Even before two crashes in less than one week killed 47 people, statistics showed that Compañia Cubana de Aviacion is one of the most unsafe airlines in the world.

A continuously updated statistical study shows that Cuba's government-owned airline is the only one in the world that suffered more than one disaster this year. On Dec. 21, the runway crash of a Cubana-leased DC-10 in Guatemala City killed 25 people; and Saturday's crash of a Russian-built Yak-42 near Valencia, Venezuela, killed 22. Those crashes brought the number of Cubana disasters since 1970 to eight; one of them was the result of sabotage.

The study is compiled by Todd Curtis, a safety engineer for Boeing Co. who runs a private Web site, AirSafe.com. Boeing has no connection with the site.

Curtis rates airlines on the number of ``fatal events'' per number of flights. By that standard, Cubana has a ``fatal event rate'' of 24. It is followed by AeroPeru, with a rate of 16.7; Air Zimbabwe, 12.5; China Airlines of Taiwan, 10; Royal Jordanian Airline, 8.82; Transportes Aereos Regionais of Brazil, 8.33; and EgyptAir, 8.

Employees of Cubana and of Cuba's civil aviation agency referred questions about the company's safety record to the carrier's vice president, Heriberto Prieto Musa. When first contacted Monday, his assistant said he was in a meeting. Later, his office phone rang unanswered.

Cubana would not lead the unsafe list if the former Soviet Republics and China provided data on the number of flights their airlines operate. These airlines far exceeded Cubana and every other airline in the number of fatal accidents. Soviet and post-Soviet airlines had 17; Chinese companies had 14 since 1970.

The Cubana safety record has been a source of concern for former employees for years. ``They often take off without meeting all safety regulations, because they don't have spares in stock to change parts,'' Carlos Mujica Otero, who worked for Cubana, told radio station WQBA in 1997.

All but two of Cubana's eight disasters occurred with Soviet-made planes, which make up the bulk of the airline's 26-plane fleet. The exceptions were the notorious sabotage destruction of a DC-8, killing all 73 people aboard, and the Guatemala crash. The other crashes were:

In 1985, an Ilyushin 18D near Havana, blamed on engine failure; all 41 aboard died.

In 1989, an Ilyushin 62M near Havana; the flight took off in a thunderstorm; all 126 people aboard died.

In 1990, a Yakovlev 40 near Santiago de Cuba, blamed on pilot error; 11 of 31 people aboard died..

In 1997, an Antonov 24 near Santiago, apparently due to engine failure; all 44 aboard died.