Federal Aviation Administration June 8, 2011 – Federal Register Recent Federal Regulation Documents

The FAA is amending its lightning commit criteria to account for new information about the risks of natural and triggered lightning. This action amends flight criteria for mitigating against naturally occurring lightning and lightning triggered by the flight of an expendable launch vehicle through or near an electrified environment in or near a cloud. These changes will increase launch availability and implement changes already adopted by the United States Air Force.

The Federal Aviation Administration (FAA) amends the lightning protection airworthiness standards by establishing new lightning protection regulations for electrical and electronic systems installed on aircraft certificated under parts 23, 27, and 29, and revises lightning protection regulations for electrical and electronic systems installed on airplanes certificated under part 25. This rule establishes two levels of lightning protection for aircraft systems based on consequences of system function failure: Catastrophic consequences which would prevent continued safe flight and landing; and hazardous or major consequences which would reduce the capability of the aircraft or the ability of the flightcrew to respond to an adverse operating condition. This rule also establishes lightning protection for aircraft systems according to the aircraft's potential for lightning exposure. The airworthiness standards establish consistent lightning protection requirements for aircraft electrical and electronic systems.

We propose to adopt a new airworthiness directive (AD) for the products listed above that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: