Page:CAB Accident Report, Eastern Air Lines Flight 14.pdf/15

 this accident occurred, it is regettable that the instrument which was being carried was not in operation, for a barograph record would have been of inestimable value in determining the degree of turbulence encountered by NC 21727.

In seeking to determine the cause of the accident to Eastern's Trip 14, we have concluded previously in this report that the aircraft had been properly maintained and was in airworthy condition when it took off from West Palm Beach. We have also determined that there was no structural or mechanical failure of the aircraft or any of its equipment until it crashed with power on into the swamp west-southwest of Vero Beach. It also appears that the airplane was properly loaded and that it had ample fuel for the flight. From the evidence it is clear that the radio range stations involved, Miami and Melbourne, operated and maintained by the Civil Aeronautics Administration, were operating normally on April 3, 1941.

The investigation included a study of the forecasts made by the United States Weather Bureau and Eastern's Miami meteorologists, the hourly weather sequence reports, and the weather conditions that actually existed along the Florida sector of Route 6 on the morning of April 3, 1941, to determine whether Trip 14 should have been dispatched and whether the trip was furnished current weather information while en route to Jacksonville.

The weather forecasts made by the United States Weather Bureau covering the period from 5:30 A.M. to 1:30 P.M. and the trip forecast made by Eastern's Miami meteorologist at 5:20 A.M. both predicted that there would be scattered thunderstorms along the Florida sector of the route. The prediction did not indicate that the weather conditions to be encountered would be in any respect unusual for the Florida area at that time of year. This prediction was borne out by the weather observations contained in the 6:35 A.M. weather sequence reports. However, the 7:35 A.M. and 8:35 A.M. weather sequence reports indicated the approach of more unfavorable weather conditions. The 7:35 A.M. weather sequence report indicated general thunderstorm and shower activity extending eastward across the State of Florida, with Tampa reporting a northeast wind of 32 m.p.h. with strong gusts and light rain showers. Both Orlando and Daytona Beach reported mild thunderstorms. The rain area extended about 120 miles northward from Tampa and Daytona Beach. The 8:35 A.M. weather sequence report showed an extensive thunderstorm and rain area in the central part of Florida. Tampa reported a northeast wind of 28 m.p.h. with strong gusts and a thunderstorm with rain showers. West Palm Beach and Vero Beach were reporting thunderstorms. The rain area extended north to Tallahassee on the west coast of Florida and to Jacksonville on the east coast.

In determining the characteristics of the thunderstorm activity as it actually occurred, we have, in addition to the Weather Bureau sequence reports, the observations of the Fort PierePierce [sic] Coast Guardsmen, the testimony of the pilots flying four of Eastern's trips in that area and the statements of the crew and passengers of Trip 14. From this evidence we conclude that the storms in the vicinity of Vero Beach were accompanied by heavy turbulence, lightning, heavy rain, and hail. The reports of uprooted trees indicate that wind velocity in gusts may have ranged up to 40 or even 60 m.p.h. in certain portions of the storm although no official reports of such high velocity were recorded at any Weather Bureau station in the storm area. This general thunderstorm activity which extended in a line across the State of Florida by 7:35 A.M. with winds northerly or northeasterly in the northern portion of the thunderstorm area was probably of a cold front type with thunderstorms caused by the 5—30827