AIRCRAFT ACCIDENT RATES

The transport of radioactive materials occurs through various transportation modes such as air, sea, road and rail. The design and performance standards for all these transport modes have been same up until the IAEA Regulations for the Safe Transport of Radioactive Material were published in 1996. These regulations introduced a new more robust package type, named as “Type C” package, with enhanced design and performance standards required for shipments of large quantity of radioactivity material by air. In 1998, the IAEA sponsored a coordinated research project (CRP) on Accident Severity during Air Transport of Radioactive Material, in order to investigate the effectiveness of the regulatory requirements for the air mode of transport. One of the tasks of this project was to collect and review the data on air accident rates for the purposes of analyzing the pertinent information on frequency and severity of air accidents related to the challenges of impact, fire and immersion posed to a package in severe air accidents. Aircraft accident data that were considered in the CRP are those involving commercial aircrafts which occurred from 1990 to 2000 with certified take-off weight more than 27,000 kg. This paper presents the aircraft accident rates data used in the CRP and further updated to 2006, covering world wide operations for both passenger and cargo operations. The analysis presented in the paper is based on the accident data obtained from International Civil Aviation Organization (ICAO) Accident Incident Data Reporting (ADREP) system. The scope of the paper is broader than the CRP and covers aircraft with a maximum certified take-off weight greater than 2,250 kg that were either considered destroyed aircraft and/or were involved in fatal accidents that occurred until 2006. In order to factor the increase in aviation activities over the years, the data also gives the total number of departures in a particular year by regions and calculates the rate of destroyed aircraft (number of aircraft destroyed per 1 million flights), passenger fatality rate and rate of accidents with passenger fatalities for both passenger and cargo operations. The paper shows that there has been an almost steady drop in air accidents over the years and consequently the assumptions made in the Air CRP about the rate of air accidents remain valid and conservative in respect to the updated information until the year 2006.