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Accession Number:
ADP002198
Title:
Electromagnetic Measurements of Lightning Attachment to Aircraft,
Descriptive Note:
Corporate Author:
AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH
Report Date:
1983-01-01
Pagination or Media Count:
8.0
Abstract:
A NOAA WC-130 aircraft instrumented with electromagnetic field sensors was flown in South Florida in close proximity to thunderstorms in the summer of 1981. Electromagnetic field measurements of two direct lightning attachments to the aircraft were recorded in a continuous analog recorder with a frequency response of 2 MHz on 17 July and 26 Aug. The 17 July flash lasted 295 msec and was characterized by about 200 individual pulses with a maximum pulse repetition rate of 10,000 pulsessec. The maximum uniform current of any of the isolated pulses was 650 Amperes. The risetimes of these pulses ranged from less than 350 nsec to about 12 microsec. This flash had a continuing current of 50 A, caused eleven small burn marks along the fuselage and burned through one of two external antenna wires on top of the aircraft. The 26 Aug flash lasted 460 msec and was characterized by about 300 individual pulses with a maximum pulse repetition rate of 10,000 pulsessec. The maximum uniform current of these pulses was 3 kA. The risetime of these pulses ranged from less than 350 nsec to about 10 microsec. There was no evidence of a continuing current component in this flash. These aircraft lightning strikes and many others presented in the literature indicate that the physical mechanisms of most lightning attachments to aircraft are different than those of cloud-to-ground and intracloud lightning. This paper presents an analysis of the WC-130 direct strikes and a description of a possible mechanism for lightning attachment to aircraft.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
