Traffic Alert and Collision Avoidance System (TCAS) Surveillance Performance in Helicopters

摘要

Subsequent to the development of TCAS(Traffic Alert and Collision Avoidance System) equipment for fixed-wing aircraft, a follow-on effort addressed the suitability of such equipment for use in helicopters. This program focused on those differences between helicopters and fixed-wing aircraft that might be expected to affect TCAS performance: the large rotor, the relatively irregular shape of the fuselage, the low speeds and high turn rates typical of helicopter flights, and the over-water and low-altitude conditions typical of helicopter operations. A Bell Long Ranger helicopter was acquired and equipped with experimental TCAS equipment with full data recording capability. Flight experiments were conducted to assess air-to-air surveillance performance under challenging conditions. Other flights involved guest pilots for subjective evaluations of the TCAS performance. It was concluded that the air-to-air surveillance techniques that were originally developed for use in large jet airliners will also perform satisfactorily in helicopters. The bearing accuracy of traffic advisories, while somewhat degraded because of the effects of the rotor and the shape of the helicopter fuselage, will nevertheless be sufficient to aid the pilot in visual acquisition of traffic. It was also concluded that, because of the flight characteristics of helicopters, the pilot display should consist of traffic advisories alone, without resolution advisories. Keywords: Collision avoidance; Angle-of-arrival.