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Captain DeWitt had acquired a total of 48:13 hours in Electra aircraft at the time of the accident. After completion of Electra transition training, he also flew approximately 14 hours in DC-6 and DC-7 aircraft before being assigned to electra line operations on January 25, 1959.
The American Airlines Flight Manual requires the ceiling and visibility landing minimums prescribed in the Operations Specification - Airports, to be increased by 100-feet ceiling and one-half mile visibility whenever the captain in scheduled operation has not served for 100 hours as pilot-in-command on the equipment, or until such time as the captain is certified by his Regional Superintendent of Flying, as qualified to operate at the landing minimums prescribed. The company had check pilots ride with all captains on Electra equipment until they were qualified for lower minimums. The American Airlines Regional Superintendent of Flying authorized the removal of these restrictions on Captain DeWitt January 25, 1959, when he had 12:32 hours of flying the Electra in scheduled operations.
The correct procedure for making a backcourse ILS approach to runway 22 at La Guardia is outlined in the American Airlines Flight Manual carried by the pilots of N 6101A; cross the La Guardia Range at the minimum height of 800 feet (820 above sea level) at 140 knots; when over the center of the La Guardia Range station, commence an immediate descent while maintaining 140 knots; level off at 400 feet, the minimum Electra ceiling for one mile visibility, and increase power to maintain level flight until the landing runway is sighted or the time to execute the missed approach procedure arrives. This is approximately one minute and 15 seconds past La Guardia Range. The ILS approach plate for runway 22 is appended to this report.
Should the pilots establish visual contact with the runway at the 400-foot minimum altitude, they may have to make final directional changes for proper runway alignment, lower flaps to landing position, lower and turn on landing lights, and descend the 400 feet to the runway.
ANALYSIS
Testimony received by the Board indicates that Captain DeWitt had engaged the autopilot after the takeoff climb from Chicago. Since it did not operate correctly in the "manual mode" position, a malfunction which was written in the aircraft logbook, the autopilot was engaged in the "heading mode" position for the remainder of the flight, including the instrument approach.
The only other unusual events of record during the flight and prior to reaching New Rochelle were a drift off course from Amber 7 Airway before reaching the Sparkhill intersection; the discrepancy of 30 degrees in the first officer's RMDI; a right turn short of the localizer centerline just prior to reaching New Rochelle; and a reported slow response by the crew to instructions from La Guardia Approach Control.
Since the flight to New York was uneventful except for the above mentioned incidents, this Analysis will concentrate upon the final segment of the flight path. (See Approximate Flight Path, Appendix B.)
The weather at La Guardia Field, the weather known to prevail in the New Rochelle La Guardia area, and the weather reported by the flight immediately preceding Flight 320, make it highly possible that Flight 320 could not have been observed from the ground immediately prior to the range station at an altitude much above 400 feet. That this final descent had been initialized at an altitude less than
