different airlines that are in a similar class. For example, there is no statistically significant difference between the accident records of major U.S. air carriers. Another interesting finding is from Professor Arnold Barnett of the Massachusetts Institute of Technology who showed that from the beginning of 1990 to the first quarter of 1996, that there is a negative correlation between an airline's incident rate and accident rate. While the result did not prove that a negative relationship exists, it serves to point out that non-accident airline safety data may not be a good predictor of future accident rates.

Another point brought up in the report was that the FAA does not routinely report safety data for individual carriers. This was illustrated in a very obvious way within the report. Exhibit 1 of the report was adapted from a 1994 Barnett paper and showed that when eight major U.S. carriers were ranked by death risk, that the rankings radically changed between three consecutive 10 year periods. In the FAA report, the airlines were identified only by letter, but in the original Barnett paper, the airlines were identified by name. It is rather curious that the FAA would choose to obscure the identity of these airlines when that information is already freely available to the public.

The study raised a number of important issues and also provides a list of references dealing with other aspects of aviation safety data. I would encourage interested readers to read the entire document and come to their own conclusions.

For those of you who have visited my Bird Hazards to Aircraft section at http://airsafe.com/birds.htm, you are probably aware that bird strikes have led to several serious accidents with large jet transports since 1975. The FAA recently released the study Wildlife Strikes to Aircraft in the U.S.: 1993-1995 which details the extent of the threat that birds and other wildlife pose to U.S. aviation. The document contains a wealth of information in charts and graphs, including a breakdown of bird strikes by altitude and size of bird. If you are interested in the subject, please visit Bird Strike Committee USA at www.birdstrike.org

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