Every month, six small airplanes built for the U.S. Navy roll off a production line in Kansas and are immediately placed in storage. The reason? The $488,000 planes aren't safe to fly.

The Navy now has 54 Beech T-34C trainer planes in storage, said a Navy Spokesman. Another 18 will be built by October, the spokesman said, and 21 more are scheduled for delivery before the end of the calender year.

Each of the planes, the spokesman said, has a problem that caused a non-fatal crash of one Beech T-34C in January - a flutter in a wing control surface called an aileron that causes pilot to lose control of the plane while in flight.

The airleron is a movable flap on the back of the wing that is used for banking and turning. The problem with the aircraft occurs, the navy spokesman said, when the plane is flown near its maximum speed of just under 400-miles per hour, and air flow over the aileron causes it to flutter.

The Navy is not sure how much it will cost to fix the T-34Cs it is receiving. The Kanasas - based Beech Aircraft Corp., manufacturer of the plane, is working on a redesign of the aileron, the spokesman said, but has not yet produced a satisfactory replacement.

"Since the final form of the modification has not yet been determined," said the spokesman, "the cost of refitting the T-34C is not known at this time."

He added the Navy feels it would be more costly in the long run to stop production of the T-34 than to continue to produce the defective plane and repair the problem when the new aileron is designed.

The Beech operation in Bedrose, Kan. has been routinely shut down for two weeks said a company lobbyist here, and no one in a position to comment on the plane's production problem was available.

When the T-34C is fixed and put into service, it will be used for student pilots taking basic flight training at Whiting Field near Pensacola, Fla. The pilots who will use the plane are ROTC graduates and officers newly commissioned from the aviation Offi plans calls for the Navy to begin training flight instructors on the T-34C in October, and for the plane to go into full use in January, 1973. The spokesman said the use of the plane has already been pushed back several months because of the aileron problem.

The T-34C that crashed during a test flight Jan. 27 was piloted by a Beech employee who was attempting to push the plane to its maximum speed. The spokesman said aileron flutter was deliberately induced during the test flight to determine the extent of the problem.

The Beech pilot was not critically injured in the crash, the spokesman said.