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Presented in this paper is a brief review of momentum exchange theory for Jet Noise Suppression. “Experimental Results from Scale Model Tests” are included. These data exhibit peak to peak attenuation of 20 db along maximum exhaust noise azimuths at a nozzle pressure ratio of 3.1.

SOME POSSIBILITIES for shortening the field length requirements of present-day jet aircraft are: Install leading-edge, high-lift devices which are retrofitable to present-day aircraft. Retrofit — or purchase new — aircraft powered by turbofan engines. These have an inherently higher take-off thrust to cruise thrust ratio than the jets, which vastly improves the take-off acceleration. Use boundary-layer control actuated by turbine discharge gas for immediate consideration in new aircraft engines. Use direct-lift jet engines. These will improve the block speed characteristics of the aircraft and also give vertical take-off and landing capabilities. This paper discusses the advantages of each of these possibilities. The author also describes the problem of airport location within a city, and its effect of total travel time.*

THE FIRST YEAR of jet airline operation has brought many problems — and satisfactions — to the industry. Here the author discusses some of the more serious problems: 1. Scheduling. American Airlines used the “Monte Carlo” method to calculate payloads and flight times. 2. Baggage handling. Almost nothing annoys a passenger more than long waits for baggage at the end of a flight. One approach to the problem is the baggage expediter system. 3. Mechanical shutdowns. 4. Runway length. 5. Noise. Noise suppressors have not been effective enough, from the standpoint of communities surroundings airports. Development of the turbofan engine offers some hope in this area.*

THE optimum mode of control for an aircraft engine is dependent on both the configuration of the engine and its application. Each engine application requires several detail modes of control, one for each definable regime of operation of the engine. Discussions of control requirements can be simplified by classifying these regimes by objectives: physical limiting, thrust, and transient control. The turbojet engine is the basis for the discussion in this paper. Acceptable modes of control can often be selected by inspection of the engine and its application. Selection of an “optimum” control mode requires investigation of the operation of the engine and weapons system at every stage of its use. The selection of a “mode” of control requires a compromise between performance and other design factors. The need for simplicity and accuracy must be balanced against the stability requirements. The availability and flexibility of control components may limit the modes of control considered.

THE NEED for greater speed in military aircraft and missiles is, without question, the primary force behind the current quest for lubricants of increased thermal and oxidative stability. Turbojet engines soon to be available will require improved lubricants for trouble-free operation. Once developed, these oils may find use in the engines of future civilian aircraft as well as in a variety of special applications. It is the purpose of this paper to discuss the results of an experimental program in the field of high-temperature lubricants. Problems of relating chemical structure to the physical properties and performance of highly fluorinared ester lubricants will be described. Background information in the field of turbojet engine lubrication will be presented.

SUBSTANTIAL POWER is necessary to start the modern jet engine. Thus, starting equipment has become a major concern of air transport operators. This paper discusses the equipment used with self-contained starting systems. The authors discuss and evaluate a variety of self-contained systems: combustor, fuel-air combustion, cartridge, liquid propellant, hydraulic supported by auxiliary power units, and electric supported by APU. Possible future systems are: self-breathing systems, oxygen combustors, and liquid-oxygen-water-fuel combustors. It is emphasized that the choice of a starting system for a particular aircraft will depend on aircraft characteristics and the aircraft's intended use.*

This SAE Aerospace Standard (AS) covers 6-point and 12-point flare nut crowfoot, flare nut wrenches, double end flare nut wrenches, combination box end and flare nut wrenches, combination open end and flare nut wrenches, and ratcheting flare nut wrenches that are designed with the following requirements: (a) non-distorting usage; (b) possessing the strength, clearances, and internal wrenching design to be used on hydraulic tube fittings that conform to the requirements of SAE J514 and ISO 8434-2; and (c) transmitting torque to tube fittings without bearing on the apex of fitting wrenching points. Inclusion of dimensional data in this document is not intended to imply that all of the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes.

Instrumentation that has been used for characterization of mixed-phase and glaciated conditions in the past, like the OAP probes, are subject to errors caused by variations in diffraction on the images away from the object plane and by the discrete nature of their particle detection and sizing. Correction methods are necessary to consider their measurements adequate for high ice water content (IWC) environments judged to represent a significant safety hazard to propellers and turbofan engine operability and performance. For this reason, within the frame of EU FP7 HAIC project, instrumentation characterization and validation is considered a major element need for successful execution of flight tests campaigns. Clearly, instrumentation must be sufficiently reliable to assess the reproducibility of artificial clouds with high ice water content generated in icing tunnels.

To recommend supplementary design criteria to enhance the endurance, reliability, and dependability of transport aircraft wheels and brakes.

To recommend supplementary design criteria to enhance the endurance, reliability, and dependability of transport aircraft wheels and brakes.

The purpose of this SAE Aerospace Standard is to provide guidelines for the components and configurations that define the research and commercial versions of the Weather Support to Deicing Decision Making (WSDDM) winter weather nowcasting system.

This document shall be used in conjunction with: - AS6286, Training and Qualification Program for Deicing/Anti-icing of Aircraft on the Ground - AS6286/1, Processes including Methods - AS6286/2, Equipment - AS6286/3, Fluids - AS6286/5, Health, Safety and First Aid - AS6286/6, Aircraft Deicing/Anti-icing Diagrams, No-Spray-Zones

The two combustion products which future technology will be unable to eliminate from present day jet engines are carbon dioxide and water vapor. The potential climatic change effects of carbon dioxide are considered to be a small part of a larger CO2 problem. Water vapor added to the troposphere forms contrails. The paper will assess the non-conclusive evidence of increased cirrus cloudiness at certain locations. Finally the potential climatic effects of added water vapor in the stratosphere on the radiation budget, the small decrease in ozone, and polar night cloudiness is evaluated in the light of future commercial aviation injections of water vapor.

Scope is unavailable.

To recommend supplementary design criteria to enhance the endurance, reliability, and dependability of transport aircraft wheels and brakes.

This new Aerospace Recommended Practice will serve as a practical resource that offers guidance to both the machine operator and Process Engineer for isolating the source(s) of non-repeatability in measured unbalance data. The content of this standard addresses: • Vertical Dynamic Machine Capability to achieve the specified unbalance tolerances and repeat within those tolerances • Tooling Capability to repeat within the specified unbalance tolerances • Rotor characteristics that may preclude repeating within the required unbalance tolerances.

Variable cycle engines (VCEs) hold promise as an enabling technology for supersonic business jet (SBJ) applications. Fuel consumption can potentially be minimized by modulating the engine cycle between the subsonic and supersonic phases of flight. The additional flexibility may also contribute toward meeting takeoff and landing noise and emissions requirements. Several different concepts have been and are currently being investigated to achieve variable cycle operation. The core-driven fan stage (CDFS) variable cycle engine is perhaps the most mature concept since an engine of this type flew in the USAF Advanced Tactical Fighter prototype program in the 1990s. Therefore, this type of VCE is of particular interest for potential commercial application. To investigate the potential benefits of a CDFS variable cycle engine, a parametric model is developed using the NASA Numerical Propulsion System Simulation (NPSS).

Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions.