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This paper describes the engine design details of the Pratt & Whitney JT15D-1 engine as related to noise generation. Design principles and factors contributing to the very low-noise levels on the Cessna Citation aircraft are illustrated. Noise testing experiences and data from static tests on the United Aircraft of Canada Ltd. (UACL) flight test aircraft and from both static and flight tests on the Citation aircraft are discussed. Lessons learned from these tests and some future probabilities are outlined.

To a large degree all of us at one time or another have envisioned our “Over the Rainbow” version of a future should be. System engineers envision perfect harmony between vehicle aerodynamics and avionics integration. The program manager dreams of schedules and funding well within the projected budget. Then reality; budget constraints, backward compatibility, technology availability, schedule problems, and etc. This paper is intended to recognize the “dreamer” and at the same time offer a means of reconciliation to the real world. We will address advanced avionics architectures and a transitionary means to attain our goals and objectives. An “Avionics System Index” will be presented which defines and specifies a means of describing and partitioned avionics configuration.

When looking into using PCMCIA PC Cards in the avionics market, three areas must be researched. The first is what are the applications and benefits of using the PC Cards while in flight, followed by the applications and benefits on the ground, and thirdly on how to make a PC Card that would stand up to the rugged avionics environment. PCMCIA PC Cards can be used in all aspects of flight. Three possible applications on the ground are; paperless documentation, modifications, flightline changes. Once airborne, PC Cards can be removed and a different functionality card can be inserted. One PC card socket can be used for many different functions during one flight. Some of the possible applications for PC Cards inflight are; flight plan changes, backup Line Replaceable Units (LRUs), and solid state data collection.

eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is a powerful X-ray telescope under development by the Max-Planck-Institut für extraterrestrische Physik (MPE) in Garching, Germany. eROSITA is the core instrument on the Russian SRG1 mission which is planned for launch in 2011. It comprises seven nested Wolter-I grazing incidence telescopes, each equipped with its own CCD camera. The mirror modules have to be maintained at 20°C while the cameras are operated at -80°C. Both, mirrors and CCDs have to be kept within tight limits. The CCD cooling system consists of passive thermal control components only: two radiators, variable conductance heat pipes (VCHP) and two special thermal storage units. The orbit scenario imposes severe challenges on the thermal control system and also on the attitude control system.

This specification covers a zinc alloy in the form of die castings.

(From Standards Proposal No. 2358, formulated under the cognizance of the EIA Quality and Reliability Engineering (QRE) Committee.)

Conventional attribute sampling plans based upon nonzero acceptance numbers are no longer desirable. In addition, emphasis is now placed on the quality level that is received by the customer. This relates directly to the Lot Tolerance Percent Defective (LTPD) value or the Limiting Quality Protection of MIL-STD-105. Measuring quality levels in percent nonconforming, although not incorrect, has been replaced with quality levels measured in parts per million (PPM). As a result, this standard addresses the need for sampling plans that can augment MIL-STD-105, are based upon a zero acceptance number, and address quality (nonconformance) levels in the parts per million range. This document does not address minor nonconformances, which are defined as nonconformances that are not likely to reduce materially the usability of the unit of product for its intended purpose.

This specification covers a zinc alloy in the form of die castings.

The new approach used for the YJ101 development program has produced achievements which are applicable to future engine programs. A description is presented of the YJ101 engine as well as the unique development program leading to flight qualification. Two specific achievements are reviewed; first, the inlet-engine compatibility, and second, engine life evaluation. The inlet compatibility program established specific steps to be followed to achieve stall-free engine operation. The objectives of each step are reviewed. Realistic engine development testing is recognized as a key requirement for the engine industry. Correlation of factory testing with service usage is important to the development of a methodology for engine testing. An analysis of the actual YF-17 engine operation is made and compared to factory development testing. Further development of these concepts is required.

The YF-23A Advanced Tactical prototype Fighter was a revolutionary statically unstable, twin engine aircraft that cruised at supersonic speeds without afterburner and was designed to out maneuver opponents at subsonic and supersonic speeds. Combining these capabilities into a chosen aircraft configuration demanded a flight control hydraulic system of unprecedented power and performance. Increased system reliability, and reduced maintenance also presented a challenging system design. The YF-23A's unique flight and maneuvering envelope required high surface rates and large actuator excursions at low flight speeds, as well as power to generate increased hinge moments at supersonic speeds. To achieve these specifications, Northrop developed a hydraulic system that utilized flow conservation and prioritization techniques. The hydraulic system configuration was maintained by using hydrologic, as well as electronic control.

The status of the YC-14 program is described in this paper in two respects: (1) progress of the design, development and manufacture of the flight articles; and (2) progress that components of the YC-14 make relative to current goals of the aircraft industry. Technology areas where the YC-14 has made distinct contributions are described and indications are given as to the relative contribution and the remaining potential for development. Such areas include low-speed aerodynamic development, fuel conservative design, flight controls technology, and design-to-cost techniques. In all cases, criteria for incorporation were based not only on technological merit but also on the requirement of minimum life-cycle cost. These elements have been incorporated in an operationally capable aircraft that is concluding its manufacturing phase on schedule and is about to begin its flight test program.

The Army's new Advanced Attack Helicopter - the YAH-64 - achieves high performance with low cost and excellent maintainability. These desirable characteristics result from the Design Simplicity which has been inherent in the design approach since conception in 1972 and throughout the Phase 1 and Phase 2 development and flight test program. This inherent simplicity is the direct result of several fundamental decisions regarding basic configuration, plus intensive discipline at all levels of the design.

This paper presents lessons learned from flight testing of the YA-10B Single Seat Night Attack (SSNA) testbed. The generic night attack avionics suite in the YA-10B was used to provide a workload baseline for use in future night attack programs. Pilot rating scales and physiological data were used to construct the workload data base.

Five XC-142 aircraft have been manufactured to provide operational prototypes of a V/STOL tactical transport for tri-service evaluation. This paper presents a description of the flight control and stability augmentation systems. Special emphasis is placed on the programmed functions which are characteristic of VTOL airplanes. Proposed changes in the control systems of production models of the C-142 are identified, and the simulation and flight test programs are outlined.

The XB-70A represents the most advanced example of the evolution and technological advances of manned aircraft in the past decade. It is, in effect, the forerunner of SST type aircraft and in itself is responsible for many items or features that have been subsequently embodied in contemporary military aircraft. This paper describes the unique aerodynamic concepts and configuration of the XB-70A and its airborne systems. Results of the current flight test program are summarized along with discussions on “gremlin” areas during fabrication and flight testing, and how they were or are being solved. Examples of improvements in air vehicle No. 2 as a result of air vehicle No. 1 experience are presented, including a summary of major system reliability demonstrated during the flight test program as an indicator of the potential refinements in cost and performance possible for future large high-speed aircraft.

Planning for ground servicing and maintenance started in the proposal phase and has been followed by test program experience with the XB-70 Mach 3 air vehicle. Servicing and associated safety requirements are summarized. Discussion of maintenance and support actions includes mention of equipment provided to meet the requirements. Preflight, postflight, and periodic operations are outlined, along with some indication of changes that resulted when plans were put into practice. The demands of a high performance flight test air vehicle limit movements toward simplification.

The X-Wing concept employs a single lifting system for all modes of flight. The lifting system is comprised of four very rigid, circulation control wings with blowing for lift modulation and control. For hover and low speed flight, the wings rotate such as the rotor of a helicopter. For high speed flight, the wings are stopped in an “X” configuration across the fuselage - from which the name of the concept is derived - with two forward-swept wings and two aft-swept wings. Such a vehicle is also envisioned to have an integrated gas turbine propulsive system for all flight modes. At low speeds, the gas generators) would drive a shaft to turn the wings and the circulation control compressor as well as a set of propulsive fans. For high-speed flight, the shaft would drive only the compressor and accessories as the fans propel the vehicle. The X-Wing concept has been underdevelopment for over 15 years.

The X-36 is a remotely piloted 28% scale model of a two-axis-unstable notional future fighter aircraft with canards, a mid-wing and features the absence of any vertical control surfaces, Figure 1. The aircraft was jointly developed by the NASA Ames Research Center and McDonnell Aircraft & Missile Systems and flight tested at the NASA Dryden Flight Research Center. Objectives of this program were to demonstrate fighter aircraft agility for a vertical tailless configuration and to demonstrate the development of a low cost alternative to full size prototype aircraft. This paper presents some aspects of the subsystem integration methodology used to develop the X-36 Tailless Agility Research Aircraft.

Agile aircraft (X-29, X-31, F-18 High Alpha Research Vehicle, & F-16 Multi-Axis Thrust Vector) test pilots, while flying at high angles of attack, experience difficulty predicting their flight path trajectory. To compensate for the loss of this critical element of situational awareness, the X-31 International Test Organization (ITO) installed and evaluated a helmet mounted display (HMD) system into an X-31 aircraft and simulator. Also investigated for incorporation within the HMD system and flight evaluation was another candidate technology for improving situational awareness - three dimensional (3D) audio. This was the first flight test evaluating the coupling of visual and audio cueing for aircrew aiding. The focus of the endeavor, which implemented two visual and audio formats, was to examine the extent visual and audio orientation cueing enhanced situational awareness and improved pilot performance during tactical flying.

The X-29A is the first X-series experimental aircraft developed in the United States since the mid-sixties. The X-29A is a technology demonstrator aircraft that integrates several different-technologies into one airframe. Among the technologies demonstrated are the aeroservoelastically tailored composite forward swept wings, close coupled canards, discrete variable camber wing, triplex digital flight control system with analog backup, thin supercritical wing, three surface pitch control, large negative static margin and the integration of these technologies into the X-29 airframe. This paper deals with the issue of technology integration of five of the X-29A subsystems and the early design decision to use existing aircraft, components whenever and wherever possible. The subsystems described are the X-29 aircraft Hydraulics System, the Electrical Power System, the Emergency Power System, the Aircraft Mounted Accessory Drive and the Environmental Control System.