The Civil Aviation Administration of China (CAAC) announced on Feburary 15 that all their airplanes manufactured by McDonnell Douglas (MD) have passed an examination into potential mechanical problems.

Sources with CAAC said all reports from its subordinate airlines which own MD airplanes suggested that all 50 of their MD produced airplanes are in good mechanical condition.

"All those planes prove capable of conducting their aviation work well," the source said.

Last Saturday, following a report that an US Alaska Airline registered MD-80 crashed into the Pacific Ocean due to mechanical problems, CAAC ordered all its subordinate companies to conduct urgent examinations on all MD planes.

CAAC ordered those companies to hand out their examination results before noon yesterday.

All the domestic MD airplanes are now operated by China Eastern Airlines and China Northern Airlines, based in Shanghai and Shenyang respectively.

The stress of this examination is the balance systems or horizontal stabilizer of MD made airplanes.

If a plane loses its horizontal stabilizer, it will be unable to keep its nose pointed at the proper horizontal angle, and the plane would then begin an uncontrollable dive.

Reportedly, the crash of Alaska's MD-80, which killed more than 80 people, was caused by its balance system.

Statistics from Boeing China Inc indicate that there are no MD-80 airplanes operating in China.

An examination report received yesterday by China Daily from China Eastern Airlines announced that the examination work was completed Monday night, with all airplanes in good condition.

The company's five MD-82 and nine MD-90 airplanes are operated by its subordinate companies located in Anhui and Shandong.

To ensure safety, the company said it would soon conduct non-scheduled examinations to those planes.

China Northern Airlines owns 25 MD-82 and 11 MD-90 planes which all fly domestic routes.

Sources with the airline said that it had managed to examine its group of MD planes, but did not elaborate on the specifics of the examinations.

A CAAC official, who asked not to be named, said: "We have confidence to guarantee the good mechanical conditions of our airplanes, no matter what kind, big or small."