Page:CAB Accident Report, Eastern Air Lines Flight 663.pdf/15

Rh The lack of horizon and the black background conditions presented to the DC-6 flight crew were almost identical to those confronting the flight crew of Flight 663. Flight Test Program A flight test program was undertaken-to reproduce as closely as possible the situation in which the crew of EAL 663 found themselves on the night of February 8, 1965. The Civil Aeronautics Board's Bureau of Safety staff assisted the PAA in the establishment of the program. A total of four flightpaths were developed, three simulating possible tracks of EAL 663 and PAA 212, and the fourth simulating the conditions of the DC-6 and the B-707 near miss on June 2, 1965. In addition to the normal crew on the test DC-7 aircraft, three subject pilots were utilized on each of the three nights on which the flight tests were run. It was not the intent to reproduce the original flightpaths of the airplanes, but rather to find out the reactions of the subject pilots while in environmental conditions similar to those experienced by the crews in the aforementioned accident and incident. Following are the intital reactions reported by the pilots involved in the tests. On the first night the subject pilots were briefed as to the expected altitudes of the two airplanes. This depth of briefing was discontinued on the two succeeding nights. Of the six subject pilots who were unaware of the minimum vertical separation, five reported the illusion that the target (B-707) seemed to be climbing as it neared the DC-7 while, in fact, it was descending throughout the test. Two of the five experienced this illusion twice. Of particular significance was the report of one captain of the DC-7 that he had the illusion that his airplane was pitching over on the target aircraft. He checked his instruments to assure himself that he was still climbing but when he looked back at the B-707 he again experienced the illusion. This illusion occurred even though this captain had been fully briefed. He had flown the test runs during the day and had flown all of the tests the previous night. At the time of this experience he was flying from the first officer's seat.

1.16 Other Aspects

At the time of the last communication from EAL 663, 1825:36 there was apparently no distress in the cockpit. It is assumed that the flight crewmembers at this time were capable of performing their duties with respect to the flight. The PAA 2l2 crew indicated that, at the time of passing, the DC-7 was in a right bank of approximately 96 degrees at an altitude of approximately 2,600 feet. The calculated time of passage is 1826:26. The airplane lost 2,600 feet and recovered to an almost normal attitude in the next 14 seconds when it hit the water at 1826:40. The 14 seconds from passage to impact is compatible with the results of an IBM digital computer program provided by the Douglas Aircraft Company in those cases where impact or near impact resulted. A number of cases were evaluated by the computer with the "hands off" condition during that portion of EAL 663 from passage to impact. The aircraft was held