Showing papers on "Landing gear published in 1984"

Aircraft automatic braking system.

Abstract: An aircraft automatic braking system having a signal processor (20) for generating an autobrake valve control current (320) in response to deceleration selection switching means (30), main landing gear air/ground sensing switching means (60), and an inertial reference system (140) to control and limit the level of deceleration produced in the aircraft automatic braking system during the period after landing touchdown on the main gear and prior to nose-gear touchdown.

Aircraft landing gear, in particular for helicopters

Abstract: The landing gear comprises: a rod including nested first and second tubes between which there slides a cylinder whose outer end supports a running gear; a strut surrounding the top of the rod and including a steering mechanism cooperating with a rotary tube disposed between the rod and the strut; and a fluid actuator constituted by at least one chamber between the strut and the rod and having a feed inlet only. The landing gear is particularly applicable to helicopters that are required to "kneel down" camel fashion, e.g., for storage in the hold of an aircraft carrier or a cargo plane.

Warning system for tactical rotary wing aircraft

Abstract: A warning system for rotary wing aircraft that monitors the altitude above ground of the aircraft and issues a warning when there is insufficient terrain clearance. The warning criteria are optimized for rotary wing aircraft and are altered as a function of landing gear position and airspeed. Two distinct warnings are given. One indicates insufficient terrain clearance and the other warns the pilot if he attempts to land with the landing gear up. Logic circuitry is provided to modify the criteria necessary to generate a warning, and to inhibit certain warnings, as required by the mode of operation of the aircraft.

Method and apparatus for controlling braking of an aircraft during landing once the main landing gear has made contact with a runway and before the nose landing gear has made contact

Abstract: The method of controlling aircraft braking during landing on a runway as soon as the running gear of the main landing gear has made runway contact and prior to the nose gear making contact, comprises: determining the value of the nose-up angle Δ of the aircraft as soon as it makes runway contact with its main landing gear; providing a signal representative of the value of the nose-up angle; and controlling braking of the aircraft by any appropriate braking apparatus as a function of a magnitude representative of the signal to ensure acceptable variation of said nose-up angle.

Landing gear for an aircraft structure

Abstract: The low portion (9) of a landing gear strut (3) carrying running means such as a wheel (8) is capable of swivelling together with the running means relative to the strut. A system of cranks (17) receives the necessary force for swivelling the wheel during retraction and extension of the landing gear from a rod (13) which is fixed to the aircraft structure (2) at a point different from the point at which the strut (3) is fixed. The rod (13) is of variable length (piston and cylinder arrangement 31), and the crank system has a stop (33) against excessive swivelling. The arrangement is such that swivelling is restricted to a selected portion of the landing gear's travel, e.g. to ensure that the wheel enters the aircraft body at a particular degree of swivel.

Computer-aided design of the Galaxie landing gear

Abstract: The C-5 landing gear was probably the first landing gear developed by a form of computer-aided design. The sophistication of present-day techniques had not been established at the time of the C-5 study phase, but the various parameters and processes were quite similar.

Short takeoff jump mode for aircraft landing gear struts

Abstract: A telescoping landing gear shock strut set (3, 4, 5) which can provide both the main landing gear and auxiliary landing gear function, and which is affixed to and extendable from an aircraft, is restrained in an unenergized, compressed condition. A high pressure gas charge is then provided between the extendible element (12) of the strut and the element affixed (11) to the aircraft. Early in the takeoff run, the charge gas in the forward strut is released so as to jump the nose and rotate the aircraft to a high: angle of attact appropriate for takeoff. Subsequent to this rotation, but before the conventional takeoff speed is reached, the charge gas in the main strut is released to impart a vertical velocity to the entire aircraft (1), thus jumping into the air. Both the forward strut and main struts incorporate a hydraulic flow bypass function, so that the landing shock absorption function does not compromise the aforesaid energy release, the struts also incorporate values to discharge enough residual gas immediately at the end of the jump stroke so-than the landing energy absorption mode is not compromised. Following the main gear jump, the continuing horizontal acceleration provided by the propulsion engines (10), and continuously weakening vertical acceleration comprising gravity diminished by the wing aerodynamic lift, which is increasing with speed results in an initially upward aircraft trajectory which does not return to earth. A takeoff run with the aforesaid jump action is considerably shorter that the takeoff run without the jump function. Although the jump takeoff speed is less than the conventional takeoff speed, and there would be a lift shortage in a straight flight path, the centrifugal acceleration produced by the bending downward of trajectory, which is initially inclined upward, compensates for this temporary lift shortage.

Negative climb after take-off warning

Abstract: A warning system for aircraft compares the rate of descent of the aircraft with its altitude above ground after take-off, and generates warning if the aircraft is experiencing an excessive descent condition for the radio altitude at which the aircraft is flying. The position of the landing gear, the speed of the aircraft and the engine power are mointored to enable the system only during the take-off or missed approach phases of operation in order to minimize false warnings during other phases. The relationship between radio altitude and descent rate required to generate a warning is optimized for small, high performance aircraft such as fighter or attack aircraft.

Landing gear for amphibious helicopter and aircraft

Abstract: Landing gear for amphibious helicopter and aircraft in which flotation is provided by the fuselage proper, and for which it is necessary to provide transverse balancing, characterised in that it comprises: a main landing gear, articulated onto the fuselage by means of a shaft 22 which is inclined in the horizontal plane and consists of two half-landing gears whose respective leg 14 is provided with a wheel 16 and with a fairing in the shape of a float 18 the capacity of which is defined by the conditions for equilibrium when afloat; a system 24 for controlling the articulation of the main landing gear, in order, starting from the landing position on the ground, to define a position for the wheel and for its fairing which is compatible with the stability conditions when afloat, and to obtain correct incidence of the float when hydroplaning, taking account of the inclination of the said articulation shaft 22; and an auxiliary landing gear, providing steering on the ground, which is provided with a rudder consisting of the fairing of the wheel of this auxiliary landing gear, which, when it is immersed during movement afloat, provides steering for the apparatus.

Braking system and method for a landing airplane in the phase after ground contact of the main landing gear until touch down of the nose wheel.

Abstract: not available for EP0122162Abstract of corresponding document: US4580744The method of controlling aircraft braking during landing on a runway as soon as the running gear of the main landing gear has made runway contact and prior to the nose gear making contact, comprises: determining the value of the nose-up angle DELTA of the aircraft as soon as it makes runway contact with its main landing gear; providing a signal representative of the value of the nose-up angle; and controlling braking of the aircraft by any appropriate braking apparatus as a function of a magnitude representative of the signal to ensure acceptable variation of said nose-up angle.

Validation of an Active Gear, Flexible Aircraft Take-off and Landing analysis (AGFATL)

Abstract: The results of an analytical investigation using a computer program for active gear, flexible aircraft take off and landing analysis (AGFATL) are compared with experimental data from shaker tests, drop tests, and simulated landing tests to validate the AGFATL computer program. Comparison of experimental and analytical responses for both passive and active gears indicates good agreement for shaker tests and drop tests. For the simulated landing tests, the passive and active gears were influenced by large strut binding friction forces. The inclusion of these undefined forces in the analytical simulations was difficult, and consequently only fair to good agreement was obtained. An assessment of the results from the investigation indicates that the AGFATL computer program is a valid tool for the study and initial design of series hydraulic active control landing gear systems.