Page:CAB Accident Report, West Coast Airlines Flight 703.pdf/6

 the Board believes that both powerplants were capable of normal operation at time of impact.

The possibility of pilot incapacitation was explored. However, post mortem examinations revealed no evidence of any incapacitation. Further, these examinations showed that all three occupants were wearing seat belts at time of impact and died, not of injuries received in the accident but of exposure and drowning.

The weather was good and could not have been contributory to the accident the exception that the light southerly wind would have been conducive to a near calm water surface. Such a surface could have been dangerously deceptive to gauge altitude. The direction of flight was toward a low afternoon sun and subsequent glare could also have made altitude reference from the water more difficult.

As the left altimeter had been set to road within 10 feet of correct altitude (30.40" rather than 30.05"), it was correct for all practical purposes. There is no way to account, except by inadvertence, for the right altimeter being set too high by about 180 feet.

In the light of the foregoing and in conjunction with the lack of any radio message indicative of trouble, there appears to be no explanation of why the aircraft was flown into the water other than simultaneous preoccupation or lack of vigilance, of all three crew members. The following is offered as the most logical explanation

1. The trainee on the left would not have been primarily concerned with altitude. Instead, he should have been principally concerned with increasing his airspeed and rate of descent. According to the tape heading trace, he was devoting considerable attention to maintaining a heading. ln accordance with company training manual he normally would have been expected to continue descent until advised otherwise by the check pilot. The instrument flight shield before him would surely have been removed had there been any actual operational trouble.

2. The check pilot on the right must have believed it best to let the trainee continue descent, hoping that the trainee would momentarily establish the required higher airspeed and greater rate of descent. To continue with this hypothesis process may have been carried so far that it was not possible to recover, considering the probable deceptiveness of the water surface. This theory presumes, of course, that the captain was either not watching his altimeter or knowingly went so low-that he struck the water while his altimeter, inadvertently set to read 180 feet high, still showed a positive altitude above the lake surface.

3. The FAA Inspector, in the observer's seat, must also have been unaware of the dangerously low altitude possibly for the same reasons as the check pilot. There remains also the possibility that he was engrossed in paperwork, perhaps in connection with the subject flight.

As a result of this accident the Civil Aeronautics Board, on July 17, 1963 recommended to the Administrator of the Federal Aviation Agency that FAA Training Manuals of air carriers prescribe terminating altitudes for simulated emergency descents to provide safeguard against the hazardous prolongation of such descents.