Soon after a heavily loaded US Airways Express Flight 5481 crashed in Charlotte shortly after takeoff, airline maintenance appeared as a likely cause.

A mechanic at a small West Virginia repair station had recently adjusted the plane’s elevator control cables, a job he had never done on a Beech 1900B. His instructor was also his inspector. He and other mechanics worked nights; the manager usually worked days. And the FAA officer in charge of monitoring the site had visited only once since mechanics began working there.

The Charlotte Observer set out to find how the Jan. 852003, crash that killed all 21 aboard fit with industry trends. A four-part series Dec. 7~10 reported that airlines are spending less to maintain their planes. Mechanics are checking them less often. Federal oversight is stretched thin. And maintenance is increasingly a factor in fatai crashes.

The Observer found that since 1994, maintenance problems have contributed to 42 percent of fatal airline accidents in the U.S., up from 16 percent the previous decade. Faulty maintenance contributed to three of the past five fatal airline crashes in the U.S., and likely played a role in a fourth, now under investigation.

Airlines have invested millions to fix other serious problems such as pilot error, and overall, crashes are declining. But faulty maintenance, an equally preventabie problem, has never received the attention it deserves, experts told the newspaper.

Sources of data for the series included:
– National Transportation SafetyBoard accidents. This relational database, available for download in Microsoft Access format or for online query from the NTSB, includes facts about crashes, the planes involved, events and contributing factors. At the time of our use, the database held details on more than 50,000 events; it’s updated It was the primary source for statements about accident trends.

We started with a list of US. fatal air carrier accidents since 1994 in which the aircraft was substantially damaged or destroyed. An intranet application built using Active Server Pages/ and Microsoft SQL Server allowed reporters to browse the list, filter it with a Structured Query Language “Where” statement, follow a link to investigative reports, as well as add and edit crash entries. The additions were for new crashes.

The air accident data is referred to as ADMSPUB data and documentation can be downloaded at ntsb.gov/ntsb/quenxasp. The documentation is key to understanding and using the relationships among accidents, aircraft, people, events and contributing factors. Staff in the NTSB Public Inquiries branch answered almost all data questions.
– PTRS inspections. The Program Tracking and Reporting  manages information about inspections of contract repair stations and nonmajor airlines, and a portion of inspections of the nation’s major carriers. It was obtained through a Freedom of Information Act request. The data was provided in yearly text data flies, sometimes covering more than a million inspections. Whiie the data structure was documented, the challenge was to learn how the inspection data was created and used so we could formulate queries. We focused on more than 450,000 closed, completed airworthiness and avionics inspections from 2000 to mid-2003. An inspection was considered to have an unfavorable result if the inspector reported that it led to an enforcement investigation or required follow-up action.

Valuable information about PTRS can be gleaned from watchdog reports issued by agencies such as the General Accounting Office. For example, in 1998 the GAO reported that PTRS records understate the incidence of problems and violations. The Observer obtained an unpublished memo that described in detail the methods and confirmed ours.

Key questions about PTRS were answered by interviewing inspectors and others in the FAA who use the system and its data.
– EIS. The Enforcement Information System data is the record of its actions against people and organizations in aviation. Current data used to be available online. Its distribution was limited and some key Web pages removed following the 9/11 terrorist attacks. An extract of the data became available again in mid-2003. The IRE and Database Library makes the EIS available to journalists. For more information see nicar. org/data/faae.
– TranStats. This online service by the Bureau of TranSportation Statistics provides data on airline spending, including maintenance spending, departures and passengers. It’s available at www.transtats.bts.gov.
– Other data. Several other databases were used in background. These included FAA Accidents and Incidents Database, System Difficulty Reports and lists of contract repair stations. These and other databases are listed on the Aviation Data Systems (AFB-620) Web page at http://afs600. faa.gov/A F8620. htm.

You can read the stories on the Web at www.charlotte.com/mld/charlotte/news/special_packages/planes, and an archive of the newspaper pages in Adobe Portable Document File format is at http://161.188.204.190/charlotte/air

Contact Ted Mellnik by e-mail at tmellnik@charlotte/air.