A new attack helicopter, intended to usher the Army into high-technology aviation, has broken down so often that one commander said he would rather fly a 1960s-vintage chopper "if we went to war tomorrow," it was reported Sunday.

All 12 of the new high-technology AH-64 Apache helicopters became incapacitated at least once within five days during a recent Army gunnery exercise, an internal Army memo obtained by The Los Angeles Times said.Twenty of the new choppers are scheduled for delivery to the Utah Army National Guard's 211th Aviation Group in West Jordan beginning in December. Pilots and support personnel from the group have already begun training in the new aircraft.

Maj. Gen. John L. Matthews, Utah's adjutant general, said he read news reports about problems with the Apache but believes they are related to the development of the new aircraft. "It's not uncommon for a complex machine like that to have problems."

The Apaches' anticipated arrival in Utah marks a significant change for the Guard in the military pecking order because the Guard is used to training with older equipment, Matthews said. "The Guard over the years has never had to worry about getting the bugs out of new equipment because we've never had any."

The failures are believed part of a larger problem with the aircraft, prompting Rep. John Dingell, D-Mich., to call for a General Accounting Office investigation.

Army officials disputed allegations that the AH-64 - on which they eventually plan to spend $13.6 billion - is a lemon and said it is meeting reliability goals.

The helicopters, costing $13.4 million each, are produced by the McDonnell Douglas Helicopter Co. in Mesa, Ariz. A total of 975 have been ordered by the Army.

Dingell's staff, however, recently uncovered a memorandum and cover letter concerning Army concerns about the helicopter, written by Col. R. Dennis Kerr, commander of the 82nd Aviation Brigade at Fort Bragg, N.C., The Times said.

"I have been a fan of the AH-64 for over a year, but the aircraft has let me down," Kerr wrote on Feb. 7 to Maj. Gen. Richard Stephenson, commander of the Army Aviation Systems Command in St. Louis.

"If we went to war tomorrow, I'd have to recommend taking all of our AH-1s before we outload one AH-64. We need helicopters to work for at least the first 72 hours. The Apache has a long way to go to make it to the battlefield. Please help."

The AH-1 is Bell Helicopters' 1960s-era Cobra, which is still used by the Army, including the Utah Army National Guard.