Page:CAB Accident Report, Pennsylvania-Central Airlines Flight 17.pdf/13

- 12 - at the northwest and southwest ends of the field. It was brought out at the hearing that when such observations indicate one mile visibility on the airport itself, it is possible, because of the industrial area in which the airport is located, to have less than one mile visibility in the immediate vicinity of the airport due to localized smoke conditions. Such conditions are, of course, a serious handicap to the pilot in avoiding the numerous obstructions in the vicinity of the airport and in attempting to line up for a landing.

As a result of the investigation of this accident the Board has called the attention of the Weather Bureau to the problem of measuring visibility in the vicinity of airports subject to localized smoke conditions, and the Weather Bureau has adopted a new means of making such measurements. Under the new procedure visibility markers are established at more frequent intervals around the airport. In addition if one of the markers at a given distance, 1 mile for example, cannot be distinguished, the visibility is reported as the given distance with a notation that the visibility is less than that in the direction of the indistinguishable marker. Such information is, of course, of considerable help to a pilot in selecting a safe approach path and in making the actual approach.

CONCLUSION

Findings

Upon all of the evidence available to the Board at this time, we find that the facts relating to the accident involving aircraft NC