Page:CAB Accident Report, Northeast Airlines Flight 715.pdf/9

 -9- were taken in this matter at New York, New York, on June 19, 1964.

Northeast Airlines, Inc., is a Massachusetts corporation With its principal office in Boston, Massachusetts. The corporation holds a certificate of public convenience and neceSSity issued by the Civ1l Aeronautics Board and an air carrier operating certificate issued by the FAA. TheSe certificates allow the carrier to engage in air transportation of persons, property, and mail over the route involved.

2.1 AnalXSIS

The flight was routine from Boston to LaGuardia where a higher than normal traffic pattern for runway 31 was established.

It was stated by the captain that the VASI approach path was intercepted on final approach at an altitude of approximately 600 feet about 1-1/2 miles from the threshold. He further stated that the remainder of the approach was made utilizing the VASI and that “on-glidepath" color indications were ob- served up to the time of impact With the dike.

Inasmuch as the VASI system was operating satisfactorily at the time of the accident, as determined by the investigation, the captain's testimony of receiv- ing the proper on-glidepath color indication is not compatible, and cannot be reconCiled Wlth the aircraft's striking the dike. Even if the aircraft was flown at the lower limits of the glidepath, that is to say With the pilot‘s eye level at the bottom of the wedge-shaped band of the proper on-glidepath light array, there still would have been approx1mately 24 feet remaining between the top of the dike and the bottom of the main landing gear.

Therefore, the Board believes that the captain did not properly utilize the VASI system during the final phase of the approach.

Careful examination of the aircraft's hydraulic system failed to reveal any Significant defect, such as appreCiable leakage, which might have a110wad an unwanted partial flap retraction. The only positive eVidence of the degree of flap extenSion at impact was the left inboard flap actuator rod which had a slight gradual bend With its center seven inches from the rod eye fitting jam locking nut. This damage occurred when the aircraft contacted the runway exerting an upward force on the flaps thereby creating a compressive load in the actuator rod greater than its column strength. Seven inches of inboard actuator rod extension corresponds to 20 degrees of flap extension, therefore, the flaps would necessarily have been extended more than 20 degrees when this damage occurred.

Based on the crew's testimony wherein the captain stated that he called for full flaps shortly before the aircraft contacted the dike, as well as the flight engineer's confirmation of the 50-degree flap selection being accomplished it is strongly indicated that the flaps were in the full down or near full down