Concerns on Boeing 777's safety grow

Above is Boeing 777, the type that crashed in San Francisco, Saturday. / Korea Times file

By Nam Hyun-woo

The Asiana Airlines Boeing 777's crash landing at San Francisco Airport raised additional concerns about the safety of one of the U.S. plane maker's best sellers.

The Boeing 777, known as the "Triple Seven" within the industry, is one of the most modern passenger jets, first introduced in 1995.

According to the manufacturer, United Airlines was the first carrier to put a 777 into commercial airline service, and now aircraft has accumulated more than 5 million flights and 18 million flight hours.

The 777 series has several models with different fuselage lengths. The plane which crashed Sunday was a seven-year-old B777-200ER. The airline's website says the jet can carry between 246 to 300 travelers.

The crashed plane had accommodated 291 passengers, including 77 Koreans on board.

The twin-engine wide-body plane is considered one of the safest and most fuel-efficient aircrafts, and will replace older long-distance jets and bridge the capacity gap between the manufacturer's jumbo B747 jets and medium-sized B767s.

The crash on Saturday recorded the first fatalities in the 777's 18 year history.

The same type has been involved in some accidents producing superstructure damage, according to the manufacturer's report.

In January 2008, a British Airways B777-200ER with a Rolls Royce Trent engine crash landed at London's Heathrow airport after flying from Beijing. There were 47 injuries and no fatalities.

After the accident, Boeing found that the fuel-oil heat exchanger was clogged with ice crystals from the fuel system. In 2009, air authorities ordered a redesign of the engine.

The 777 series has suffered a string of engine problems which led to mid-flight engine shut downs.

The latest incident was when a Korean Air jet made an emergency landing at a Russian airfield in Siberia on July 2.

The Ministry of Land, Infrastructure and Transport investigation concluded that one of the two engines of the jet shut down during the July 2 incident. General Electric (GE), the U.S. engine maker, acknowledged a problem with the engine.

The aircraft involved in that incident was a B777-300ER that has a longer range than the 200ER, the type which crashed in San Francisco. The ill-fated aircraft had PW 4090 engines.

There were two other mid-flight engine shut downs on 777 jets powered by the GE engine this year. One was on an Air China airliner in May and the other was on a Russian carrier, Aeroflot flight, in February. In three cases, the planes were able to continue flying using one engine.

GE said on Friday in a statement that "GE is working with Korean Air and Boeing to repair the engine so the aircraft can return to Incheon."

The B777-200ER series, which crashed Sunday, is released in three variants powered by three different engines, Rolls Royce Trent, GE 90 and Pratt & Whitney PW4090.

Pratt & Whitney said in a statement on Sunday that "We are cooperating fully with the investigating authorities, however, we are unable to offer any further comments as the investigation is ongoing."

Asiana Airlines is the second largest carrier in Korea, following national Korean Air. It has 12 B777s powered by the Pratt and Whitney's engines.