Drop and Flight Tests on NY-2 Landing Gears Including Measurements of Vertical Velocities at Landing

This investigation was conducted at the request of the Bureau of Aeronautics, Navy Department, to obtain quantitative information on the effectiveness of three landing gears for the NY-8 Consolidated training airplane. The investigation consisted of static, drop, and flight tests on landing gears of the oleo-rubber-disk and the Mercury rubber-cord types, and flight tests only on a landing gear of the conventional split-axle rubber-cord type. The results show that the oleo gear is the most effective of the three landing gears in minimizing impact forces and in dissipating the energy taken. The flight results indicate that in pancake landings with a vertical velocity at contact of 8 feet per second the maximum accelerations experienced are approximately 3.2g, 4.9g, and 4-4g with the oleo, the Mercury, and the split-axle rubber-cord gears, respectively. The results also show that, in the good landings, larger impact forces were experienced subsequent to contact generally less than 2.8g than experienced at contact generally less than 2.0g. The oleo landing gear permitted severe landings to be made without violent rebound, but the Mercury and the split-axle rubber-cord gears caused very violent and dangerous rebounds. A comparison of the results of the drop tests, based upon equal heights of free drops, does not show the relative merits of the landing gears as realized in flight tests. However, a comparison made upon a basis of equal heights of total drop free drop plus vertical movement of the load during the initial stroke of the landing gear is indicative of them.