Aircraft carriers and methods of operation thereof

Details Aircraft carriers and methods of operation thereof Aircraft carriers and methods of operation thereof

1999-12-10

2001-08-28

Morano, S. Joseph (Department: 3617)

Ships

Mother ship, floating landing platform, and harbor

Aircraft

C114S259000, C114S272000, C244S11400R

Reexamination Certificate

active

06279500

ABSTRACT:

This invention relates to aircraft carriers and associated devices and methods of operation thereof to assist or enhance landing of aircraft on an aircraft carrier.
Recent studies of the possible use of modern fighter aircraft such as the Eurofighter in a naval role have suggested that the landing speed of the aircraft might be determined by the pilot-view-limited angle of attack (that is the angle of attack of the aircraft should be low enough for the pilot to have an adequate view of the flight deck when landing) rather than a defined stall margin. This is because aircraft such as the Eurofighter have a relatively low lift slope and the stalling angle is relatively high. Accordingly, in one aspect, this invention is concerned with providing a solution to the problem of allowing the pilot to land the aircraft at an angle of attack which gives him sufficient view of the flight deck and any surrounding visual cues from the cockpit whilst maintaining or reducing the touch-down vertical and horizontal velocities to acceptable levels.
With this in mind, we have analysed the airflow downstream of a ship (the airwake) in a conventional aircraft carrier and designed a modified form of aircraft carrier to provide a positive or increased upwash angle of the airwake behind the ship, so that the flight attitude of the aircraft may be lowered and hence the pilot view enhanced whilst maintaining an effective angle of attack greater than the flight attitude. Our initial studies suggest that the provision of an increased upwash angle should reduce the landing speed and provide some enhanced ground effect and hence a more gentle landing.
The natural airwake of a ship due its forward speed and natural wind has a small downwash component (burble) in the flow immediately behind the stern. This results because of the natural filling of the base region of separated airflow behind the ship from all possible areas, namely from the two sides and from above (i.e. the flight deck). Accordingly, in the embodiments described below, the flow from the flight deck is deflected upwards so that the base region of separated airflow behind the ship is filled only from the sides. The flow directed at an upwardly inclined angle from the end of the flight deck may then continue to flow at an upwardly inclined angle and provide an incremental upwash effect which persists for some distance behind the ship.
British Patent Specification No. 1,052,359 discloses a water-borne take off and landing craft which is intended to be propelled by jet engines through the water at a speed equivalent to the landing speed of an aircraft intending to land on the craft. The engines are disposed at the rear of the ship and spaced to either side of the approach path of the aircraft, and are directed horizontally. There is no suggestion of providing an increased upwash in the approach path of the craft to allow the usual flight attitude of the aircraft to be lowered.
British Patent Specification No. 1,036,015 discloses an arrangement for clearing sea mist or fog from the approach path behind an aircraft carrier. Hot efflux is discharged from the front of the craft from a turbojet or the like to lay a trail of hot air along a glide path behind the craft, to clear sea mist or fog. There is no suggestion in this document of an arrangement in which a flow deflection means is disposed in the aft end region of the flight deck to provide an increased upwash, nor of an arrangement in which the increased upwash is used to allow the usual flight attitude of the aircraft to be lowered.
British Patent Specification No. 542,901 discloses an arrangement designed to obstruct a landing strip, which projects upwardly. There is no suggestion of the use of such a device to provide an increased upwash behind an aircraft carrier.
British Patent Specification No. 343,763 discloses an arrangement in which an artificial antagonistic wind is generated by means of a blower or generator disposed at the front of the aircraft, some distance off the deck. The blowers or generators emit their efflux generally rearwardly.
Accordingly, in one aspect, this invention provides an aircraft carrier including a flight deck on which aircraft may land, said flight deck having a forward end and an aft end, said aircraft carrier having disposed in the aft region of said flight deck airflow deflection means for imparting to airflow passing along said flight deck in the general direction from said forward end to said aft end an upwardly inclined component of velocity, to provide or increase an upwash in the airwake in the aircraft approach path behind the aircraft carrier.
The airflow deflection means may be disposed at a number of different positions but it is preferred for this to be disposed at an aft end region of the flight deck to increase the extent of the airwake over which the upwash effect is effective.
The airflow deflection means may take many forms and conveniently comprises a generally upwardly inclined deflection surface which is disposed generally transversely to the landing direction, and extending substantially continuously thereacross.
The airflow deflection means may comprise a deflection surface of substantially uniform height across at least a substantial transverse extent of the flight deck. Alternatively, the airflow deflection means may comprise a deflection surface with a central portion of substantially uniform height. In one arrangement, the airflow deflection means may comprise a central gap where the deflection surface has an effective zero height. Alternatively, the central portion may be higher than the two side portions which diminish in height towards the sides of the carrier.
Although the deflection surface might be a permanent fixture, for example a permanent curved or projecting surface, in one aspect the deflection surface may be moveable between a deployed operative position and a stowed inoperative position.
For safety, the deflection surface should withstand the wind force encountered in normal operating conditions but be adapted to move to a collapsed condition or yield or rupture on accidental impact therewith by an aircraft or a part thereof.
In one embodiment, the deflection surface means comprises a flap element.
In another embodiment, said airflow deflection means comprises airflow generating means for generating a generally upward flow of air. By “upwards” we mean lying at an angle of within ±45° to the vertical, although in many instances the flow of air may be generally vertical i.e. within ±10° to the vertical.
In this embodiment, the airflow generating means may typically comprise a source of pressurised air such as a blower or compressor, and a slot means through which in use said pressurised air exhausts, thereby to generate said upward flow.
In another aspect, this invention provides a method of operating an aircraft carrier which has a flight deck on which aircraft can land, said flight deck having a forward end and an aft end, which method comprises causing said aircraft carrier to travel in a direction to cause an airflow to pass over said flight deck with a substantial component generally in the direction from said forward end to said rearward end, and imparting to the flow over said flight deck a generally upwardly inclined component of velocity.
Whilst the invention has been described above, it extends to any inventive combination of the features set out above or in the following description.


REFERENCES:
patent: 1709058 (1929-04-01), Brunner
patent: 3196822 (1965-07-01), Bertin et al.
patent: 3362368 (1968-01-01), Ringleb
patent: 4700912 (1987-10-01), Corbett
patent: 5127609 (1992-07-01), Lynn
patent: 5429324 (1995-07-01), Lynn
patent: 0 579 508 A1 (1994-01-01), None
patent: 2677326 (1992-12-01), None
patent: 343763 (1931-02-01), None
patent: 542907 (1942-02-01), None
patent: 1036015 (1966-07-01), None
patent: 1052359 (1966-12-01), None

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