Rotorcraft TCAS (Traffic Alert and Collision Avoidance System) Evaluation Group 2 Results.
Abstract
This report contains results of Group 2 testing of a Traffic Alert and Collision Avoidance System (TCAS) installation in a Sikorsky S-76. Of the three groups in the S-76 TCAS evaluation effort, Group 2 was the most substantive because the important work of specifying the characteristics of the antenna installation and the particular effects of multipath were both accomplished. Transmitter and receiver specifications were also developed. Two antenna sites, one atop the nose and one on the underside of the tail boom, were evaluated. Each site is a suitable location for a single antenna TCAS. The bottom antenna has better bearing performance and slightly better coverage, while the top antenna is far less corrupted by multipath. Relative merits of each antenna will be further evaluated. Through examination of flight data, a three-step multipath elimination algorithm was developed. It will be implemented and evaluated as part of Group 3 flight data reduction. Minimum transmit power and receiver sensitivities were specified, based on a 90% probability of reply and a target range of 4 miles forward and 2.8 miles rearward. Effects of general aviation transponder characteristics and TCAS antenna patterns were also considered. Keywords: Aircraft antennas, Rotary wing aircraft.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1986
- Accession Number
- ADA176040
Entities
People
- Albert J. Rehmann
Organizations
- Federal Aviation Administration