Page:CAB Accident Report, Pennsylvania-Central Airlines Flight 143.pdf/23

 Consideration was also given to the possibility of the presence in the air induction system of a single rag or other foreign material large enough to cause the engine to lose power. It is improbable that such a rag or other foreign material would have passed through the propeller to the screen at the outer entrance to the cold air duct. If such a large rag or other foreign material did pass intact through the propeller to the screen, and such an occurrence has never come to the attention of the Board, it would be held tightly against the screen by force of the airflow. If this were to happen, it would probably occur during the take-off run, and the engine would stop instantly before the airplane left the ground. As we have seen, the right engine of NC 13359 was not adversely affected until after the airplane had been in the air about five seconds and even then the engine ceased to deliver power not abruptly, but as if throttled back. To test the effect of the presence of a large rag in this position a representative of the Safety Bureau placed a piece of fine-weave doubled burlap entirely across the cold air duct of a similar engine. Enough air filtered through this cloth to permit the engine to operate normally.

It is conceivable that someone might have left a large rag or other foreign material in the induction system behind the screens. If this had happened, however, the rag or other material would have been caught by the carburetor grid and would not have passed through the engine. There was no large rag or other material found against the carburetor grid of the right engine of NC 13359. Nevertheless,