Page:CAB Accident Report, TWA Flight 6.pdf/31

   The purpose of this device is to give a continuous observation of the height of clouds and through proper setting of the instrument a change in the ceiling to some predetermined lower value would automatically set off an alarm. When such device is in operation, scud clouds moving across the field would be detected in this manner.

The Board has recommended to the Administrator that when a solid cloud cover prevails at an altitude of 800 feet or less and the horizontal visibility is officially reported to be less than five miles, the height of the ceiling shall be from the base of the lowest cloud form officially reported. The Board suggested that this recommendation be made effective and enforced until such time as additional studies indicated that other action of a more fundamental and permanent character should be taken. It is understood that such action was taken by the Administrator immediately to carry the recommendation into effect. 