Page:CAB Accident Report, Boeing Test Flight Crash on 19 October 1959.pdf/1

A 347 File No. 2-1754

CIVIL AERONAUTICS BOARD

AIRCRAFT ACCIDENT REPORT

ADOPTED. June 13, 1960 RELEASED June 20, 1960

BOEING AIRPLANE COMPANY; BOEING 707—227, N 7071, NEAR ARLINGTON, WASHINGTON, OCTOBER 19,1959

On October 19, 1959, at 1620 P s t., a Boeing 707-227, N 7071, crashed and burned in the Stillaguamish River about 10 miles northeast of Arlington, Washington. Four of the eight occupants aboard received fatal injuries; one of the four survivors received serious injuries.

A Boeing Airplane Company test pilot was acting as an instructor-pilot on a demonstration and acceptance flight prior to the aircraft being delivered to the customer. The company was also utilizing this flight time for flight instruction purposes in qualifying airline personnel in the aircraft.

The instructor-pilot demonstrated several maneuvers, including Dutch Rolls, to a pilot-trainee, an airline captain who was making his first training flight prior to checkout on the Boeing 707

The instructor-pilot initiated a Dutch Roll in which the roll-bank angle of the aircraft reached 40 to 60 degrees. This bank angle is in excess of limitations set by the company for demonstration of this maneuver. The pilot-trainee, who was to make the recovery, rolled full right aileron control while the right bank was still increasing. The aircraft immediately yawed and rolled violently to the right. The instructor-pilot immediately rolled in full opposite aileron. The airplane stopped its right roll at a point well past a vertical bank and then rolled to the left even more violently. Several gyrations followed and after control of the aircraft was regained, it was determined that three of the four engines had separated from the aircraft and it was on fire. The fire rapidly reduced controllability of the aircraft and an emergency landing was attempted, however, the aircraft struck trees and crashed short of the intended landing area because power on the engine remaining had to be shut down to keep the aircraft wings level

Subsequent to this accident the Boeing Airplane Company flight training syllabus was revised to reemphasize the maximum roll-bank angles permissible for the Dutch Roll maneuver. In addition, demonstration of the Dutch Roll has been put off until a later time in the curriculum so the pilot-trainees will have more flight experience before practicing the maneuver.

N 7071 was a new model of the Boeing 707 series aircraft on which FAA type certification flight tests had just been completed. Final certification was awaiting verification of these test results and the aircraft meanwhile was being USCOMM-DC-25378