The government on Tuesday ordered immediate maintenance checks on 44 Russian-made helicopters operating in the country, after critical problems were found in a sampling of engines.

The helicopters to be checked are the Ka-32s in service with 11 government agencies such as the Korea Forest Service, the Coast Guard and regional administrations, the Ministry of Land, Infrastructure and Transport said.

It said the decision was made after engines in eight of 10 helicopters that underwent checkups recently were found to have mechanical problems.

"There had been two internal engine explosions while the choppers were on the ground that led to very detailed inspections being conducted, and this in turn led to the discovery of problems in the compressor turbine sensors as well as rotor blade turbines," the ministry said

The Ka-32s were brought into the country as part of the Brown Bear project that called for Moscow to pay back loans provided by Seoul to the former Soviet Union in 1991. Russia, short of cash at the time, sent military equipment such as choppers, tanks and armored fighting vehicles to South Korea. The helicopters were made by Kumertau Aviation Production Enterprise and built between Sept. 1986 and Dec. 2009.

It said that operators of the chopper are required to report measures taken that call for exchange of faulty parts and to check each Ka-32 after every 50 hours of flight.

In addition, Seoul will inform Russia of its findings so it too can check the safety of the rotary aircraft and take necessary measures. (Yonhap)