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Showing papers on "Landing gear published in 1987"


Patent
29 Apr 1987
TL;DR: In this article, a landing gear load sensor for an aircraft (10) having a skid type landing gear (14) is provided, which includes a shear beam (30) with a loadbearing area (40).
Abstract: A landing gear load sensor (24) for an aircraft (10) having a skid type landing gear (14) is provided. The sensor (24) includes a shear beam (30) having a loadbearing area (40). Structure (32, 34) is provided for mounting the shear beam (30) to the aircraft (10), such that the loadbearing area (40) is disposed adjacent the landing gear (14). Structure (50) is disposed on the shear beam (30) between the mounting structure (32, 34) and the loadbearing area (40) for sensing shear load on the shear beam (30).

32 citations


Patent
15 Jul 1987
TL;DR: In this paper, an aircraft ground proximity warning system for undulating or mountainous terrain is presented. But the criteria required to generate the warning is modified when the aircraft is flying over undulating terrain.
Abstract: An aircraft ground proximity warning system (30) having an inadequate terrain clearance warning mode, wherein the criteria required to generate the warning is modified when the aircraft is flying over undulating or mountainous terrain. The system is responsive to signals representative of the radio altitude (hR), the barometric altitude (hB), the speed (34) of the aircraft, the flap position (62) and the landing gear position (68) to provide warnings when the aircraft is operating below a predetermined altitude with either or both of the landing gear or the flaps not in a landing configuration. The warning system also provides a warning when the aircraft is traveling above a predetermined speed and below a predetermined altitude irrespective of the configuration of the landing gear or the flaps.

20 citations


Patent
22 Dec 1987
TL;DR: In this paper, a method and system for reducing stopping distance for an aircraft on a wet runway, which includes blowing away water on a landing surface in front of the aircraft tires so that the tires contact a relatively dry surface and simultaneously blowing air on the tires to remove water that may have collected on them.
Abstract: A method and system for reducing stopping distance for an aircraft on a wet runway, which includes blowing away water on a wet landing surface in front of the aircraft tires so that the tires contact a relatively dry surface and simultaneously blowing air on the tires to remove water that may have collected on them. The system includes ducting from the aircraft engine to the landing gear to receive high pressure air bled from the aircraft engine and nozzles connected to the ducting for exhausting high pressure air to the runway in front of the wheels and to the rear portion of the tires. A system of valves in the ducting can be actuated by switches in the cockpit to bleed high pressure air from the engine to the ducting and nozzles during landing of the aircraft.

17 citations


01 Oct 1987
TL;DR: The Langley Research Center has recently upgraded the landing loads track (LLT) to improve the capability of low-cost testing of conventional and advanced landing gear systems as discussed by the authors, and the unique feature of the Langley Aircraft Landing Dynamics Facility (ALDF) is the ability to test aircraft landing gear system on actual runway surfaces at operational ground speeds and loading conditions.
Abstract: The Langley Research Center has recently upgraded the Landing Loads Track (LLT) to improve the capability of low-cost testing of conventional and advanced landing gear systems. The unique feature of the Langley Aircraft Landing Dynamics Facility (ALDF) is the ability to test aircraft landing gear systems on actual runway surfaces at operational ground speeds and loading conditions. A historical overview of the original LLT is given, followed by a detailed description of the new ALDF systems and operational capabilities.

14 citations



Proceedings ArticleDOI
01 Oct 1987
TL;DR: In this paper, the impact of load and yaw angle on the cornering behavior of the main gear tire of the Space Shuttle Orbiter main gear tires was investigated at the NASA Langley Research Center Aircraft Landing Dynamics Facility.
Abstract: One of the factors needed to describe the handling characteristics of the Space Shuttle Orbiter during the landing rollout is the response of the vehicle's tires to variations in load and yaw angle An experimental investigation of the cornering characteristics of the Orbiter main gear tires was conducted at the NASA Langley Research Center Aircraft Landing Dynamics Facility This investigation compliments earlier work done to define the Orbiter nose tire cornering characteristics In the investigation, the effects of load and yaw angle were evaluated by measuring parameters such as side load and drag load, and obtaining measurements of aligning torque Because the tire must operate on an extremely rough runway at the Shuttle Landing Facility at Kennedy Space Center (KSC), tests were also conducted to describe the wear behavior of the tire under various conditions on a simulated KSC runway surface Mathematical models for both the cornering and the wear behavior are discussed

11 citations


Patent
16 Dec 1987

4 citations


Patent
19 Feb 1987
TL;DR: A semi-trailer of an articulated lorry has rear suspension with trailing arms controlled by air bags as discussed by the authors, and the brakes lock wheels to axles 11 that are fixed to the trailing arms.
Abstract: A semi-trailer of an articulated lorry has rear suspension with trailing arms controlled by air bags. The brakes lock wheels to axles 11 that are fixed to the trailing arms. If the height of the suspension then changes, the wheels may roll along the ground, causing the whole semi-trailer to move forwards or backwards. Landing gear at the front of the semi-trailer has sectional arcuate feet 16 than then roll on the ground, taking up the movement and avoiding high horizontal stresses on the landing gear.

4 citations


01 Sep 1987
TL;DR: In this paper, the ground strike problem was solved by a described technique called anticipation equations, which is a useful tool in the general field of discrete flight simulation and has been used extensively.
Abstract: An aircraft landing may be described as a controlled crash because a runway surface is intercepted. In a simulation model the transition from aerodynamic flight to weight on wheels involves a single computational cycle during which stiff differential equations are activated; with a significant probability these initial conditions are unrealistic. This occurs because of the finite cycle time, during which large restorative forces will accompany unrealistic initial oleo compressions. This problem was recognized a few years ago at Ames Research Center during simulation studies of a supersonic transport. The mathematical model of this vehicle severely taxed computational resources, and required a large cycle time. The ground strike problem was solved by a described technique called anticipation equations. This extensively used technique has not been previously reported. The technique of anticipating a significant event is a useful tool in the general field of discrete flight simulation. For the differential equations representing a landing gear model stiffness, rate of interception and cycle time may combine to produce an unrealistic simulation of the continuum.

2 citations


Patent
26 Oct 1987

1 citations


Journal ArticleDOI
TL;DR: In this article, a conceptual design study was conducted to evaluate the feasibility of a minimum-cost modification of the Lockheed S-3A airframe to an S 3 Vertical Landing (STOVL) configuration.
Abstract: Short Takeoff and Vertical Landing (STOVL) aircraft are options for future replacement of sea-based Conventional Takeoff and Landing (CTOL) aircraft. A conceptual design study was conducted to evaluate the feasibility of a minimum-cost modification of the Lockheed S-3A airframe to an S-3 STOVL configuration. The STOVL concept is based on the use of four TF34 turbofan engines and the application of Lockheed's Advanced Internally Blown Jet Flap/Vectored Thrust (AIBF/VT) hybrid powered-lift system. The S-3 STOVL deck performance estimates are presented along with mission performance comparisons with four CTOL aircraft. These CTOL aircraft are the C-2A, E-2C, S-3A, and KA-6D for the Carrier On-board Delivery, Airborne Early Warning, Antisubmarine Warfare, and tanker missions respectively.

01 Feb 1987
TL;DR: In this paper, a program was conducted to investigate the technical feasibility and practicality of using dynamic scale modeling techniques to design, fabricate, and test a scale model of an aircraft landing gear strut and tire.
Abstract: : A program was conducted to investigate the technical feasibility and practicality of using dynamic scale modeling techniques to design, fabricate, and test a scale model of an aircraft landing gear strut and tire. Dynamic scaling laws were developed and used to design a one-third model of an A-37 Nose Landing Gear (NLG) strut and tire. The A-37 NLG strut and the model gear were tested under dynamically similar conditions of weight, speed, and forcing function on a circular track, Dynamic Test Machine at the Mobility Development Laboratory, Wright-Patterson AFB OH. Comparison of time history data, recorded during each phase of testing, indicated good correlation of the dynamic response of the model landing gear, in relation to the scaling laws and the A-37 NLG dynamic response. Presented in the report is the development and analytical verification of the scaling laws, test data and comparisons, conclusions, and recommendations.

Patent
26 Feb 1987