Page:CAB Accident Report, TWA Flight 3 (June 1942).pdf/7

 When Flight 3 was informed of the zero visibility conditions at Dayton, caused by dense ground fog, Captain Hortman reported to the company radio operator that west of the field he had three miles forward visibility. The operator advised the CAA operator and weather observer of the pilot's report and asked if a special report would be filed, showing this information. The CAA operator replied that zero conditions still prevailed on the ground; therefore, no special report could be given. The pilot of TWA Flight 3 then exercised his emergency authority and landed the aircraft at Dayton at 3:44 a.m.

The terminal forecast for Dayton, Ohio, issued by the U. S. Weather Bureau predicted the formation of fog at Dayton, with decreasing visibility becoming about one mile by 1:30 a.m. on June 27, 1942, and to near zero by 4:00 a.m. The forecast issued by TWA predicted ground fog forming at Dayton with visibility three miles at midnight, decreasing to ½ mile by 4:30 a.m. The actual weather report shows that Dayton was closed at the time of the accident, with zero visibility caused by dense ground fog. The difference between the forecasts and the actual conditions which prevailed at the time of the accident is relatively small. The actual conditions were, therefore, within a reasonable tolerance to what would have been expected by the forecasts.

The flight was re-dispatched to Toledo at 3:06 a.m. The captain said he had based his decision to land at Dayton on the forecasts he had used at New York, showing a very small spread between temperature and dew point at Detroit, Fort Wayne, Toledo and other points along the northern route. He testified that Dayton had closed in slightly earlier than was forecasted by the TWA