GB785144A - Improvements in or relating to aircraft arresting gear - Google Patents

Abstract

785,144. Aircraft arresting devices. ACME PRECISION PRODUCTS, Inc. Aug. 15, 1955 [Jan. 13, 1955], No. 23431/55. Class 4. Aircraft arresting gear comprises a pair of supports 8 one each side of a runway, an actuator cable 2 releasably secured at its ends to the supports, an arresting cable 30 lying slack in the runway and releasably secured at its ends to fixed points one each side of the runway, and lifter straps 22 extending between the two cables, whereby when the actuator cable is engaged by a forward part of an aircraft, the arresting cable is flung into the air to engage the aircraft and arrest it. In Fig. 1, the actuator cable 2 is secured to two stanchions 8 through shear pin assemblies 4, shearing at 3,000 lbs. the stanchions being maintained vertical by elastic cords 9. Lifter straps 22 are fastened to the cable 2 and to grommets attached to anchor plates 32 on the runway by devices which separate on a pull of 250 lbs. The arrestor cable 30 is disposed in loops, Fig. 8, formed in the straps 22 by light sewing or snap fasteners as at 24. Each end of the cable 30 is secured to anchor chains 33, Fig. 5, forming drag devices, and is also tied by a cable 78 to a shear pin device 76, shearing at 4,000 lbs., and attached by a cable 74 to the foot of the stanchions 8. Fig. 5 shows the stanchion lying flat on the runway. In operation, the stanchions and actuator strap 2 are raised, and when an aircraft approaches from the right, Fig. 1, the nose wheel engages the cable 2 and taughtens it, breaking the fastening 24 and throwing the cable 30 upwards as shown in Fig. 8 to form an upwardly extending loop in the region of the aircraft which engages the main undercarriage. This loop is part of a tension wave, which propagates along cable 30 and is reflected at each end by the attachment of cable 74 to the stanchion. This reflection ensures that the loop is properly shaped by the time the main undercarriage engages it. Thereafter all shear devices break, and the cable 30 drags the chains 33 to slow the aircraft. In the case of a long cable, intermediate stanchions 40, Fig. 1, are provided, normally maintained upright by elastic cords 64. The actuator cable is attached to a cap 50 on each stanchion, and when the cable 2 is engaged by an aircraft, the cap is raised from the stanchion, this triggering a device releasing the cord 64 so that the stanchion may lie flat on the runway, in case the aircraft should otherwise engage it.