This SAE Information Report is a summary of information obtained by way of survey conducted during the 2Q and 3Q of 1997 of MAYDAY system manufacturers. The data represented here has been condensed from the original survey that was conducted by telephone interviews and faxes. The information contained within is limited to technical data as it pertains to vehicle and on-board MAYDAY system operations. It does not contain business, marketing, or any proprietary technical information. The complete survey results are in the possession of the SAE.