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This paper discusses the side stick and fly by wire elements of the Airbus Industrie A320. After discussion of the cockpit and the effect on it of the side sticks, the arrangements of the side sticks themselves is discussed, travel, forces and electronic coupling. The control laws form the body of the paper with some emphasis on the new things that become possible with fly by wire that Airbus Industrie has vested in A320. Pitch roll and yaw control are discussed in detail and so to are the protection systems that will contain the flight path within safe limits. Some illustrations of the functioning of the protection system in flight on a test A300 equiped with the A320 control laws will be presented.

Future aircraft requirements dictate the need to integrate all aspects of an engine starting system early in the program. In the past, an engine starter was sized, designed, and selected with minimal consideration of its application to the total aircraft system. Then came expanded aircraft requirements, such as extended motoring, clearing engine stalls, making leak checks, and integrating the starter system with secondary power systems and/or start self-sufficiency. The result: costly extensive revisions of the original design. To avoid this in the future, efforts must be made to consider as many as possible of the above factors early in the initial design phase. This paper presents the many aspects of system design and provides technical approaches which will satisfy specific requirements in a program's preliminary design phases. Pneumatic systems are typical of the various types of starter systems being addressed.

In addition to designing fighter engines for stall-free idle to maximum power operation and stall recoverability, it is important to give proper emphasis to sub-idle operation for successful starting. This permits the pilot to confidently bring the engine on-line following an inadvertent flameout caused by either the airplane departing the flight envelope or by a fuel interrupt due to a malfunction. Thus reliable and fast airstart capability enhances flight safety especially of single engine airplanes. Flight testing, therefore, is substantially devoted to airstart evaluation. The paper first explains the influence of engine design features on airstarting, particularly the advantages of the low bypass ratio cycle F100-PW-229 (PW229) engine, which is an increased thrust derivative (IPE) of the highly successful F100-PW-220 engine. Enhancing airstarting capability of the PW229 using variable geometry features and digital control flexibility is discussed.

The Diagnostics Tested Facility (DTF) at NASA's John C. Stennis Space Center (SSC) in Mississippi was designed to provide a testbed for development of rocket engine exhaust plume diagnostics instrumentation. A 1200-lb thrust liquid oxygen (LOX)/gaseous hydrogen (GH2) thruster is used as the plume source for experimentation and instrument development. Theoretical comparative studies have been performed with aero-thermodynamic codes to ensure that the DTF thruster (DTFT) has been optimized to produce a plume with pressure and temperature conditions as much like the plume of the Space Shuttle Main Engine (SSME) as possible. Operation of the DTFT is controlled by an icon-driven software program using a series of soft switches. Data acquisition is performed using the same software program. A number of plume diagnostics experiments have utilized the unique capabilities of the DTF.

There is a need for a space launch system that can provide ready, reliable, unencumbered access to space. The need exists for a highly reliable launch system that can operate from numerous available sites, that can provide all azimuth launch capability, that is fully reusable, and that can carry significant payloads into low earth orbit. A vehicle concept was developed to demonstrate the ability of near term aeromechanics and propulsion technology to support such a system. The vehicle was composed of two stages. The system takes off horizontally and both stages return to a horizontal landing. Turbojet, ramjet, and rocket propulsion is used. The sensitivity of the system to thrust, drag, weight, and staging Mach number was examined. The two stage system is able to accommodate a range of performance variations yet still retain significant mission potential.

Using LH2 heat sink capacity for air precooling in turbojets allows to increase specific impulse and in many cases to reduce specific mass (mass-to-sea level thrust ratio). A number of precooled turbojet schemes are considered. Classification of turbojet according to the cooled air amount and depth of cooling is proposed. ATR with extended precooling (Tout=100K) is examined in more detail. For propulsion systems including different types of engines, running simultaneously the concept of LH2 heat sink capacity concentration for turbojet air precooling is proposed.

A main objective of the STOL and Maneuver Technology Demonstrator, (S/MTD) Program was to evaluate the operability and performance of its unique engine/nozzle configuration which can deliver thrust in three different modes; conventional, vectored and through variable vanes which give the option of going from forward to reverse thrust. The two-dimensional nozzle and the modified engine were extensively tested during sea level and altitude testing to satisfy all flight clearance requirements. This paper concentrates on the flight test results of the various modes of vectoring and reversing ending with a compilation of the actual usage of the propulsive controls that could be used by designers of similar advanced propulsion systems.

Aerodynamic effects induced from vectoring an exhaust jet are investigated using a well established thin-layer Reynolds averaged Navier-Stokes code. This multiple block code has been modified to allow for the specification of jet properties at a block face. The applicability of the resulting code for thrust vectoring applications is verified by comparing numerically and experimentally determined pressure coefficient distributions for a jet-wing afterbody configuration with a thrust-vectoring 2-D nozzle. Induced effects on the body and nearby wing from thrust vectoring are graphically illustrated.

This paper presents an overview on an Air Force initiative aimed at increasing the performance and reliability of aircraft batteries. A major thrust of the initiative is the elimination of flight line battery maintenance shops. Cost savings, increased mission capability and battle readiness are the pay-offs that will be realized from this effort. Current maintenance requirements for vented nickel-cadmium (Ni-Cd) batteries used in most U.S. military aircraft are unacceptable. This paper addresses other available technology options, decisions made to date and benefits that will result from this effort to increase the performance and reliability of aircraft batteries.

An elementary analysis has been made of generic wing-body configurations with variable volume allotment in wing and body, for constant total useful volume, including the all-wing configuration. These aircraft were compared on the basis of the Lift-to-Drag (L/D) ratio, for specified flight conditions. In addition the parameter ML/D for constant corrected thrust has been optimized, resulting in certain combinations of altitude and speed for maximum specific range (if corrected TSFC = constant). Finally, the effect of volume allotment on L/D for given engine size was studied. It has been found that in many cases optimum volume allotments indicate that wing-body combinations are to be favored. Only in the case of relatively low Mach numbers and high-altitude flight the flying wing outperforms conventional aircraft, but it will generally require larger engines.

This paper deals with a thrust generation method which can be applied to nuclear as well as chemical propulsion systems. It takes into consideration both incompressible and compress-ible flow cases, however both of these cases are based on one dimensional flow within an ideal rocket framework. In the case of constant area duct steady state flow the obtained Induced Thrust (IT) formula is: where p1 and p2 are opposing pressure fields and u* is a function of u2, p2 and u1 (u1 and u2 being opposing gas efflux velocities). For the compressible and incompressible flow fields, IT formulas are obtained but they are not as reliable. One feasible application for this launch-propulsion method is the Joined-Ship model. In this model the combustion chamber pressure within one space vehicle acts as the back pressure of the joined space vehicle and vice-versa.

The Comet Rendezvous Asteroid Flyby (CRAF) mission involves seven years of flight from 0.6 to 4.57 Astronomical Units (AU), followed by about 915 days of maneuvering around a comet. Ground testing will characterize the very critical attitude control system thrusters' fuel consumption and performance for all anticipated fuel temperatures over thruster life. The ground test program characterization will support flight condition monitoring. A commercial software application hosted on a commercial microcomputer will control ground test operations and data acquisition using a newly designed thrust stand. The data acquisition and control system uses a graphics-based language and features a visual interface to integrate data acquisition and control.

After seven years of test flying and more than fifteen years of commercial operations Concorde remains unrivalled and unique among civil transport aircraft. Many problems, technical, political and financial have been overcome and the aircraft, flagship of both Air France and British Airways, is now proven, safe and reliable. The aircraft's unmistakable low aspect ratio delta wing, optimized for supersonic cruise, brings with it the penalty of high drag at low speed; a factor impressed on flight crews during initial conversion to type. Concorde's large flight envelope is severely restricted by the need to balance the movement of the aerodynamic centre of pressure by a shift of aircraft Centre of Gravity. The dual-compressor axial flow Rolls-Royce Olympus engines, augmented by afterburning for take-off and transonic acceleration, provide the high jet velocity and high thrust needed for Mach 2 flight.

To the casual airline passenger the appearance of the Boeing 747-400 jetliner is identical to that of the older model 747-300 with the exception of the winglets. However, modifications and improvements include modern digital avionics, a “glass” cockpit and more powerful rudder control surfaces to cope with the growth in engine thrust. The upper rudder is positioned by three parallel actuators and powered by two independent hydraulic systems. Flow control is provided by a triple tandem servovalve which maintains actuator force fight below allowable limits and synchronizes hydraulic flow to the three actuators. This paper describes the requirements, design, development, analysis and iron bird testing of some of the unique features of the upper rudder hydraulic control system.

A nonintrusive high-angle-of-attack flush airdata sensing system was installed and flight tested on the F-18 High Alpha Research Vehicle at the NASA Dryden Flight Research Facility. This system consists of a matrix of 25 pressure orifices arranged in concentric circles on the nose of the vehicle to determine angles of attack and sideslip, Mach number, and pressure altitude. During the course of the flight tests, it was determined that satisfactory results could be achieved using a subset of just nine ports. The high-angle-of-attack flush airdata sensing system was calibrated and demonstrated using reference airdata generated by way of minimum variance estimation techniques which blended airdata measurements from two wingtip airdata booms with inertial velocities, aircraft angular rates and attitudes, precision radar tracking, and meteorological analyses. Calibration results are presented.

The results of computational investigations carried out to clarify the possibilities of hydrogen scramjet thrust uprating in hypersonic flight (M >8) by adding to the fuel substances with higher density are presented. Thrust, specific impulse and density impulse are calculated while adding nitrogen, oxygen, water or inert liquated gases. Fuel is injected tangentially to air flow into combustion chamber with high velocity through gas generator nozzles. For scramjet boosting in hypersonic flight it is suggested to add oxygen to stoichiometric part of hydrogen instead of excessive part of hydrogen.

Air Force Research Laboratory (AFRL) is pursuing development of advanced, distributed, intelligent, adaptive engine controls and engine health monitoring systems. The goals this pursuit are enhancing engine performance, safety, affordability, operability, and reliability while reducing obsolescence risk. The development of smart, high-bandwidth, high-temperature-operable, wide-range, pressure/temperature multi-sensors, which addresses these goals, is discussed. The resulting sensors and packaging can be manufactured at low cost and operate in corrosive environments, while measuring temperatures up to 2,552 °F (1,400 °C) with simultaneous pressure measurements up to 1,000 psi (68 atm). Such a sensor suite provides unprecedented monitoring of propulsion, energy generation, and industrial systems. The multi-sensor approach reduces control system weight and wiring complexity, design time, and cost, while increasing accuracy and fault tolerance.

A discussion on the development of a Telescoping, Vaned, Exhaust Nozzle (TEVEN) is presented. This nozzle was challenged to meet the thrust vectoring requirements of an Advanced Short Takeoff and Vertical Landing (ASTOVL) aircraft. The nozzle underwent a development process from concepts to detail design using computational flow analyses and from subscale performance verification tests to full-scale hardware design. The LiftFan™ nozzle is capable of providing a pitch vector range of about 80 degrees from up to 20 degrees forward to 60 degrees aft. In addition, a set of post exit yaw doors provide ± 10 degrees yaw while maintaining a relatively high performance at all operating conditions. Further, the nozzle is axially compact, to be stowable in very short length (L/D < 0.3), while efficiently converging the upstream nozzle flow from an annular cross section to a “D” shape at the nozzle exit.

An axisymmetric slender body comprising an ogive-cylinder (or ellipsoid -cylinder) shell enclosing an engine is analysed at various incidences to an incompressible uniform free stream for several jet flow rates on the basis of integral equation method.The pressure distributions, normal force, pitching moment, drag and thrust are calculated. The results with and without the effect of the exhaust jet flow are presented to show the influences of the jet mass flow rates on the aerodynamic properties.

Integration of propulsion and flight-control systems will provide significant performance improvements for supersonic transport airplanes. Increased engine thrust and reduced fuel consumption can be obtained by controlling engine stall margin as a function of flight and engine operating conditions. Improved inlet pressure recovery and decreased inlet drag can result from inlet control system integration. Using propulsion system forces and moments to augment the flight-control system and airplane stability can reduce the flight-control surface and tail size, weight, and drag. Special control modes may also be desirable for minimizing community noise and for emergency procedures. The overall impact of integrated controls on the takeoff gross weight for a generic high speed civil transport is presented.