Accession Number : AD0654886

Title :   EXPERIMENTAL TRIGGERING OF NATURAL LIGHTNING (IN RELATION TO EFFECTS ON NEAR-BY AIRCRAFT).

Descriptive Note : Technical rept.,

Corporate Author : LIGHTNING AND TRANSIENTS RESEARCH INST MINNEAPOLIS MINN

Personal Author(s) : Stahmann,J. R.

Report Date : MAR 1966

Pagination or Media Count : 65

Abstract : Natural lightning was triggered by directing rockets, trailing thin stainless steel wire, from the Research Vessel Thunderbolt toward charged clouds. One objective was to attempt to trigger the strokes through an F-100 jet flying over the ship. The F-100 carried many recording instruments to measure the effects and characteristics of both direct and nearby lightning strokes. Measurement equipment was also provided on the ship to obtain coordinated stroke characteristics at the sea level stroke termination point. These data are important for lightning protection of aircraft studies, particularly around fuel vent areas. Data concerning current waveform, blast pressure waves and plasma extent were obtained. It was shown that strokes can be triggered about 50% of the time in medium to high electric fields. The lightning hazards to the F-100 were considered and protective measures were devised for the fuel vent and canopy areas. These measures and the aircraft instrumentation were checked with simulated lightning by bringing the aircraft and Thunderbolt together at the Mayport Naval Air Station, Florida. The discharge currents triggered were below the very intense strokes desired and fair weather during the operational period limited results. Since questions concerning blast pressures, plasma extent and other properties of severe lightning remain unresolved, it is important to continue the program in a region where storms with severe strokes may be intercepted with high frequency. Such a location may be found near or north of Tampa on the west coast of Florida. (Author)

Descriptors :   (*LIGHTNING, *AVIATION SAFETY), AIRCRAFT, HAZARDS, LIGHTNING ARRESTERS, EXPERIMENTAL DATA

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE