Showing papers on "Landing gear published in 1968"

Emergency aircraft landing device

Abstract: A landing device for emergency use by aircraft having damaged or inoperable landing gear wherein a vehicle or buggy is propelled along a given path for receiving the aircraft, together with a first cushion system for initially receiving the wing portions of the aircraft and a second cushion system for thereafter receiving the fuselage portions of the aircraft in a transfer operation from the first cushion system.

Retractable main carriage for vertically starting airplanes and airplanes starting on a short runway

Abstract: A retractable main landing gear located behind the center of gravity of the airplane and comprising an adjusting mechanism operable selectively to adjust the landing wheel from a front supporting position, in which the landing wheel is closer to the center of gravity of the airplane, to a rear supporting position, in which the landing wheel is farther away from the center of gravity of the airplane, while the base or area over which the airplane is supported is increased.

An analytical procedure for predicting the two-dimensional impact dynamics of spacecraft landing gear

Abstract: Mathematical prediction model for landing dynamics of impacting struts, and trusses of lunar vehicle landing gear

Some basic guidelines for establishing structural design parameters for the landing gear of stable, soft landing spacecraft.

Abstract: Soft landing spacecraft landing gear design for legged assemblies, discussing load, clearance and stability requirements

Fifty Years of Landing Gear Development: A survey of the pioneering contribution to aircraft undercarriage development made by Vickers and B.A.C. at Weybridge

Abstract: SINCE the original British patent for telescopic oleo‐pneumatic shock absorbers for aircraft landing gear was drawn up in 1915 by Vickers engineer T. S. Duncan — with his invention of the positive recoil damping principle — Weybridge has been in the forefront of landing gear development on all types of aircraft for over half a century. Today, as a member company of British Aircraft Corporation, the Weybridge resources in this field are unique to a prime aircraft manufacturer. The landing gear units for the VC10 and B.A.C. One‐Eleven airliner families and the supporting design, production and testing facilities at Weybridge are among the most advanced in the world.

Aerodynamic Design Features of the C‐5A

Abstract: The C‐5A is designed to provide the capability to transport heavy logistics payloads and outsize military equipment over long ranges for the lowest possible system and operating costs. It provides airport performance and traffic speeds equal to or better than current transports and is capable of operation into and out of short unprepared fields. A general arrangement drawing is shown in Fig. 1. The overall length is 246 ft., the wing span is 222 ft., and the overall height is 65 ft. Of the many missions which the C‐5A must perform, those critical to the design are shown in Tables I and II. The first of these largely defines the high lift system requirements for take‐off and climb performance, the second and third missions dictate the maximum take‐off gross weight for a limit load factor of 2.5 g, and the fourth mission defines the maximum take‐off gross weight for a limit load factor of .25 g. The support area landing distance requirement furnishes an additional constraint on the design of the high lift system. The C‐5A is designed to provide flotation characteristics that will permit 130 take‐offs and 130 landings using short unprepared fields having a California Bearing Ratio of 9. To achieve this flotation a total of 28 wheels, 24 of which form the main landing gear, are used. Stowage provisions for the landing gear constituted a substantial challenge to the aerodynamicist to devise fairings which minimized the penalty which conventional design would accrue. The C‐5A provides the capability of both nose and tail straight in loading at truck bed height in order to achieve a turnaround time of 15 minutes. In addition, it is capable of air dropping both cargo and personnel. These capabilities dictated the use of an upswept aft fuselage which provides clearance for straight in loading. The static ground clearance angle of 10 deg. comfortably exceeds the 7.75 deg. used for lift‐off: the ground clearance angle available with the gear kneeled to place the cargo floor at truck bed height is 7.4 deg. while the maximum ground clearance angle with the gear fully extended is 11.75 deg. The upsweep, or inverse camber, of the aft fuselage introduced the possibility for excessive drag due to the loss of pressure recovery or flow separation in this area. The development of the fuselage configuration to avoid this problem will be discussed in later paragraphs.

Analytical landing gear - soils interaction - phase 1

Abstract: : The determination of aircraft flotation and operation capability on semi- and unprepared soil runways is a critical factor in developing forward area airfields in limited warfare situations. An investigation was conducted to determine the variables which significantly influence aircraft performance when operating on soil runways. Analysis of available experimental drag-sinkage-velocity data led to the defining of at least three distinct regions for which the sinkage ratio-velocity relationship shows a distinct response. A drag ratio-sinkage ratio equation was developed for use in one of these velocity regions. The effects of twin wheel and tandem wheel arrangements were analyzed on a preliminary basis. The results of a sinkage study using presently available sinkage prediction equations indicated that present sinkage analysis accuracy is in the range of plus or minus 50% to plus or minus 100%. In order to develop a suitable flotation criteria, an investigation was conducted of the dynamic landing gear contacting element-soil interaction response utilizing elastic theory. These results led to the development of a flotation parameter (related to sinkage) and a flotation index (related to drag) in nomographic form which permits comparative flotation analysis of landing gear systems.

Evaluation of Aircraft Landing Gear Ground Flotation Characteristics for Operation from Unsurfaced Soil Airfields

Abstract: : This report presents a theoretical method of evaluating aircraft landing gear ground flotation characteristics on unsurfaced soil airfields. Equations developed in AFFDL-TR-66-43, Part I, Aircraft Ground Flotation Investigation, form the basis for the method used in this report. It contains a list of definitions of terms used in regard to ground flotation within ASD and presents a method of evaluating the ground flotation characteristics and capabilities of aircraft to operate from unsurfaced soil airfields. The method presented is relatively straightforward and is applicable to most aircraft having conventional landing gear configurations. A sample calculation is also presented.