Aircraft arrestment system

A method for controlling the magnitude and timing of tensile-load increases in a flexible linear element anchored at both ends which is impacted by a moving body causing the propagation of longitudinal tensile loads and transverse waves comprising:

• shaping the element into two mirror image curved portions each located about equidistant from the point of impact by drawing the element against stationary support members;
• providing said element with longitudinal freedom of movement and transverse freedom of movement in the direction of impact;
• and,
• allowing passage of the longitudinal tensile loads while partially reflecting the transverse waves formed at impact with each support member.

A method of stopping an aircraft landing on a runway comprising:

• A. placing apart a first pair of stationary cable support members on the runway with each member being equidistant from opposing sides of the aircraft landing path in a plane perpendicular thereto, the distance between each member sufficient to allow safe and effective passage of the aircraft;
• B. placing apart a second pair of stationary cable support members on the runway with each member being equidistant from opposing sides of the aircraft landing path in a plane perpendicular thereto, the distance between each member of said second pair being greater than the distance between said first pair of support members with the second pair being horizontally offset from said first pair in a direction opposite to the direction of aircraft movement;
• C. locating each member of the second pair from the adjacent respective member of the first pair to allow partial reflection of a transverse wave moving along a cable positioned thereagainst;
• D. drawing a cable taut against each of the support members on the side thereof toward the direction of aircraft movement;
• E. attaching each end of the cable to a fixed energy absorbing device located on opposing sides of the runway;
• F. engaging the cable with engagement means from the aircraft as it lands on the runway causing the propagation of transverse waves in the cable;
• G. partially reflecting the transverse waves at each support member to moderate the initial cable tensile-load increase;
• and,
• H. absorbing the moderated tensile-load with the energy absorbing device and stopping movement of the aircraft.