If there can be such a thing as a good year for accidents, 2011 was that year in worldwide commercial jet aviation.
The 2011 record showed reductions in two of the most serious accident types, runway excursions and approach and landing accidents. Runway excursions — veer-offs and overruns — occurred in 25 percent of the 36 accidents last year, compared with 33 percent of the 40 accidents in 2010. Approach and landing accidents represented 58 percent of the total in 2011, versus 65 percent the previous year.
Absolute numbers of these types of accidents were lower as well: nine overruns in 2011, 13 in 2010; 21 approach and landing accidents in 2011, 26 in 2010. The data are derived from Boeing Commercial Airplanes’ annual statistical summary.1,2 Airplanes manufactured in the Soviet Union or the Commonwealth of Independent States are excluded for lack of operational data.
Total accident numbers have been declining, down from 62 in 2009. On-board fatalities have dropped as well: 175 last year, compared with 555 in 2010 and 413 in 2009. Fluctuations in annual fatality numbers, however, are partially influenced by chance — an accident involving the same basic aircraft type might kill two people, the pilots, on a cargo flight and several hundred on a passenger flight. One 2011 fatal crash, in fact, did involve a scheduled cargo-carrying Boeing 747-400 that crashed into the sea while the flight crew was diverting because of an on-board fire, with the loss of the two pilots, the only crewmembers.
Four of the 36 accidents in 2011 (11 percent) involved at least one on-board fatality, versus eight of 40 in 2010 (20 percent) and nine of 62 (15 percent) in 2009. Seven of the 2011 accidents (19 percent) were major accidents, according to U.S. National Transportation Safety Board terminology.3 Comparable percentages were 28 percent in 2010 and 21 percent in 2009.
In its accident data, Boeing emphasizes time frames longer than a year. Fatal accidents in passenger operations during the 10-year period 2002–2011 numbered 63. The comparable number for 2001–2010 was 69. On-board fatalities in passenger operations in the most recent 10-year period totaled 4,486; in the previous 10 years, 4,711.
In scheduled passenger service, there were 60 fatal accidents in 2002–2011, compared with 67 in 2001–2010. However, all accidents in passenger operations increased from 308 to 317 in the most recent 10-year period. Accidents in cargo operations decreased from 80 to 74 in the most recent period.
The fatal accident rate in 2002 through 2011 for scheduled commercial passenger operations was 0.34 per million departures, and 0.62 for other types of operations, including chartered passenger, scheduled cargo, chartered cargo and maintenance testing. The equivalent rates for 2001–2010 were 0.40 and 0.67, respectively, for improvements of 15 percent and 7 percent.
The 79 fatal accidents from 2002 through 2011 represented 20 percent of the total accidents. The 87 fatal accidents from 2001 through 2010 were slightly more of the total, at 22 percent. A more striking difference can be seen in comparing the latest 10-year period with the 53-year period that began in 1959, around the beginning of commercial jet aviation. In that span, fatal accidents were 34 percent of the total.
Ideally, design improvements should result in a larger percentage of substantial damage accidents without fatalities. Little change is evident, however. From 2002 through 2011, the rate was 60 percent; from 1959 through 2011, it was 59 percent. The total period includes recent years, so a comparison of the most recent decades with the most distant might tell a different story.
Boeing examined fatal accidents using the standardized taxonomy of the U.S. Commercial Aviation Safety Team/International Civil Aviation Organization (CAST/ICAO).4 For some 10-year periods, “loss of control–in flight” (LOC-I) has resulted in the most fatalities. In the 2002–2011 period, LOC-I fatalities as a percentage of all fatalities were reduced. Among on-board fatalities, 1,493 of a total 4,547, or 33 percent, were in the LOC-I category. In 2001–2010, it had been 1,765 of 4,774, or 37 percent.
The number of fatal LOC-I accidents, 18, was reduced in the most recent period from the previous 20.
Controlled flight into terrain (CFIT) claimed a higher percentage of lives among the total in 2002–2011, 24 percent, compared with 21 percent in the previous 10-year stretch. There was one more CFIT accident in 2002–2011 than in 2001–2010.
Otherwise, there was little change in percentages of on-board fatalities associated with CAST/ICAO categories between the two periods.
Boeing combines the RE category (runway excursion [landing]) with ARC (abnormal runway contact) and USOS (undershoot/overshoot) in the third-greatest source of on-board fatalities. That was involved in 17 percent of fatalities, similar to the previous period’s 16 percent.
Runway excursions on takeoff (RE [takeoff]) accounted for 154 on-board fatalities in 2002–2011,3 percent of the total. That matched the percentage for 2001–2010.
Notes
- Boeing Commercial Airplanes. Statistical Summary of Commercial Jet Airplane Accidents: Worldwide Operations 1959–2011. www.boeing.com/news/techissues/pdf/statsum.pdf.
- The data are limited to commercial jet airplanes over 60,000 lb (27,216 kg) maximum gross weight.
- An airplane accident is defined as “an occurrence associated with the operation of an airplane that takes place between the time any person boards the airplane with the intention of flight and such time as all such persons have disembarked, in which death or serious injury results from being in the airplane; direct contact with the airplane or anything attached thereto, or direct exposure to jet blast; the airplane sustains substantial damage or the airplane is missing or completely inaccessible.” Occurrences involving test flights or hostile action such as sabotage or hijacking are excluded.
- A major accident is defined as one meeting any of three conditions: the airplane was destroyed; there were multiple fatalities; or there was one fatality and the airplane was substantially damaged.
- www.intlaviationstandards.org.