As known to the world, the U.S. invested huge fund in producing new type F-22 Raptors of the new generation.

F-22 Raptor, a multi-purpose fighter, was jointly developed by military monopolies Lockheed Martin, General Dynamics and Boeing Co. to replace F-15 fighters.

A group of pilots of the U.S. Air Force recently refused to make flights aboard F-22 Raptors.

The reason was that hypoxia in a cockpit is common occurrences during flight.

A pilot died of hypoxia when making flight above Alaska in November 2010 and the plane ended up in a crash.

The hypoxia in F-22 Raptors happened more than ten times, but the cause has not yet been found out.

The manufacturers of the plane deliberately lowered the flight altitude of the fighters as a stop-gap measure but the lack of oxygen is so serious as to make pilot faint.

Pilots have thus become reluctant to make flight aboard such fighters which threaten their lives.

A spokesman for the U.S. Air Force officially admitted that pilots are feeling uneasy about it.

A number of doctors and psychologists as well as engineers and analysts went busy setting up a special filter for measuring the concentration of poisonous materials in a cockpit. This resulted in a story that poisonous materials could be formed during flight.

More than 190 Raptors have so far been produced costing huge fund for their manufacture. The production of the fighters has thus been suspended with their weak point being brought to light.

It serves the U.S. right as it defied the demand of the working majority for the rights to work and live and spent huge money to arms buildup to attain its ambition to dominate the world.