Evaluation of the US Army Fitting Program for the Integrated Helmet Unit of the Integrated Helmet and Display Sighting System

摘要

In June 1985, the US Army began fielding a new aircraft known as the Advanced Attack Helicopter, the AH-64. Integral to this new aircraft is a monocular helmet-mounted display system, the Integrated Helmet and Display Sighting System (IHADSS). Along with various electronic components, the IHADSS includes a helmet referred to as the Integrated Helmet Unit (IHU). The purpose of the IHU is to provide the aviator with basic impact and noise protection. In addition, it serves as a platform for the display system, composed of a miniature, 1-inch diameter, cathode ray tube (CRT) and an optical relay device, the Helmet Display Unit (HDU). The basic fitting process involves numerous steps including, but not limited to, adjustments to the suspension system, proper location and alignment to the HDU, and final trimming of the helmet visor to accommodate the HDU when in the operating position. The objectives of the fitting procedure are to: a) obtain a comfortable, stable fit of the IHU, which will enable the aviator to achieve the maximum field-of-view provided by the HDU when it is mounted on the helmet and b) achieve boresight, which permits accurate engagement of weapons systems. This report documents the fitting program established at USAARL, its successes and deficiencies, and presents recommendations for designing a fitting program which, will ensure that the man-machine interface, as provided by the helmet, is optimized.