Page:CAB Accident Report, Pan American Flight 203.pdf/11

- 10 - operated the trip prior to arriving in the vicinity of San Juan. He began his final approach without receiving landing instructions which appears to be contrary to Pan American's established procedure. While, as previously indicated, this failure clearly appears to have had no bearing upon the subsequent accident, it constitutes an act of carelessness which cannot be condoned. The failure of the pilot's radiotelephone provides no excuse for this lapse since by delaying the landing for a few minutes, instructions could have been secured by the ship's radio operator.

Captain Lorber landed downwind and in a direction opposite to that indicated by the landing lights laid out by Pan American's ground crew. There appears to be no justification for this violation of standard procedure. While landing a flying boat in the most convenient direction irrespective of the direction of very light winds has generally been considered as a safe practice, Captain Lorber's action in this instance is subject to criticism because of the careful preparations which had been made by the ground crew for his landing. The landing launch is carefully located with respect to the landing area lights in order that it can assist in marking the landing area by the beam of its search—light and in order that it can be as close as possible to the point at which the airplane first makes contact with the water. By landing in the wrong direction Captain Lorber made it impossible for the landing launch to perform these vitally important functions with maximum speed and efficiency. At the time of the accident the wind was variable, although generally from a westerly direction, and of approximately 3 m.p.h. velocity.

Various passengers and both stewards, who were seated in different cabin compartments, testified that they were thrown violently against their safety belts. This appeared to them to have occurred almost simultaneously with the landing. The conclusion to be drawn is that this severe deceleration started at the time of, or very shortly after, initial contact with the water. Such a deceleration occurring nearly simultaneously with first contact would have resulted from an extremely nose-low landing. A preponderance of testimony indicates that passengers were thrown violently sideways about the same time that they were thrown forward. This is an extremely strong indication that the right swerve experienced by the aircraft also had its origin simultaneously with or immediately following first contact with the water. This, in turn, could be caused by, and leads to the conclusion that, the aircraft was making some leeway, i.e., side motion relative to the water, when it first contacted the water. Although lay testimony is not often of primary importance particularly in cases involving so precise a maneuver as the night landing of a large flying boat, it appears that a quite accurate reconstruction of the accident can be accomplished from the testimony referred to above. These cabin occupants were unable to see either directly ahead or directly downward and were therefore unable to testify accurately regarding the attitude of the aircraft prior to the time of first contact. However, their testimony as to events subsequent to the time of first contact, taking due cognizance of the short interval elapsed, clearly establishes the nature of the landing. The conclusion that must inevitably be drawn is that contact, severe longitudinal deceleration, and violent turning occurred almost simultaneously. Such a set of conditions would result if first contact with the water was made while the aircraft was nose-down and moving laterally relative to the surface of the water.

This conclusion is supported by an analysis of the forces present during the landing of a marine aircraft. We find that when the ship first contacts the water the point of initial contact is in the neighborhood of, or slightly ahead of, the step. The step itself is located a short distance astern of the center of gravity. In other words, the point of first contact, from which the initial retarding force acts, is in the neighborhood of the vertical projection of the center of gravity. This means that there is little, or at most, a 20494—5