The present invention relates to aviation and more particularly to airport runway surfaces.
Some smaller airfields are known to have natural grass surfaces. Those airfields experience each of the same problems growing and maintaining grass that exist in any type of natural grass setting. For example, grass in such fields can die for a myriad of reasons, leaving muddy ground that becomes rutted or heaved due to moisture. The ground can also dry to the point of creating foreign object debris (“FOD”) problems for aircraft. Such natural grass surfaces require watering and feeding, which is time consuming and expensive. Moreover, such natural surfaces provide food and nesting materials for birds and other animals, which are generally unwelcome around aircraft.
Besides the natural hazards to maintaining natural grass, the impact of aircraft exacerbates the degradation of the natural surface. Aircraft landing in wet, muddy and/or bare areas can further rut or heave the natural surface. Moreover, the force created by the aircraft landing gear can destroy the natural grass, especially in conditions where such grass is not healthy or in areas where the root structure of the natural grass is not particularly strong. Such areas can become rutted or heaved as well, making landing thereon difficult
Many airstrips that should have irrigation and drainage systems do not have such systems. Moreover, installing such systems incurs cost. Those airstrips over time can become uneven, rutted, heaved and otherwise unsuitable for landing. Eventually the airstrip reaches a level where landing is not safe. At that point, while it may be more economical in the short term to tear out the existing natural grass, regrade the landing strip and thereafter replant new seed or sod, such remedy only begins anew the cycle of natural grass degradation. The same areas which had previously shown problems growing or sustaining grass growth will likely once again experience such problems due the environment and aircraft impact, especially in situations where the airstrip is not properly watered and drained.
A need therefore exists for an economic, rugged and readily implemented system for replacing natural turf surfaces at airstrips and airfields.
The present invention includes a system, apparatus and method for installation of an artificial or synthetic turf or covering at airfields or airstrips in place of natural grass airstrips. The terms “artificial turf”, “artificial grass”, “synthetic turf” and “synthetic grass” are used herein interchangeably. Each of those terms refers to the commonly understood artificial turf having a backing with tufted or stitched synthetic grass blades extending therefrom. Those terms also expressly encompass other types of synthetic surfaces, such as synthetic matting, porous plastic and/or rubber materials, and plastic and/or rubber fabrics.
In one preferred embodiment, the surface is made to look like grass and provides an aesthetically pleasing airstrip when installed. The artificial turf can include runway border indicia, any known runway symbol or marking, advertising, logos, airport names, institutional names and any combination of same. The artificial turf runway system can be installed adjacent to any type of concrete, asphalt or other manmade structure, such as a roadway, paved runway, paved taxiway, parking lot, building, etc., or be surrounded completely by natural grass, shrubs, trees, etc.
The turf is installed securely using a number of apparatuses and methods discussed herein, such as via pinning devices, glue, masking, or other adhesive, which each attach the turf to a beam or header, which itself is securely installed to an anchor, such as a concrete anchor. Otherwise, the turf can be supported in its middle sections via those securing apparatuses or via the weight of infill applied to the turf.
The base beneath the turf is compacted, e.g., to greater than 90% compaction and in one preferred embodiment to greater than 95% compaction. The base in one embodiment is crushed rock of different size particles, which are capable of being compacted to a greater extent than, for example, rolled rock or rock particles of the same size.
The crushed stone and compacted base are well-suited for supporting aircraft taking off and landing from the synthetic strip of the present invention. As used herein, the term “aircraft” refers to gliders, any type of small airplane, such as single engine, multi-engine, turbo-prop, bi-plane or tri-plane. It is also possible that the depth of the compacted base could be deep enough to support the weight of a large jet airliner taking off and landing thereon. The term “aircraft” therefore includes larger jet airplanes, as well as other types of aircraft, such as helicopters, hot air balloons, etc. As used herein, “aircraft” also refers to any type or size or unmanned aerial vehicle (“UAV”). These aircraft examples are in no way meant to limit the scope of the invention or to serve as any sort of disavowal or disclaimer.
The turf system is graded so that water flows outwardly towards one or more edges of the system. The artificial turf does not require watering, seeding or separate drainage but instead requires only infrequent maintenance of the system to remove weeds and other sparse grass that may grow through the compacted base. The artificial turf runway therefore provides a stable, lasting, aesthetically pleasing and highly functional landing and takeoff area for aircraft.
The artificial turf surface also removes food and nesting materials for birds and other animals over a relatively large area, tending to dissuade those birds and animals from entering and loitering on the turf system. Further still, the artificial turf, which in one preferred embodiment is made of polypropylene, is fire and bum resistant, and therefore tends to mitigate a fire spreading from an aircraft accident occurring on the system. Still further, the sand or other infill layer tends to absorb noise and engine fuel, which lessens the noise disturbance from propeller engines, turbo-propeller engines or jet engines and reduces accident fires, respectively. Further still, the artificial turf system provides an all-weather structure that can be traversed in rainy or snowy conditions by safety and maintenance vehicles without obstruction.
It is therefore an advantage of the present invention to provide an artificial turf runway system and surface for small, medium and large aircraft.
It is another advantage of the present invention to reduce the possibility of bird strikes and accidents caused by other animals.
It is a further advantage of the present invention to minimize the fuel and fire damage from an aircraft accident.
Moreover, it is an advantage of the present invention to provide a synthetic turf system that reduces noise.
Further still, it is an advantage of the present invention to provide an artificial turf system that provides an all-weather, stable apparatus for emergency and safety vehicles.
Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the figures.
The present invention provides an artificial turf runway surface suitable for supporting takeoff, landing and taxiing of aircraft as that term has been described herein. The turf system cures many of the problems and pitfalls associated with natural grass systems, such as rutting, bare spots, unevenness, standing water as well as other problems associated with natural grass surfaces. The synthetic surface also removes nesting materials and food and thereby dissuades birds and other animals from landing and congregating thereon.
Referring now to the drawings and in particular to
Further, while artificial turf is used in one preferred embodiment, the present invention is expressly not limited to artificial grass, but can instead use any type of synthetic matting, which for example can be porous or perforated. The “turf” specified by element number 12 also includes synthetic coverings that are made of a combination of plastic and rubber, which are bound together in a granulated fashion, and which allow water and moisture to percolate through same.
Artificial turf 12 in one embodiment is green but can have any other color or be of a multitude of colors, any one or more of which can be fluorescent. Turf 12 includes and defines multiple different types of painted-on, sown-in or integral markings, such as runway borders 14, which divide the entire area of turf 12 into multiple runways. The turf markings also include any known type of airport or runway marking, such as the chevron markings 16 shown in
Artificial turf 12 also displays other types of markings, such as advertising 18, logos 20, airport names 22, institution names 24 (such as a university name, a company name, a military organization, etc.) and any combination thereof. The present invention expressly contemplates subsidizing the cost of the artificial turf system 10 to the end user by displaying advertising 18 and obtaining revenue from one or more advertisers. Such advertising and revenue can be used to lower the cost of the system 10 to the end user. Advertising can also yield licensing and/or lease fees, which can be paid to either the system installer or to the end user. Thus, system 10 can provide each of the operational and functional advantages described herein as well as provide an ongoing revenue stream to the system supplier and/or the end user.
As illustrated in
System 10 is adaptable to provide virtually any size artificial runway surface, which can be used for one or more aircraft runways. One example for the width and length of turf 12 is a width “w” of 500 feet and a length “l” of 4,500 feet. It should be appreciated however that such numbers are only an example, and the area of turf 12 can be larger or smaller as desired. The area of turf 12 as illustrated shows four separate runways, which can be evenly spaced apart to allow multiple aircraft 30 to land, taxi and/or park on artificial turf surface 12. System 10 is also suitable to be used as a taxiway that may or may not be implemented in combination with a runway.
Referring now to
A compacted rock or crushed rock base 36 is applied on top of weed barrier 32. Each of the embodiments for the base described in U.S. Pat. No. 6,620,482 is suitable for use in the present invention. The depth of the base 36 in one embodiment is one to twenty inches or deeper. For lighter aircraft, such as gliders, the thickness of the compacted base 36 is in one embodiment about two to three inches and consists of quarter inch minus road base, which is crushed rock having a diameter of about one quarter inch down to rock that has virtually a zero diameter, e.g., sand or dust. The different sized particles enable base 36 to be compressed to a more compacted state than if rolled rock or rock of approximately the same size diameter particulate is used. Such rolled and similarly sized particles create interstices regardless of how much pressure is applied to compact those materials. The quarter inch minus base 36 on the other hand can be compacted to greater than or equal to 90% (less than or equal to 10% air), in one embodiment greater than or equal to 95%, and it may even approach or surpass a 99% level of compaction.
A second weed barrier 32 or sheeting membrane 38 is applied in one embodiment on top of compacted base 36. Upper geo-textile 32 or other suitable fabrics, like lower layer 32, enable water to permeate through same but does not enable weeds, plant life and other vegetation or insects from growing or moving from base 36 and out through turf 12. Alternatively, a substantially water impermeable membrane 38, such as a plastic sheet, is applied on top of base 36 instead of the second weed barrier 32.
The surface of soil or sand 34 and each of the layers applied thereon are graded to a desired slope, such as a 2% slope, which enables water to drain to a desirable area. In
Water that does flow through matting 42 will tend to flow along the top of impermeable membrane 38 or substantially along the top of the compacted base 36. Some of the water eventually flows through compacted base 36. Water that reaches weed barrier 32 is allowed to flow eventually into compacted surface 34. It should be appreciated however that system 10 is configured to mainly move water along the graded surfaces to a desired location within or on the exterior of system 10, which includes suitable drainage that carries water away from the runway, taxiway, etc. System 10 does not require elaborate drainage, which is advantageous from a cost and feasibility standpoint.
For lighter aircraft, such as gliders and UAV's, base 36 can be less substantial. It is expressly contemplated for example to create a quick but functional landing and take-off area for a UAV by simply clearing an area of debris and rolling out a length of turf 12 on the cleared area. The area could be a dirt area or a sand or dessert area. Grass could be removed from the dirt or left beneath turf 12. In any case, the cleared area may or may not be compacted depending on the size of the aircraft and immediacy of the need for a functional airstrip. Different strips of turf 12 can be quickly stitched or glued together to provide a landing strip with a desired length and width.
Turf 12 in one embodiment has a pile height of approximately one-half inch to six inches. In one preferred embodiment, the pile height is about two inches. The sand infill 40 is compacted to about 1⅜ inches to about 1¾ inch in one embodiment. While pure sand is preferred in one embodiment, it should be appreciated that some percentage or all of the infill 40 can be comprised of other materials, such as granulated rubber and/or cryogenically ground rubber particles. It may be desired that a partial or full rubber infill be used in some instances to provide a softer landing. To that end, some or all of the base 36, depending on the size and weight of the intended aircraft, can be of a softer and more compressible material such as sand and/or rubber.
The spacing of the fibers 44 is provided in straight or curves rows, which can be spaced apart from about ¼ inch to about 2½ inches. In one preferred embodiment, the fibers 44 extend past the infill layer 40 a distance of about ⅛ inch to two or more inches. The extension of the fibers 44 over the infill layer 40 helps to prevent sand or other infill 40 particles from flying up into a jet, propeller or turbo-prop engine. Further, the extended pile height prevents sand or other infill type from being dragged up and from being blown or gusted up via ambient wind, becoming a FOD.
In an alternative embodiment, infill 40 is not employed. Such application could allow a relatively inexpensive turf 12 having a short pile height, e.g., one-half inch to be employed. Removing the infill may be desirable if the infill is seen as potentially providing a FOD. It is believed however that the sand or other infill compacts further over time, reducing a likelihood of the infill being kicked-up as an aircraft rolls over turf 12 and system 10. In a further alternative embodiment, infill 40 may include a stabilizer, such as polymer fibers placed within the sand or other infill particles.
Referring now to
Referring now to
The attachment system includes a plurality of anchors 50, which are imbedded into soil or sand 34 a suitable distance to provide a secure mounting structure for the edge of turf 12 of system 10. Anchors 50 in one embodiment are concrete anchors, such as eight inch diameter anchors. Alternative anchors 50 are square or rectangular and are made of any suitable material, such as composite plastic, asphalt, metal, or wood. Concrete is desirable in one embodiment because a hole or trench can be dug, wherein the concrete is poured to a desired depth, width and shape.
Anchors 50 can be poured to a depth of about six inches to about six feet or deeper as needed. In one embodiment, the anchors 50 are poured to about two feet. Anchors 50, as shown in
Anchors 50 have embedded studs 54 that extend from an end of the anchors.
The concrete anchors 50 as well as the side of manmade structure 26 in one embodiment are saw cut to provide a flush and even surface for abutting against headers 52. Anchors 50 are saw cut (around studs 54) to create level supports as seen in
Glue or mastique can be used in a number of places in system 10 to help secure turf 12 to, for example, upper weed barrier 32 or membrane 38. Further, mastique or glue can be applied between barrier 32/member 38 and the backing of turf 12 or between barrier 32/member 38 and header 52. Other devices are also used to secure of turf 12 to base 36 and soil or sand 34. For example, U-shaped staples 58 or T-shaped pinning devices 60 can be hammered through turf 12 into base 36 and potentially through base 36 into soil or sand 34. Either the staples 58 or the pinning devices 60 can include ribbed apparatuses 62 that help prevent pinning devices 60 or staples 58 from dislodging from the materials to which they are attached.
Referring now to
The system is particularly well-suited for gliders and the present invention expressly contemplates a method for allowing gliders to take off and land on a synthetic turf runway.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 60/519,572, filed Nov. 12, 2003, entitled “Synthetic Runway Surface System”, the entire contents of which are hereby incorporated by reference and relied upon.
Number | Name | Date | Kind |
---|---|---|---|
3625011 | Stevenson | Dec 1971 | A |
3664241 | Blackburn | May 1972 | A |
3687021 | Hensley | Aug 1972 | A |
3735988 | Palmer et al. | May 1973 | A |
3935352 | Toland | Jan 1976 | A |
3967704 | Ogden | Jul 1976 | A |
3968041 | De Voss | Jul 1976 | A |
3995079 | Haas, Jr. | Nov 1976 | A |
4011022 | Welty | Mar 1977 | A |
4044179 | Haas, Jr. | Aug 1977 | A |
4047491 | Spanel et al. | Sep 1977 | A |
4067757 | Layman | Jan 1978 | A |
4152473 | Layman | May 1979 | A |
4216735 | McDaniel, Jr. | Aug 1980 | A |
4312504 | Rutledge et al. | Jan 1982 | A |
4337283 | Haas, Jr. | Jun 1982 | A |
4381622 | Spidell | May 1983 | A |
4396653 | Tomarin | Aug 1983 | A |
4462184 | Cunningham | Jul 1984 | A |
4489115 | Layman et al. | Dec 1984 | A |
4497853 | Tomarin | Feb 1985 | A |
4637842 | Jeffrey et al. | Jan 1987 | A |
4662778 | Dempsey | May 1987 | A |
4755401 | Friedrich et al. | Jul 1988 | A |
4948116 | Vaux | Aug 1990 | A |
5205068 | Solomou | Apr 1993 | A |
5206058 | Fry et al. | Apr 1993 | A |
5303523 | Hand et al. | Apr 1994 | A |
5392723 | Kaju | Feb 1995 | A |
5439968 | Hyche | Aug 1995 | A |
5489317 | Bergevin | Feb 1996 | A |
5586408 | Bergevin | Dec 1996 | A |
5672352 | Clark et al. | Sep 1997 | A |
5850708 | Bergevin | Dec 1998 | A |
5902414 | Keal et al. | May 1999 | A |
5932357 | Coates et al. | Aug 1999 | A |
5958527 | Prevost | Sep 1999 | A |
5976645 | Daluise et al. | Nov 1999 | A |
5986551 | Pueyo et al. | Nov 1999 | A |
6039767 | Boyes et al. | Mar 2000 | A |
6048282 | Prevost et al. | Apr 2000 | A |
6132137 | Gunter | Oct 2000 | A |
6216389 | Motz et al. | Apr 2001 | B1 |
6277989 | Chakravarty et al. | Aug 2001 | B1 |
6620482 | Carr et al. | Sep 2003 | B2 |
6723412 | Prevost | Apr 2004 | B2 |
6794007 | Carr et al. | Sep 2004 | B2 |
6946181 | Prevost | Sep 2005 | B2 |
7175362 | Carr et al. | Feb 2007 | B2 |
20020064628 | Carr et al. | May 2002 | A1 |
20020146519 | Carr et al. | Oct 2002 | A1 |
20030092531 | Daluise | May 2003 | A1 |
20030182855 | Prvost | Oct 2003 | A1 |
20030215287 | Prevost | Nov 2003 | A1 |
20040058095 | Carr et al. | Mar 2004 | A1 |
20040058096 | Prevost | Mar 2004 | A1 |
20040146352 | Carr et al. | Jul 2004 | A1 |
20050031803 | Prevost | Feb 2005 | A1 |
20050129903 | Carr et al. | Jun 2005 | A1 |
20060088380 | Prevost | Apr 2006 | A1 |
20070098925 | Daluise | May 2007 | A1 |
20080032069 | Carr et al. | Feb 2008 | A1 |
20100028078 | Carr et al. | Feb 2010 | A1 |
20100030709 | Carr | Feb 2010 | A1 |
Number | Date | Country |
---|---|---|
1182485 | Feb 1985 | CA |
1226313 | Sep 1987 | CA |
1235160 | Apr 1988 | CA |
2043170 | Nov 1992 | CA |
2095158 | Oct 1994 | CA |
2218314 | Sep 1998 | CA |
2206106 | Dec 1998 | CA |
2206295 | Dec 1998 | CA |
2294071 | Dec 1998 | CA |
2294096 | Dec 1998 | CA |
2238953 | Nov 1999 | CA |
2247484 | Mar 2000 | CA |
3901392 | Jul 1990 | DE |
WO 0215161 | Feb 2002 | WO |
WO 0220903 | Mar 2002 | WO |
Number | Date | Country | |
---|---|---|---|
20050129903 A1 | Jun 2005 | US |
Number | Date | Country | |
---|---|---|---|
60519572 | Nov 2003 | US |