An Airborne Express cargo jet crashed Dec. 22 in Narrows, Va., because the crew performed a maneuver improperly during flight tests, and airline management failed to provide the proper guidance and training for the maneuver, the National Transportation Safety Board said yesterday.

The four-engine McDonnell Douglas DC-8 slammed into a mountain, killing the three crew members and three maintenance technicians aboard.

The plane, which took off from Greensboro, N.C., was being put through "functional evaluation" tests before being placed in regular air cargo service. The maneuver that caused the crash involved deliberately stalling the aircraft briefly to test whether the "stick-shaker" stall warning was set properly.

In a stall, the flow of air over the wing is disrupted, robbing it of lift.

The board said Airborne Express failed to set proper guidelines, requirements and pilot training for functional evaluation tests. The report said Airborne Express, unlike other major cargo carriers, allows nighttime tests, and it said the company should not have allowed the pairing of pilots who had never performed a stall maneuver.

In a statement yesterday, the company challenged many of the NTSB's conclusions.

The statement said the crew was properly trained and familiar with the company's functional evaluation program. The company said it maintains a strong reputation for a well-run operation and is committed to continuing to do so and ensuring employee safety.