AIRCRAFT ARRESTING APPARATUS

• US 3,827,660 A
• Filed: 03/29/1973
• Issued: 08/06/1974
• Est. Priority Date: 12/05/1972
• Status: Expired due to Term

• Current Assignee: Donald B. Doolittle
• Original Assignee: Donald B. Doolittle
• Inventors: Doolittle, Donald B.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Sauberer, Paul E.
• Application Number:
  US05/345,877
• Time in Patent Office: 495 Days
• Field of Search: 244/110,63,11C,11A,11R
• US Class Current: 244/110.00C
• CPC Class Codes: B64F 1/027 using net or mesh

Abstract

A compound array of vertically deployed open loops of strong inelastic webbing having a maximum dimension slightly smaller than the wingspan of the aircraft to be arrested are detachably hung from a suspension line stretched above and across the runway. The array includes a number of laterally overlapped net elements which present enough loops to seucrely engage and restrain an aircraft which penetrates any portion of the barrier. Slide connectors attach lower portions of the loops to a rearwardly deployed cross runway pendant connected between a pair of energy absorbing devices. When an aircraft impinges upon the barrier, the loops break away from the suspension line and freely move to engage the stronger larger dimensional portions of the aircraft from behind and below it. The loops are conveniently deployed in a pentagonal configuration with their peaked tops connected to the suspension line, their sides breakably connected to each other and bottoms attached by slide connectors to a steel cross runway pendant, which can be optionally used for hook arrestment when the barrier is lowered. The nose wheels pass over and clear the cross runway pendant before the aircraft engages the deployed barrier and its pendant anchored loops, which pull upwardly upon the pendant. The slide connectors are capable of considerable elongation without breaking when a predetermined force exceeding a safe holding force for their attached loops engaged aircraft portion is applied to them. When the elongation brings a sufficient number of loops into engagement, the connectors stop elongating and hold, thus applying substantially safe balanced restraint upon the engaged portions of the aircraft. The elongation is accomplished by stitched folded straps of an unyielding material or by use of a yielding material such as undrawn nylon or a low modulus of elasticity metal, such as annealed stainless steel. The elongatable or extensible connectors are assembled from disconnectable parts to facilitate removal and replacement after permanent distortion. The pendant is coated with an antifriction polymeric material to facilitate lateral sliding adjustment of the connectors and loops.

Claims

1. An aircraft arresting barrier for an airport runway having an energy absorbing device installed alongside comprising a flexible horizontal linear component for disposition across and adjacent the surface of said runway, connecting means for attaching said horizontal linear component to said energy absorbing device, an array of flexible aircraft arresting loops for disposition in a network across said runway in the path of a landing aircraft, each of said loops being large enough to permit free passage of protruding portions of said aircraft and small enough to engage larger dimensional portions of said aircraft when said aircraft impinges upon said barrier device, a suspension line for disposition across said runway a predetermined distance above the vicinity of said horizontal cross runway linear component, separable ties connecting said loops to said suspension line and to each other whereby said loops are vertically deployed in a network across said runway in position to be engaged by said aircraft, connectors attaching lower portions of said loops to said horizontal cross runway linear component to allow said loops to engage larger dimensional and stronger portions of said aircraft and to apply the restraint of said energy absorbing device to said stronger portion of said aircraft from behind and below it, and said connectors being constructed and arranged to be capable of elongating without breaking above a predetermined individual loading on initially stressed loops and of holding after a sufficient number of loops are engaged to share the applied load and reduce said individual loading below said predetermined loading whereby the loops are caused to exert substantially balanced and non-damaging restraint upon the portions of the aircraft which they engage.

2. An aircraft arresting barrieR as set forth in claim 1 wherein said horizontal cross runway linear component is a single cross runway pendant.

3. An aircraft arresting barrier as set forth in claim 1 wherein said connectors comprise undrawn nylon.

4. An aircraft arresting barrier as set forth in claim 3 wherein said undrawn nylon has a characteristic of percentage of elongation versus percentage of breaking strength having a relatively flat intermediate portion, and said undrawn nylon being constructed and arranged to cause said relatively flat intermediate portion to have a breaking strength which is approximately 15-20 percent of that of the material of the loop to which each of said connectors is attached.

5. An aircraft arresting barrier as set forth in claim 1 wherein said connectors comprise stitched folded straps.

6. An aircraft arresting barrier as set forth in claim 5 wherein said stitched folded straps have a maximum of three stitched layers.

7. An aircraft arresting barrier as set forth in claim 5 wherein said straps comprise a material having a relatively high modulus of elasticity.

8. An aircraft arresting barrier as set forth in claim 7 wherein said straps comprise a polyester.

9. An aircraft arresting barrier as set forth in claim 5 wherein the stitched folded straps are constructed and arranged to break and unfold at a stress approximately 15-20 percent of the breaking strength of the material for said loops, and the breaking point of each of said stitched folded straps slightly varying from each other.

10. An aircraft arresting barrier as set forth in claim 9 wherein the breaking point of said stitched folded straps varies approximately 10 percent from each other.

11. An aircraft arresting barrier as set forth in claim 1 wherein said connectors include a disconnectable pair of open ended connector elements for facilitating installation and replacement of elongated connectors.

12. An aircraft arresting barrier as set forth in claim 11 wherein each of said disconnectable pair of open ended connector elements includes straps, and said straps having stitched folds for varying their length under applied force.

13. An aircraft arresting barrier as set forth in claim 12 wherein the open ends of said pair of connector elements incorporate securing means for connecting said open ends to each other.

14. An aircraft arresting barrier as set forth in claim 13 wherein said securing means comprise closed loops on said ends whereby said ends may be interwoven and locked together.

15. An aircraft arresting barrier as set forth in claim 11 wherein said connectors have slide connections and said slide connections have a slit side to facilitate replacement on said cross runway linear component and said loops.

16. An aircraft arresting barrier as set forth in claim 1 wherein said cross runway linear component has a coating of an antifriction material.

17. An aircraft arresting barrier as set forth in claim 16 wherein said antifriction material comprises a tough slippery polymeric material.

18. An aircraft arresting barrier as set forth in claim 1 wherein said horizontal linear component comprises a steel cable and said connectors comprise stitched folded straps.

19. An aircraft arresting apparatus for an airport runway having an energy absorbing device installed alongside comprising a flexible horizontal linear component for disposition across and adjacent the surface of said runway, connecting means attaching said horizontal linear component to said energy absorbing device, an array of flexible aircraft arresting elements for disposition in a network in the path of a landing aircraft, a suspension line for disposition across and above said runway, said aircraft arresting elements being attached to said suspension line for vertically deploying them across said runway in position to be engaged by said aircraft, connectors attaching lower portions of said aircraft arresting elements to said horizontal cross runway linear component for applyiNg the restraint of said energy absorbing device to said aircraft arresting elements when they are engaged by a landing aircraft, and said connectors being constructed and arranged to be capable of elongating without breaking above predetermined individual loading on initially stressed aircraft arresting elements and of holding after a sufficient number of aircraft arresting elements are engaged to share the applied load and reduce said individual loading below said predetermined loading whereby said aircraft arresting elements are caused to exert substantially balanced and non-damaging restraint upon the portions of the aircraft which they engage.

20. An aircraft arresting apparatus as set forth in claim 19 wherein each of said connectors comprises a disconnectable pair of open ended connector elements for facilitating installation and replacement of elongated connectors.

21. An aircraft arresting apparatus as set forth in claim 20 wherein each of said disconnectable pair of open ended connector elements includes straps, and said straps having stitched folds for varying their length under applied force.

22. An aircraft arresting apparatus as set forth in claim 21 wherein the open ends of said pair of connector elements incorporate securing means for connecting said open ends to each other.

23. An aircraft arresting apparatus as set forth in claim 22 wherein said securing means comprise closed loops on said ends whereby said ends may be interwoven and locked together.

24. An aircraft arresting apparatus as set forth in claim 19 wherein said connectors comprise stitched folded straps.

25. An aircraft arresting apparatus as set forth in claim 24 wherein said stitched folds are constructed and arranged to break and unfold at a stress approximately 15-20 percent of the breaking strength of the material for said aircraft arresting elements and the breaking point of each said folds slightly varying from each other.

26. An aircraft arresting apparatus as set forth in claim 25 wherein the breaking point of said stitched folds varies approximately 10 percent from each other.

27. An aircraft arresting apparatus as set forth in claim 19 wherein said connectors comprise undrawn nylon.

28. An aircraft arresting apparatus as set forth in claim 27 wherein said undrawn nylon has a characteristic of percentage of elongation versus percentage of breaking strength having a relatively flat intermediate portion, and said undrawn nylon being constructed and arranged to cause said relatively flat intermediate portion to have a breaking strength which is approximately 15-20 percent of that of the material of the loop to which each of said connectors is attached.

29. An aircraft arresting apparatus as set forth in claim 19 wherein said cross runway linear component comprises a single cross runway pendant.

30. An aircraft arresting apparatus as set forth in claim 29 wherein said suspension line is supported by movable stanchions which are erected to deploy said network in the path of a landing aircraft and dropped to activate said linear component for hook arrestment.