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This paper aims to present a theoretical method for analyzing the stability and control of a hingeless helicopter in the presence of windshear.

In this paper, the stability and control of a hingeless helicopter in the presence of windshear are investigated. First, the rotary wing dynamic model considered is the one of flap‐pitch (including the elastic deformation of the control system)‐torsion coupling. The induced velocity nonuniform distribution derived from vortex theory is taken into account. Then, as for atmospheric turbulence, the linear windshear model is used for modeling the variation of wind field. Finally, according to the calculated results of the stability characteristic roots and the control response of the helicopter, the helicopter performance in wind shear field is analyzed, and some conclusions are obtained.

Some useful conclusions are obtained through sample analysis.

Although the analyses for stability and control of a hingeless helicopter in the presence of windshear could be obtained using the current method, the model of complex wind field will still be expected in future studies.

A very useful method for analyzing helicopter stability and control.

The proposed method is valid and available for the analysis of helicopter flight dynamics.

Control laws that are based on the nonlinear inverse dynamics (NID) of the aircraft offer the potential for providing improved levels of performance over conventional flight control designs. The NID and its application in the flight control during windshear penetration are introduced here. With the employment of a real engineering windshear model and NID, a low‐altitude windshear penetration flight control law is designed. The simulative calculation results indicated that the NID control logic works effectively in the trajectory control of the aircraft during the penetration of windshear.

This study presents a preliminary evaluation of the application of Thrust Vectoring (TV) technology for improving windshear recovery of civil aircraft in microburst windshear encounters. A numerical trajectory optimization technique based on the method of multiple shooting is applied to achieve a microburst escape with minimal loss of altitude for a Boeing 727 type aircraft. Although the application of TV does result in a slight improvement in recovery altitude, there is also a price to be paid in the sense that TV utilization significantly hampers the ability to gain specific energy during recovery. Maintaining an energy buffer during a microburst encounter is highly desirable to achieve robustness with respect to uncertainness in windshear size and strength. TV aided windshear recovery has also been compared with an alternative approach to improve the windshear survivability capability, namely, the application of lateral maneuvering. The comparison shows that lateral maneuvering is not only a far more effective means to improve the recovery altitude, it also vastly improves energy preservation. In a view of the results established in this study, we feel that TV does not hold out great promise as a useful means to truly improve windshear recovery.

THE FAA has certified the Honeywell/McDonnell Douglas Windshear Detection Alert and Guidance System on the McDonnell Douglas MD‐80 series aircraft, the two companies announced.

JUST as no new commercial aircraft is allowed to carry fare‐paying passenger on its first flight, no significant change to air traffic control (ATC) services is approved for operation until it has undergone a proper programme of development and test. The Air Traffic Control Evaluation Unit (ATCEU) is located at Bournemouth International Airport and is part of the National Air Traffic Services (NATS). Ever since 1947 it has been actively engaged in helping to ensure that, when new ATC equipments, procedures and systems are introduced to operational service, they will meet the rigorous requirements of a safety‐conscious aviation industry.

The family of Rolls‐Royce RB211 large fan engines now extends to power two‐, three‐, and four‐engined airliners. To the end of July, more than 430 orders and options had been announced for RB211 powered aircraft, involving total sales of over 1,450 engines.

Major technical advances were featured at the Show, particularly those developments that will be coming into service in the very near future. An outstanding demonstration was given by the Airbus Industrie A 300B2 Fly‐By‐Wire (FBW) whose autopilot simulates the control laws of the A 320. The pilot flies the aircraft through the FBW autopilot using the sidestick controllers as in the A 320, which is due to make its first flight in March, 1987. A convincing display by the A 300 FBW began with a slow fly‐past in landing configuration with gear and flaps down at a speed of about 100 knots. At mid‐runway position, the crew simulate a windshear encounter and the captain pulls back on the stick as might happen in such a situation. In a standard ‘conventional’ aircraft, this would lead to a stall with potentially disastrous consequences, but with FBW the pitch angle increases to the point where the wing reaches its maximum lift position and stays there. The ‘alpha‐floor’ protection incorporated in the aircraft then automatically increased engine power and the combination of maximum lift and power results in a climb‐out at 3,000ft/min. In another manoeuvre, the aircraft is positioned at an angle of attack of 15.5° in order to stabilise speed at 95–100 knots and only just below the limit of 17° — 18°. Also demonstrated was a stall turn with the nose up to maximum angle of attack and bank angle of 30° which stops there despite the fully‐deflected stick position. The engine power in this manoeuvre is controlled manually.

Rolls‐Royce has received certification for the RB211‐535 to be used for test flights on Russia's Tupolev Tu‐204 airliner.

Turkish Airlines (THY) has chosen Honeywell to supply Traffic Alert and Collision Avoidance Systems (TCAS) for its Airbus A310s and A340s and Global Positioning/Air Data Inertial Reference Systems (GP/ADIRS) for its A340s.