AN AIRCRAFT ARRESTER
Filed of Invention:
The present invention relates to a decelerator system, particularly, the present invention relates to a mechanical system used for stopping a fast moving vehicle, more particularly the present invention relates to a system for stopping an aircraft during emergency condition.
Background of the invention:
To decelerate an aircraft in an emergency condition many systems are used worldwide. Their engagement system is either a steel cable or a flexible net.
Two energy absorbers are installed at either side of runway on a fixed foundation or energy absorber mounting on a trailer having temporary foundation. As the aircraft engages with the engagement system the flexible tape unwound from tape drum which results the rotation of tape drum the shaft of the tape drum is connected with a brake unit which will give a resisting torque the energy will be absorbed with the help of braking mechanism and aircraft traveled to a safe stop.
The document WO 20051021378 A2 describes a low profile brake-in-spool aircraft arresting system. The system described in this document is having friction brake type energy absorbers and can be used for hook type of aircrafts only and having tape spools, which are configured for one time use only. The arrester system disclosed in the document (WO 20051021378 A2) involved the following features:
• four friction brake type energy absorbers are used;
• only hook type aircraft can be engaged with the barrier;
• in this system tape spools are configured for one time use, tape spool will be replaced for next engagement;
• tape connector used in this system is having three arms in which two purchase tapes are connected in one side and retractable cable is connected in other side;
• two purchase tapes are passing from one sheave assembly;
• pressure roller is having different configuration.

The US Patent US 150370 describes a method and apparatus for restoring the retractable barrier of an aircraft arrester. The document (US 150370) discloses only for rewinding technology of purchase tape after arrestment of aircraft.
Objects of the present invention:
The main object of the present invention is to provide a mechanical decelerator system. Another object of the present invention is to provide an aircraft arrester. Still another object of the present invention is to provide an improved braking system for fast moving vehicle more precisely to decelerate or stop a fighter aircraft during emergency condition in the event of aborted take off or landing over run with minimal damage to aircraft or injury to the crew.
Summary of the present invention:
The present invention contemplates with the method of absorbing the energy of the fighter aircraft in case of emergency. The present invention provides an arrester for better arresting i.e. decelerating and stopping the fast moving vehicle. Particularly, the arrester disclosed in the present application can be used for decelerating and stopping the aircrafts.
Statement of invention:
Accordingly, the present invention relates to an aircraft arrester comprising:
a barrier comprising a multiple element net (MEN) assembly placed across a runway; said
barrier is movable from a folded position, which is in direction generally parallel to a runway
to an erected position, which is intercept path of the aircraft to envelop the aircraft;
a means for positioning the barrier comprising a pair of stanchions placed across the runway;
the stanchions are movable from a folded position, which is generally parallel to a runway to
an erected position, which is generally perpendicular to the runway;
a means for detachably engaging the MEN assembly with the stanchions;
at least one connection link connecting one end of a tape with the MEN assembly; other end
of the tape is wound on a tape drum;
an electrical control system comprising a motor, a limit switch unit and an electronic timer to
control the movement of the barrier from the foldable position to the erected position and to
control the movement of the barrier from erected position to the folded position;
an energy absorber unit connected with the tape drum for absorbing the kinetic energy of the
aircraft as the tape plays out following engagement of the aircraft with the MEN assembly.

Brief description of drawings:
Figure 1 illustrates an aircraft arrester according to an embodiment of the present invention.
Figure 2 shows assembly of the energy absorber of the aircraft arrester according to an
embodiment of the present invention.
Figure 3 is a view of components of the energy absorber shown in figure 8 according to an
embodiment of the present invention.
Figure 4 shows sheave pulley of the aircraft arrester according to an embodiment of the
present invention.
Figure 5 shows a tape retrieval system of the aircraft arrester according to an embodiment of
the present invention.
Figure 6 shows of multi-stage gear mechanism of electric motor of the aircraft arrester
according to an embodiment of the present invention.
Figure 7 shows limit switch of the electrical control system of the aircraft arrester according
to an embodiment of the present invention.
Figure 8 illustrates Radio Command System of the aircraft arrester according to an
embodiment of the present invention.
Figure 9 is an exemplary illustration of an illuminating device for aircraft arrester according
to an embodiment of the present invention.
Figure 10 shows a variable orifice type hydraulic shock absorber for aircraft arrester
according to an embodiment of the present invention.
Fig. 11 is shows constructions of wire ropes of the aircraft arrester in accordance of an
embodiment of the present invention.
Detailed description of the present invention:
Accordingly, the present invention provides an aircraft arrester comprising:
a barrier comprising a multiple element net (MEN) assembly placed across a runway; said
barrier is movable from a folded position, which is in direction generally parallel to a runway
to an erected position, which is intercept path of the aircraft to envelop the aircraft;
a means for positioning the barrier comprising a pair of stanchions placed across the runway;
the stanchions are movable from a folded position, which is generally parallel to a runway to
an erected position, which is generally perpendicular to the runway;
a means for detachably engaging the MEN assembly with the stanchions;
at least one connection link connecting one end of a tape with the MEN assembly; other end
of the tape is wound on a tape drum;

an electrical control system comprising a motor, a limit switch unit and an electronic timer to control the movement of the barrier from the foldable position to the erected position and to control the movement of the barrier from erected position to the folded position; an energy absorber unit connected with the tape drum for absorbing the kinetic energy of the aircraft as the tape plays out following engagement of the aircraft with the MEN assembly.
In an embodiment of the present invention the limit switch unit comprises a rear limit switch configured to co-operate with the electronic timer to control flow of power to the motor during movement of the barrier from folded position to the erected position.
In another embodiment of the present invention the limit switch unit comprises a front limit switch configured to co-operate with the electronic timer to control flow of power to the motor during movement of the barrier from erected position to the folded position.
In still another embodiment of the present invention electrical control system comprises an override switch configured to stop flow of power to the motor upon failure of rear limit switch and timer.
In yet another embodiment of the present invention the MEN assembly is provided with bottom strap and anchoring means to anchor the MEN assembly on the runway to preventing the MEN assembly from drifting due to wind pressure/ aircraft exhaust.
In a further embodiment of the present invention the means for detachably engaging the MEN assembly with the stanchions comprises a suspension cable, a shear-off coupling, lifting-pulling machine, restraining cable assembly and suspension cable anchor.
In a further more embodiment of the present invention the means for positioning the barrier comprises electrically operated winch device for moving the stanchion from the folded position to the erected position and from erected position to the folded position.
In another embodiment of the present invention the connection link comprises a 'C shaped weldment and a shaft.

In still another embodiment of the present invention the tape is a woven nylon belt with ultraviolet resistant treatment.
In yet another embodiment of the present invention the energy absorber unit comprises a hydraulic braking device coupled to the tape drum.
In a further embodiment of the present invention the energy absorber unit is provided with pressure roller assembly for maintaining the pressure of the tape against the tape drum.
In a further more embodiment of the present invention the tape is guided by (a) an absorber sheave, which guides the tape on and off the tape drum; and (b) a runway sheave, which minimizes the tape sweep area and enables the tape to play out in a well defined direction.
In another embodiment of the present invention the electrical control system comprises a tape retrieval system.
In still another embodiment of the present invention the electrical control system comprises a main control panel located at the runway site a remote control panel of a radio command system for controlling the electrical operation of moving the barrier from the folded position to the erected position and from the erected position to the folded position.
In one more embodiment of the present invention the radio command system comprises a slave unit, located in the main control panel of the electrical control system and master unit located at a location remote from the main control panel.
Detailed description of embodiments Before describing in detail embodiments that are in accordance with the present invention, it should be observed that nothing contained in this section is intended to limit the scope of the invention. The scope of the invention is intended to be limited purely by the claims and its equivalence. The following detailed description of the embodiments is provided purely to enhance the understanding of the invention and to assist a person reading the document to work the invention. Accordingly, the elements (or in other words the components) of the device have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of

the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein. The terms "comprises", "comprising", or any other variations thereof, are intended to cover a nonexclusive inclusion, such that a device that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such device. Also, it should be observed that an element proceeded by "comprises... a" does not, without more constraints, preclude the existence of additional identical elements in the device that comprises the element.
The present invention is described with reference to the figures and specific embodiments; this description is not meant to be construed in a limiting sense. Various alternate embodiments of the invention, will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that such alternative embodiments form part of the present invention.
Accordingly, the aircraft arrester of the present invention comprising a barrier having a multiple element net (MEN) assembly placed across a runway. The barrier is movable from a folded position to an erected position. The folded position is when the barrier is in a direction parallel or approximately parallel to the runway so as not to obstruct the path of the aircraft. The erected position is a position is when the barrier is in perpendicular or approximately perpendicular to the direction of the runway so as to obstruct or intercept the path of the aircraft. Obstructing the path of the aircraft means so that the multiple element net (MEN) assembly envelop the aircraft.
Figure 1 shows an aircraft arrester according to an embodiment of the present invention. As shown in figure 1 the aircraft arrester of the present invention comprises an engagement system (1) or a barrier to envelop to envelop the aircraft during its arrestment. The engagement system or a barrier comprises a multiple element net (MEN) assembly, which, when suspended across the runway, forms a complete envelope of protection for an aircraft to be engaged. Any multiple element net (MEN) assembly can be used which is suitable to envelop the aircraft. To prevent the multiple element net (MEN) assembly from drifting due to wind pressure, the bottom straps of the multiple element net (MEN) assembly are anchored to the runway with the help of net anchors fitted over the entire width of the runway. As shown in figure 1 the net anchors (2) are used to anchor horizontal strap provided at the

bottom of the net with the ground. This arrangement prevents the multiple element net (MEN) assembly to fly away due to the wind pressure or aircraft exhaust.
The aircraft arrested of the present invention comprises a means for positioning the barrier according to an embodiment of the present invention. The means for positioning the barrier comprises a pair of stanchions placed across the runway. In other words, the stanchions are placed on each side of the runway. According to an embodiment of the present invention, the stanchions are movable from a folded position to an erected position. In the folded position, the stanchions fall in a direction parallel or approximately parallel to the direction of the runway. In the erected position, the stanchions are perpendicular or almost perpendicular to the direction of the runway. According to an embodiment of the present invention, the stanchions are movable in a vertical plane so that in the erected position the stanchions are vertical. As can be clearly understood, the folded and erected position of the barrier is same as the folded and erected position of the stanchions.
The multiple element net (MEN) assembly is detachably engaged with the stanchions. Any suitable means can be used for detachably engaging the multiple element net (MEN) assembly with the stanchions. According to an embodiment of the present invention, the multiple element net (MEN) assembly attached with a stanchions by means of shear-off coupling.
As shown in figure 1, the means for positioning the barrier can be an engagement support system (3) which comprises a pair of stanchions (4). The engagement system support (3) is also provided with a means to connect the engagement system (1) or barrier to the stanchions and to release the engagement system when an aircraft is arrested or comes in contact with the multiple element net (MEN) assembly.
According to an embodiment of the present invention the engagement support system comprises but not limited to five components, viz., suspension cable, shear off coupling, lifting and pulling machine, restraining cable assembly and suspension cable anchor.
As shown in figure 1 the stanchions (4) are is mounted on a metal frame, which in turn is anchored to a concrete foundation on both sides of the runway.

According to an embodiment of the present invention the multiple element net (MEN) assembly (1) is connected with an end of a tape (5) by means of at least one connection link the other end of the tape is wound on a tape drum. Two connection links can also be provided on each side of the runway. As shown in figure 1, a tape connector (6) can be a connection link between the tape or a purchase tape (5) and the multiple element net (MEN) assembly (1). The tape connector (6) comprises a 'C shaped weldment link and a shaft.
The tape drum is connected with an energy absorber unit according to an embodiment of the present invention. The energy absorber unit arranged to absorb the kinetic energy of the aircraft as the tape plays out following the engagement of the aircraft with the multiple element net assembly. As can be clearly understood, in the erected position the tape is wound on the tape drum and the tape plays out after the aircraft comes in contact with the multiple element net assembly.
Figures 1 and 2 illustrate the energy absorber unit (7) according to an embodiment of the present invention. The purchase tape (5) is main energy transmission between the multi element net assembly (1) and the energy absorber unit (7). The tape or purchase can be a woven nylon belt with ultraviolet resistant treatment to increase wear properties and to provide dimensional stability.
As shown in figure 2 the tape drum can be assembled with the energy absorber unit (7). The energy absorber unit (7) gradually absorbs the kinetic energy of the aircraft during the run out distance, after its engagement in the multiple element net assembly. As can be clearly observed, the connection of energy absorber unit (7) with the multiple element net (1) assembly is made by means of purchase tape (5).
According to an embodiment of the present invention the energy absorber unit comprises a hydraulic braking device. Particularly, a rotary or turbine type hydraulic braking device, which comprises comprising rotary and stationary blades and resisting fluid, can be used as energy absorber unit.
Figure 3 shows an exploded view of the energy absorber unit (7). As the multiple element net (MEN) assembly envelop the aircraft, the movement of aircraft causes pulling of purchase tape off the tape drum which causes rotary motion to the energy absorber unit (7). Rotary

motion of the energy absorber unit (7) agitates the resisting fluid which provides drag to stop the aircraft.
In an embodiment of the present invention the tape or purchase tape is guided by two sheave assemblies (8, 9) on each side of the multiple element net assembly (as shown in figure 1). One sheave installed near the energy absorber called absorber sheave (8) assembly and the other installed near runway edge called runway sheave (9) assembly.
The absorber sheave (8) assembly guides the purchase tape on and off the tape drum. During retraction of the purchase tapes after an arrestment of the aircraft, each absorber sheave assembly keeps it free from twisting, maintains it in a vertical position, and guides it onto the tape drum.
The runway sheave (9) assembly minimizes the tape sweep area and enables the tape to pay out in a well-defined direction on the runway. During retrieval of the tape after an engagement, it holds the tape in an upright position and in alignment with the energy absorber tape drum, making tape retraction easier and reducing tape wear.
Figure 4 shows sheave pulley according to an embodiment of the present invention.
In an embodiment of the present invention the nylon tape or purchase tape is housed in a fairlead tube to keep the path of the nylon purchase tape free of all obstructions and to prevent dirt and debris from being carried into the sheaves and tape drum.
As shown in figure 1, in an embodiment of the present invention each of the energy absorber unit (7) is provided with a pressure roller assembly (10) for maintaining the pressure of the tape against the tape drum. The pressure roller assembly (10) is located adjacent to each energy absorber unit (7) and maintains pressure against the purchase tapes (5) as they are being wound on to the tape drums. A tight, even wrap of the purchase tape, in addition to saving space in the tape drum, also helps in minimizing force fluctuations during an aircraft arrestment.

The aircraft arrester of the present invention can also be provided with a tape-retrieval system (11) according to an embodiment of the present invention. Figure 5 shows a tape-retrieval system (11) for rewinding the purchase tape on to the tape drum after an arrestment.
The raising and lowering i.e. moving the stanchions between the folded and erected position can be accomplished by means of an electrically operated winch device.
According to an embodiment of the present invention the aircraft arrester comprises an electrical control system (12) (as shown in figure 1) for controlling the movement of the barrier from the folded position to the erected position and from the erected position to the folded position. The electrical control system can be used to control the electrical operation of raising and lowering the stanchion system and operation of the tape retrieval system. The electrical control system can include but not limited to a motor, a limit switch and an electronic timer.
Figures 6 and 7 illustrate a multistage geared brake motor and a limit switch which can be used in an electrical control system (12).
According to an embodiment of the present invention the limit switch comprises a front limit switch and rear limit switch. The front limit switch is basically responsible for stopping the flow of power to the motor when down position limit of the stanchion is reached. This is a protective function by which the motor is saved from becoming unserviceable. The rear limit switch is basically responsible for stopping the flow of power to the motor when up position limit of the stanchions is reached. This is also a protective function by which the motor is saved from becoming unserviceable.
The electronic timer allows the flow of power supply to the motor for a pre-determined duration after that the supply to the auxiliary contactor is stopped which stops the motor.
The electronic control system (12) is also provided with an override switch in accordance of an embodiment of the present invention. Over ride switch provides a protective function stopping the flow of power to the motor in case of both limit switch and the timer fail to operate. Therefore, over ride switch gives additional protection to the over all system providing robustness.

The sequence of operation of limit switch, electronic timer and over ride switch can be as follows according to an embodiment of the present invention. During Raising (i.e. moving the barrier or stanchions from folded position to the erected position, the rear limit switch and timer are operated almost at the same time and motor gets stopped. If the limit switch and timer simultaneously fail to operate then the over-ride switch actuates and stops the supply to the motor. During Lowering (i.e. moving the barrier or stanchions from erected position to the folded position the front Limit Switch and timer are operated almost at the same time and motor get stopped. In this condition the over ride switch is not used.
The electrical control system (12) can be operated by a radio command system (13) shown in figure 8. The Radio Command System (13) is used to control the electrical operation of raising and lowering the stanchion system by Radio waves. The Radio Command System consists of one master unit (14) and one slave unit (15). Master unit (14) can be kept at Air Traffic Controller (ATC) or at any place as per requirement and slave unit (15) is kept inside a main control panel of electrical control system. A remote control panel can be provided in the Radio Command System (13).
The following paragraph describes method of operating or working of aircraft arrester according to an embodiment of the present invention.
The multiple element net assembly is kept raised with two stanchions. It is connected to stanchion with the help of engagement system support consisting of shear off coupling, wire rope (suspension cable) and attaching hardware. Shear off coupling consist of a shear pin which shears off during engagement to free the net from top. The lower horizontal portion of the multiple element net assembly is anchored to the runway with the help of Net Anchors. The multiple element net assembly is connected to purchase tape with the help of mechanical link called tape connector. Travel of purchase tape is guided by roller assembly called sheave assembly. Purchase tape is wounded over the tape drum of Energy absorber. Energy absorber is a turbine type system consisting of rotary and stationary blades.
The Stanchion system falls parallel to the runway. The Multiple Element Net Assembly is raised with the help of stanchion system on a command received through remote control located in the ATC tower, when emergency arresting of an aircraft is necessitated. As the net envelopes the aircraft, the pull exerted by aircraft to shear the shear pin of hear off coupling,

releasing the net top from the engagement system. Further movement of aircraft causes the pulling of the purchase tape which in turns provides the rotary motion to energy absorber. The Fluid of energy absorber is agitated to provide drag to stop the aircraft.
After the arrestment, the multiple element net assembly is manually disconnected from the purchase tapes. The purchase tapes are rewound on the tape drum with the help the tape retrieval systems. The aircraft arrester is now ready for another arrestment.
As can be clearly observed from the above paragraphs, the present invention provides an aircraft arrester which has number of advantages. Some of the distinguishing features of present invention as compared to the prior art are as follows:
1. Four friction brake type energy absorbers were used in the prior art system whereas two water twister type energy absorber are used in the present invention
2. Only hook type aircraft can be engaged with prior art barriers, whereas non hook type can be engaged with the present invention
3. In the prior art system, tape spools are configured for one time use, tape spool were to be replaced for next engagement, whereas the aircraft arrester of the present invention is reusable.
4. In the present invention rewinding technology of purchase tape after arrestment of aircraft is based on an electric motor supplied with the system. While in the prior art system for rewinding of purchase tape hydraulic energy, which is stored during arrestment of aircraft, is used.
Some more advantages and features of the present invention are as follows:
1. According to an embodiment of the present invention an illuminating device can be provided as shown in figure 9. The illuminating device is helpful to identify the barrier from a distance so that pilot can locate the centre of the mechanical decelerator during night operation.
2. In another embodiment of the present invention strong mechanical component with better shock absorbing capabilities are introduced so that during lowering position the stanchion should have jerk free descent. As shown in figure 10, a hydro-pneumatic shock absorber can be provided with the stanchions.

3. The larger diameter and better material of sheave pulley enables the longer life of suspension cable with minimum wear and abrasion.
4. The constructions of wire ropes are selected in such a way that abrasion on the wire rope will be minimal which helps more service life. As shown in figure 11 a particular construction of wire rope can selected according to an embodiment of the present invention.
5. The multi stage gear mechanism of electrical motor provides low power consumption and a longer life.
6. A state of the art limit switches which have under water operational capabilities means reliable operation in severe environmental conditions.
7. The components of the energy absorber are fabricated/ manufactured from a material, which can sustain instantaneous resisting torque. The fluid compositions are selected in such a way it will enhance the brake capabilities.
8. A retrieve system will provide enough power to rewind the flexible tape onto the tape drum of the energy absorber with minimum power consumption.
9. According to an embodiment of the present invention the aircraft arrester of the present invention can be designed form 6 to 20.4 Ton class of aircraft.
10. In another embodiment of the present invention the aircraft arrester of the present invention can be designed form 40 Ton class of aircraft.
The foregoing detailed description has described only a few of the many possible implementations of the present invention. Thus, the detailed description is given only by way of illustration and nothing contained in this section should be construed to limit the scope of the invention.

We Claim:
1. An aircraft arrester comprising:
a barrier comprising a multiple element net (MEN) assembly placed across a runway; said
barrier is movable from a folded position, which is in direction generally parallel to a runway
to an erected position, which is intercept path of the aircraft to envelop the aircraft;
a means for positioning the barrier comprising a pair of stanchions placed across the runway;
the stanchions are movable from a folded position, which is generally parallel to a runway to
an erected position, which is generally perpendicular to the runway;
a means for detachably engaging the MEN assembly with the stanchions;
at least one connection link connecting one end of a tape with the MEN assembly; other end
of the tape is wound on a tape drum;
an electrical control system comprising a motor, a limit switch unit and an electronic timer to
control the movement of the barrier from the foldable position to the erected position and to
control the movement of the barrier from erected position to the folded position;
an energy absorber unit connected with the tape drum for absorbing the kinetic energy of the
aircraft as the tape plays out following engagement of the aircraft with the MEN assembly.
2. The aircraft arrester as claimed in claim 1, wherein the limit switch unit comprises a rear limit switch configured to co-operate with the electronic timer to control flow of power to the motor during movement of the barrier from folded position to the erected position.
3. The aircraft arrester as claimed in claim 1, wherein the limit switch unit comprises a front limit switch configured to co-operate with the electronic timer to control flow of power to the motor during movement of the barrier from erected position to the folded position.
4. The aircraft arrester as claimed in claim 2, wherein electrical control system comprises an override switch configured to stop flow of power to the motor upon failure of rear limit switch and timer.
5. The aircraft arrester as claimed in any one of the preceding claims 1 to 4, wherein the MEN assembly is provided with bottom strap and anchoring means to anchor the MEN assembly on the runway to preventing the MEN assembly from drifting due to wind pressure/ aircraft exhaust.

6. The aircraft arrester as claimed in any one of the preceding claims 1 to 5, wherein the means for detachably engaging the MEN assembly with the stanchions comprises a suspension cable, a shear-off coupling, lifting-pulling machine, restraining cable assembly and suspension cable anchor.
7. The aircraft arrester as claimed in any one of the preceding claims 1 to 6, wherein the means for positioning the barrier comprises electrically operated winch device for moving the stanchion from the folded position to the erected position and from erected position to the folded position.
8. The aircraft arrester as claimed in any one of the preceding claims 1 to 7, wherein the connection link comprises a 'C shaped weldment and a shaft.
9. The aircraft arrester as claimed in any one of the preceding claims 1 to 8, wherein the tape is a woven nylon belt with ultraviolet resistant treatment.
10. The aircraft arrester as claimed in any one of the preceding claims 1 to 9, wherein the energy absorber unit comprises a hydraulic braking device coupled to the tape drum.
11. The aircraft arrester as claimed in any one of the preceding claims 1 to 10, wherein the energy absorber unit is provided with pressure roller assembly for maintaining the pressure of the tape against the tape drum.
12. The aircraft arrester as claimed in any one of the preceding claims 1 to 11, wherein the tape is guided by (a) an absorber sheave assembly, which guides the tape on and off the tape drum; and (b) a runway sheave assembly, which minimizes the tape sweep area and enables the tape to play out in a well defined direction.
13. The aircraft arrester as claimed in any one of the preceding claim 1 to 12, wherein electrical control system comprises a tape retrieval system.
14. The aircraft arrester as claimed in any one of the preceding claims 1 to 13, wherein the electrical control system comprises a main control panel located at the runway site a remote

control panel of a radio command system for controlling the electrical operation of moving the barrier from the folded position to the erected position and from the erected position to the folded position.
15. The aircraft arrester as claimed in any one of the preceding claims 1 to 14, wherein the radio command system comprises a slave unit, located in the main control panel of the electrical control system and master unit located at a location remote from the main control panel.
16. An aircraft arrester substantially as herein described with reference to the accompanying drawings.