Analytical Investigation of an Improved Helicopter Landing Gear Concept.

摘要

A design study has been conducted to define a landing gear concept that redistributes the impact energy of an autorotational landing in a manner that minimizes the occurrence of blade/tailboom strikes. The landing gear concept redistributes the impact energy by providing an interconnection between the front and rear landing gears. Through the interconnection, as the rear landing gear moves from the flight static position toward the full in position under landing impact, the front gear is impelled to move from the flight static position toward the full out position. When these motions have been accomplished, the skids (or front and rear wheels) are on the ground surface and the reactions inherent in absorbing the autorotational landing do not produce a pitching moment. A physical design was developed for the OH-6A and compared to the landing gear provisions of MIL-STD-1290. Ground resonance, weight, and life cycle cost analyses were also performed. The analysis indicates that pitch interconnection significantly reduces the nose-down pitching moment that occurs during nose-high autorotation. This increases blade/tailboom spacing, which eliminates the majority of blade/tailboom strikes. Roll interconnection increases the ground resonance boundaries threefold. (Author)