Browse Topic: Thrust reversers

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Custom Flexible ShaftsTBMG-3336212/01/2018
S.S. White Technologies St. Petersburg, FL 727-626-2800
Using Electromagnetic Brakes to Keep Thrust Reversers IN PLACETBMG-3301810/01/2018
Applying reverse thrust redirecting engine power to oppose the direction of travel is a standard technique for decelerating aircraft after touchdown. The approach saves wear on the brakes of the landing gear wheels and reduces stopping distance. Although accidental deployment of the thrust reverser cowl could and did happen, it was assumed for decades that this would only present a hazard in the moments around takeoff and landing. With changes to engine design and aircraft aerodynamics, this assumption no longer held, as demonstrated by the catastrophic loss of Lauda Air Flight 004.
Tech Briefs: October 201818AERP1010/01/2018
Detecting Drones with Doppler-Based Radar Digital Transformation for a Connected Enterprise Using Electromagnetic Brakes to Keep Thrust Reversers in Place Thermostatic Solutions for Temperature Control Applications Bringing RF into the Embedded World: It's Time Compact Power Amplifier Solution for Electronic Warfare Burner Rig Testing of A500® C/SiC Test method simulates, in a laboratory environment, the service conditions ceramic-matrix composite material would experience in turbine engine exhaust applications. Space Debris Orbit and Attitude Prediction for Enhanced and Efficient Space Situational Awareness Developing accurate models to predict the behavior of manmade debris in space could be the key to preventing collisions with satellites. Maintaining Enterprise Resiliency Via Kaleidoscopic Adaption and Transformation of Software Services (MEERKATS) Implementing new technologies to create a more resilient, secure cloud computing environment. Fundamental Aspects of Single Molecule
Reverse ThrustAIR6064 (Current)05/07/2018
Propulsion measurements and thrust methods presented in the current published versions of AIR1703 and AIR5450 place a primary focus on the engine reactionary force (thrust) acting to propel an aircraft in the forward direction. In contrast, this document addresses the use of the engine reactionary force in the opposite direction (reverse thrust) to supplement aircraft deceleration. This document’s application spans commercial and military transport turbofan engine applications for various engine and reverse thrust configurations. The discussion and examples primarily focus on separate flow exhaust turbofan engines. Piston and turboprop variable-pitch propeller blade applications are not covered. Although reverse thrust has been utilized for in-flight deceleration, primarily for short takeoff and landing aircraft and military fighter applications, this application of reverse thrust is only covered in a cursory manner.
E-33 In Flight Propulsion Measurement Committee
Composites design optimization for automated fiber placement15MEIP03_0303/01/2015
Coriolis Composites and SAFRAN Aircelle worked together on a thrust reverser component demonstrator made with carbon-fiber-reinforced plastic (CFRP) material and an AFP process. Complex composites structures are becoming more common, especially in aeronautics. Composites preforms can now be manufactured by automated processes, such as automated fiber placement (AFP) and automated tape laying (ATL), to achieve the expected production volumes. The AFP process is the most interesting since it can address complex double-curvature layup surfaces with good productivity rates and low material scrap, according to Coriolis Software. The main advantages of this technology are that material can be steered to address the problem of curvature, and fiber angular deviation from the engineering rosette can be easily managed. This opens interesting possibilities to optimize the design of composites structures and to change the current traditional “black metal” approach of design offices.
Composites Design Optimization for Automated Fiber Placement Process2014-01-226109/16/2014
Today, the design and optimization of complex 3D composites structures is managed by taking into account engineering and manufacturing constraints. If the manufacturing process is automated, especially using a robot, these constraints are particularly complex and a difficult compromise needs to be reached. Most of the technology available on the market, dedicated to automated processes offline programming, neglects some of these constraints, or can only highlight the manufacturing defects without any automatic or manual tools to solve the tape course programming issues. A new innovative approach has been developed to include engineering, material and process specifications, to help designers and NC programmers to optimize the final layup program in terms of structural properties and productivity rate. An aerospace case study using the automated fiber placement (AFP) process will be presented to highlights these offline programming capabilities.
Blanchard, Yvan
Power Electronic and Powerplant Environment2013-01-208109/17/2013
The power plant is the area in an aircraft where they are a lot of power conversion. The power plant is the core of the aircraft from energy point of view. The engines allow to take off but not only, it also provides energy to the aircraft from many different manners. They are electrical, hydraulic, mechanical, …. The power plant is definitively a power generator but also a power consumer. Since now some years, the power electronic technology is spread into the aircraft. One can say that some pedigree has been collected with this technology embedded to the aircraft. For the power plant domain, it is different. This technology is really not usual for use. Our environment is really not friendly and even if the integration of the power converters has been improved over the last years, there is not a lot of space around the engines. These are probably the mains reason of the low deployment of the power electronic in this domain but not only. The reliability of the thrust function is
Ambroise, Richard
Automatic Braking System (ABS)ARP4102/2A (Current)07/31/2012
This document recommends design criteria for an Automatic Braking System. The ABS shall enhance braking performance under most aircraft configurations and all runway conditions.
S-7 Flight Deck Handling Qualities Stds for Trans Aircraft
Appendix C Electronic Display Symbology for Engine DisplaysARP4102/7_APXC (Current)07/10/2007
S-7 Flight Deck Handling Qualities Stds for Trans Aircraft
Automatic Braking System (ABS)ARP4102/2 (Historical)06/23/2004
This document recommends design criteria for an Automatic Braking System. The ABS shall enhance braking performance under most aircraft configurations and all runway conditions.
S-7 Flight Deck Handling Qualities Stds for Trans Aircraft
Monolithic Structure Affordability: 737 Classic Versus Next Generation2003-01-290909/08/2003
One recent evolution in commercial transport structure has been the emergence of monolithic structure applications. Monolithic structure reduces the number of parts that must be managed, eliminates sub-assembly operations and contributes strongly to determinant assembly practices. The cost of three components from the Boeing 737-200 and their counterparts on the Boeing 737-600 will be compared. The mid 1960's 737-200 components were assembled from sheet metal details. The mid 1990's 737-600 components are monolithic designs and utilize superplastic forming, casting and NC machining technologies. The built-up solutions and the monolithic solutions are compared based on cost infrastructures from the 1960's and the 1990's.
Weber, Gary R., Morgan, Jeffrey D.
Cessna establishes its SovereigntyAEROAPR02_0604/01/2002
The company finalizes development of the Sovereign and prepares it for FAA certification, which is expected late this year. Engineers at Cessna Aircraft Co. recently conducted the first engine run for the Sovereign. The aircraft's power plant is one of the few remaining systems being tested prior to first flight, which is scheduled for early spring. FAA certification is expected to be awarded in late 2003, with customer deliveries beginning in early 2004. The Sovereign will be powered by two Pratt & Whitney PW306C engines, each with a takeoff thrust of 5686 lb flat-rated to ISA +15°C, enabling a cruising speed of up to 444 kts. Controlled by dual Full Authority Digital Electronic Control (FADEC) systems and using a single-pivot thrust reverser design, the engine has 3000 h HIS and 6000 h TBO maintenance intervals. The company has finalized the design of the aircraft's engine nacelle assembly, which consists of the engine cowling, inlet assembly, throttle quadrant, and thrust reverser
A Paradigm for Developing Operational Decision-Making (ODM) Training2001-01-302709/11/2001
The views and opinions expressed in this paper are solely those of the authors. They do not necessarily represent the positions or policies of any private, public or governmental organizations. Over the past 8 years, the authors have been developing a training-oriented paradigm for operational decision-making in the cockpit. While our emphasis has been on the civil aviation side, the model can easily adapted for the business aviation venue. The paradigm began to form at an aeronautical decision-making workshop in 1992 (Lofaro, Adams and Adams; 1992) around an expanding set of interrelated concepts. The set expansion resulted from the authors continuing to wrestle with identifying and explicating the critical components and processes for real-time operational decision-making, as well as the relationships among decision-making, crew resource management (CRM) and situation awareness (SA). The first paradigm component was the “rising risk continuum” (Lofaro and Smith, 1993), as embedded in
Smith, Kevin M., Lofaro, Ronald John
Solution of an Engine Inlet Compatibility Problem During C-17 Low Cost N/EAT Nacelle Thrust Reverser Development2000-01-557910/10/2000
The C-17 transport aircraft is established in military service with unique capabilities to ground maneuver using thrust reversers. Recently, the C-17 has undergone fan thrust reverser re-design to reduce cost. The new Nacelle/Engine Affordability Team (N/EAT) nacelles are now fully qualified but had, during the flight test program, revealed an engine inlet compatibility problem. Flight tests, engineering analyses and practical applications that led to a successful N/EAT fan reverser cascade design modification are discussed. Fabrication methods that enabled timely implementation of the solution and flight test results showing successful resolution of the problem are presented.
Johns, Christopher J.
The 3x Jet Engine Configuration95117305/01/1995
An advanced, unconventional two-engine jet configuration shows considerable promise of significantly reducing operating costs, dramatically improving two-engine climb performance, extending range and increasing safety.
Bacon, Richard, Roskam, Jan
High Bypass Separate Flow Exhaust System Improved Thrust Efficiency By Modifying the Aft Centerbody93262209/01/1993
Scale model data indicated a performance dip in nozzle thrust efficiency at the cruise design conditions for a high bypass separate flow derivative exhaust system. A performance improvement program was implemented to determine the cause of the reduction in thrust efficiency and to identify viable redesigns. Data analysis indicated the performance loss to be a result of high Mach number fan and core exhaust interactions adversely affecting the pressure force on the exhaust system centerbody. Scale model testing confirmed the cause of performance loss and demonstrated that modifying the aft centerbody to reduce the plume Mach number recovers the loss in exhaust system thrust efficiency.
Babbitt, Bob
Nacelle Automatic Riveting92241910/01/1992
Increasing world competition is forcing U.S. industry to find new ways to not only survive, but excel, in the rapidly expanding global economy. The production side of manufacturing currently faces pressure to keep down cost and, at the same time, improve quality. The use of increasingly powerful, yet flexible, part-handling/positioning systems, along with their associated automatic riveting machines, can help. A semirobotic part-positioning system and elevated automatic riveter used for the assembly of aircraft engine nacelles and extremely contoured panels including control schemes, applications, and implementation are discussed.
Pekar, Gary W.
A Study of Decision Making and Performance in Rejected Takeoffs92113407/01/1992
A study was conducted in a B-737 full flight simulator at the Boeing Customer Training facility to evaluate pilot decision making and performance under various situations in which decisions on whether or not to reject a take off had to be made and executed. A total of eight (8) situations were defined in which Go/NoGo decisions had to be made near V1 speed. Subjects included 24 Boeing instructor pilots and 24 line pilots from five different airlines. The sequence in which pilots encountered the situations was carefully balanced across subjects to control for learning effects. The results of the study are reported as quantitative data on RTO decisions, stopping performance, and procedure accomplishment plus a summary of data derived from post-run debriefings of the airline pilots. Lessons learned, conclusions, and recommendations for RTO training are presented.
Roberson, William C., Shontz, William D.
Results and Lessons Learned from the STOL & Maneuver Demonstration Program91200509/01/1991
The STOL and Maneuver Technology Demonstrator (S/MTD) Program has validated a set of technologies that give a supersonic fighter all-weather Short Takeoff and Landing (STOL) performance while also enhancing up-and-away maneuverability. Significant reductions in both takeoff and landing distances, compared with the unmodified F-15, have been measured. The additional pitch control power of thrust vectoring has been demonstrated up to 30° angle of attack. The effectiveness of up-and-away reversing has been identified. First, major flight test results are presented and then lessons learned from this integration program are discussed.
Moorhouse, David J., Laughrey, James A.
Use of Thrust Vectoring and Reversing on the S/MTD91117304/01/1991
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.
Laughrey, J. A.
Factors Affecting Pilot Decision-Making in Rejected Takeoffs90234412/01/1990
Runway overruns following high speed rejected takeoffs (RTOs) have resulted and continue to result in airplane incidents and accidents. Although most high speed RTOs are executed without incident, the potential for an incident or an accident remains high. Since 1988 for example, four high speed RTO incidents and accidents occurred, two of which resulted in destroyed airplanes and one of those, fatalities. In response to the RTO incidents and accidents, the National Transportation Safety Board issued a Special Investigation Report which examined training and procedures used in the recognition of the need for and the execution of high speed RTOs. This report examines the pilot decision-making aspects of initiating and executing an RTO that were found in the Special Investigation. It discusses the deficiencies found in pilot training and procedures as well as recommendations offered to address those deficiencies.
Strauch, Barry
Carbon Epoxy Perforated Skin for Nacelle Acoustic Treatment90198209/01/1990
The acoustic treatment requirement for jet engine nacelle inner flowpath leads to using perforated skin. Formerly in light alloy these skins are now composite and new techniques have been developped to achieve the perforation. After reviewing different possible techniques (mandrel tool, abrasion, stamping, mechanical drilling,…) one process is chosen and described in terms of skin mechanical properties, cost, and production facilities.
Hersen, R., Vigneron, D.
Advanced Materials and the Pivoting Door Reverser90198609/01/1990
HUREL-DUBOIS patented a new concept of thrust reverser in 1981 known as “the door forward reverser”. It gives numerous advantages over the conventional cascade reverser, and in particular is inherently lighter. The extensive use of advanced materials has allowed a highly competitive weight to be achieved. This paper describes the work currently under way for the pivoting door reverser for the ROLLS-ROYCE Trent engine and covers: Thrust Reverser door structure predominantly in composite. Acoustic treatment with composite sandwich. IFS design with carbon bismaleimide material This reverser will be used on MD11 and Airbus A330 aircraft.
Fourrier, Alain, Jouan, Jean-Alain
Fire Barrier Coatings and Their Uses90095704/01/1990
Fire barrier coatings are being used to protect nacelle and cowling components by insulating the surfaces from excessive heat exposure during normal flight operations and to provide a fire barrier in the event of an engine fire. Design criteria, formulating, considerations, application methods, and typical performance characteristics for such systems will be discussed.
Brannfors, J. E.
Propulsion Integration for Military Aircraft89223409/01/1989
ABSTRACT The transonic aerodynamic characteristics for high-performance aircraft are significantly affected by shock induced flow interactions as well as other local flow interference effects which usually occur at transonic speeds. These adverse interactions can not only cause high drag, but can cause unusual aerodynamic loadings and/or severe stability and control problems. Many new programs are underway to develop methods for reducing the adverse effects, as well as to develop an understanding of the basic flow conditions which are the primary contributors. It is anticipated that these new programs will result in technologies which can reduce the aircraft cruise drag through improved integration as well as increased aircraft maneuverability through the application of thrust vectoring. This paper will identify some of the primary propulsion integration problems for high performance aircraft at transonic speeds, and demonstrate several methods for reducing or eliminating the
Henderson, William P.
RB211 Developments87240911/13/1987
This paper examines briefly the growth prospects of long haul civil air transportation in the Pacific basin and the contribution made by the RB211-524 in the Boeing 747. The development of the latest committed version of this engine giving over 60,0001b static thrust is described as well as the design of the proposed 65,0.001b static thrust RB211-524L powerplant. Finally the prospects for new Ultra High Bypass Ratio cowled turbofans for long haul operation in the next century are reviewed.
Pickerell, D. J.
Applications of Advanced Upper Surface Blowing Propulsive-Lift Technology82095602/01/1982
The National Aeronautics and Space Administration has conducted research on propulsive-lift techniques for more than 30 years. The success of the flight research program conducted with the Quiet Short-Haul Research Aircraft led to studies of this technology for a business jet and a Short-Haul Transport application. The studies showed that the Short-Haul Transport could operate from a 2500-ft (762.0 m) runway with 95 passengers at low noise levels. Design range was 500 n. mi. but with maximum fuel load the runway length is only increased to 2900 ft (883.9 m) while the range is increased to more than 1000 n. mi. Two business jet designs were studied; one design was based on a 1500-ft (457.2-m) field length and the other was designed for a 2500-ft (762.0-m) field length. As with the Short-Haul Transport, the business jet designed for a 1500-ft (457.2-m) field length can be loaded to maximum fuel capacity. In this case the range increases from 500 n. mi. to 1400 n. mi. while the runway
Cochrane, John A., Riddle, Dennis W.
Tactical Air-to-Surface Requirements for the 1990s81109810/01/1981
PROJECTIONS OF REQUIREMENTS FOR MANNED, TACTICAL AIR-TO-SURFACE SYSTEMS in the 1990’s must consider a number of complex issues involving future scenarios; threat environment; force mix; emerging technology in weapons, avionics, and airplane design; and operational concepts. The purpose of this paper is to provide a brief overview of some of the future requirements that may change current design approaches and concepts of operation. Parametric trades and design considerations on such issues as range-payload, short takeoff and landing (STOL) requirements, autonomous versus nonautonomous systems, and air-to-air versus air-to-ground requirements are summarized. Airplane design and technology requirements having application to the resulting requirements are identified, and an example of a possible future tactical air-to-surface fighter is described.
Caldwell, A. L.
Cleaner, Thrust Reverser, Water-BaseAMS1540 (Historical)07/01/1981
This specification covers a water base cleaner in the form of a liquid.
AMS J Aircraft Maintenance Chemicals and Materials Committee
Reverse Thrust Performance of the QCSEE Variable Pitch Turbofan Engine80119609/01/1980
Results of steady-state reverse and forward-to-reverse thrust transient performance tests are presented. The original QCSEE 4-segment variable fan nozzle was retested in reverse and compared with a continuous, 30° half-angle conical exlet. Data indicated that the significantly more stable, higher pressure recovery flow with the fixed 30° exlet resulted in lower engine vibrations, lower fan blade stress and approximately a 20% improvement in reverse thrust. Objective reverse thrust of 35% of takeoff thrust was reached. Thrust response of less than 1.5 sec was achieved for the approach and the takeoff-to-reverse thrust transients.
Samanich, N. E., Reemsnyder, D. C., Bloomer, H. E.
State of the Art of Spherical Roller Bearings79085002/01/1979
The historical evolution of the spherical roller bearings is discussed briefly. The difrent internal and external designs common in today's market are evaluated regarding their load carrying ability, roller guidance, and friction. It can be shown that all these criteria have to be evaluated simultaneously with a view towards the application conditions expressed by the load magnitude, load angle, load direction changes, speed, speed changes and mounting conditions. It can also be shown that the method of guiding the rollers by means of a retainer or by means of an integral center flange are equally valid and equally efficient methods under most application conditions. In cases of extreme application conditions, however, it is evident that the positive guidance of the rolling elements through an integral centerflange will result in lower friction, i.e. better running conditions. It is also shown that other design factors besides the retainer and center flange are available such as the
Wieland, Walter P., Poesl, Wolf
Chrysler's New 300 Sterndrive77071302/01/1977
A new compact, attractively styled, light weight, high performance sterndrive has been developed to meet future needs of boat builders and consumers. This drive incorporates a new patented “inverted yoke” suspension system that provides excellent steering and handling characteristics. A new patent protected self-energizing cone clutch and novel shift mechanism produces smooth, quiet shifting in a very compact package. The new and unique above-cavitation plate exhaust provides increased reverse thrust and low level exhaust noise. Other features include ease of installation, good fuel economy, and overall superior performance.
Hurst, John W.
The OMC 200 Hp V-6 Outboard Motor76064302/01/1976
This paper summarizes the objectives and choices for various design alternatives in making a 200 horsepower production outboard motor. The discussion covers the choice of cylinder arrangement, selection of scavenging process, intake system, exhaust tuning system and cooling system operation. Other areas covered include hydrodynamic considerations for gearcase design, development of a new isolation system, a new hydraulic trim and tilt system, general structural requirements and considerations for corrosion protection.
Hall, Charles B., Nerstrom, James S.
OMC Sail Drive-Hybrid Propulsion System for Cruising Sailboats76067502/01/1976
The cruising sailboat of 22 to 30 feet (7 to 9m) in length has been customarily powered by outboard motors, or small gasoline, or diesel inboard engines. This paper describes the recently introduced OMC Sail Drive propulsion unit which combines the simplicity and light weight of the two-cycle, two-cylinder outboard motor powerhead with a close coupled lower gearcase and propeller for fixed inboard installation in sailboats. Installation, design parameters and performance data are included.
Lambrecht, Ralph E.
Design, Development and Flight Test of the Cessna Citation Thrust Reverser76046802/01/1976
Design, development and testing thrust reversers for a business jet airplane are described from program conception through Federal Aviation Administration (FAA) Certification. Mechanical design, reverser operation, failsafe features, actuation systems and aircraft integration are covered. Model tests, developmental taxi tests, static ground tests and flight tests required for configuration development and FAA type certification are discussed.
Allen, Alvin C., Wickline, Robert J.
Thrust Reversers for the TFE-731 Turbofan75050602/01/1975
Improved design features have made the pivoted-target thrust reverser concept most attractive for modern small turbofans with coaxial flow exhaust systems. These aerodynamic, mechanical and structural design improvements provide 40% or more reverse thrust effectiveness in a simple, light weight, low cost unit that has clean aerodynamic lines and minimum effect on engine performance. The pivoted-target thrust reverser system, under development at Grumman for the AiResearch TFE-731-2 and -3 engines, is described. Applications include the IAI Westwind 1124, the Gates Learjet 35/36 and the Dassault Falcon 10 aircraft.
Greathouse, William K., Martin, Sherman F.
Optimizing Transmission Bearing Selection and Assembly75085702/01/1975
Optimizing bearing selections for transmissions requires accounting for environmental differences between laboratory conditions used in rating the bearings and actual field conditions where the bearings will be used. Assembly methods become an important part of optimizing the design.
Hacker, R. W., Cuming, W. R.
Water Jet Propulsion - Competition for Propellers?74028302/01/1974
The increasing acceptance of water jet propulsion as an alternative to propeller drive in recreational size boats is evaluated on the basis of advantages and disadvantages to the consumer. Comparative performance data for water jet and inboard-outboard propulsion units powered by identical engines installed in identical boats are presented. These include data on fuel mileage, speed, and acceleration with various loads, engine rpm versus boat speed, and horsepower requirements.
Lambrecht, Ralph E.
Effects of STOL Thrust Reversers and Powered Lift on Inlet Flow Quality74045702/01/1974
An experimental test program was conducted to determine the engine environment which results from STOL operation with blown flaps and thrust reversers. Testing was conducted in a low speed wind tunnel with a 1/11 scale model of a STOL transport consisting of a fuselage and high-lift wing with triple-slotted externally blown flaps, leading edge slats, and powered model engines. Steady-state and dynamic total pressure distortion were moderate at takeoff and approach conditions with blown flaps. The cascade type STOL thrust reversers tested produced severe dynamic distortion due to unstable interactions of the reversed streams with the oncoming flow and vortex ingestion. Comments on methods to alleviate these problems are presented.
Sherman, Dale A., Usab, William J.
Waterjet Propulsion for High Speed Jets74028102/01/1974
Waterjet propulsion and its optimization for modern water crafts were considered and some comparisons were made between waterjets and propellers. The waterjet optimization process presented includes considerations of inlet drag, weight of the propulsor, and the effect of the head and flow rate design parameters of the waterjet on the range of the craft. The waterjet/propeller comparison showed that the waterjet is the preferred propulsor in applications of high and intermediate speed, applications requiring high maneuverability, and applications requiring shallow draft and immunity to water-borne debris.
Rudnicki, M. I., Sjogren, R. G.
The Concorde Manufacturing Consortium - An Exercise in International Engineering Collaboration73035002/01/1973
This account of the development of the Concorde and its eventual manufacture is highlighted by the cooperative efforts of two dissimilar countries, brought together by a singular vision and united by a determination to create a practicable design of a mass-transport aircraft. The innumerable problems encountered cannot be completely covered in this capsule history, but the overall review given here presents a new approach toward solving the economic troubles of the air transportation industry, which may possibly be affected by impractical competitive practices.
Burgess, E. H.
PROPULSION TECHNOLOGY ADVANCES NEEDED FOR A QUIET SUPERSONIC TRANSPORT73089802/01/1973
Operation of a U.S. developed supersonic transport must and will meet community noise standards. This paper examines the airport noise problems of large transport aircraft, highlights critical considerations, and then studies possible solutions available from advanced propulsion technology. Engine sizing requirements to meet SST payload-range and airport performance criteria are reviewed first, and the impact of noise on the engine size and aircraft performance is then identified. Relief offered by noise suppressor development and technology advances that can be foreseen in the next decade for turbojet and turbofan engines are described. The advantages offered by a duct heating turbofan engine cycle are discussed. The potential offered by variable cycle engines to provide low noise characteristics with minimum penalty on performance are shown, and the practical restraints imposed on this potential by airframe aerodynamic noise is illustrated. The importance of supporting engine
FOSS, RICHARD L., BRAGDON, ELLWOOD L.
Aircraft Noise and the Airlines72062102/01/1972
United States airlines are deeply concerned about the problem of aircraft noise, and have been actively involved in developing methods of abatement. There are three basic approaches that may be taken to handle this problem: reduction of noise at the source, operational procedures, and control of land use in the vicinity of airports. Aircraft noise is a problem that will be solved only through massive cooperative effort and federal funding. And it should be remembered in any suggested solutions that maintenance of the highest safety standards must be the overriding consideration.
Becker, William B.
Prop-Fan - A High Thrust, Low Noise Propulsor71047002/01/1971
The Prop-Fan is introduced as a new propulsor type, intermediate between ducted propellers and low bypass fans. Compared to today's fan engines, it offers approximately twice the takeoff thrust/hp at half the tip speed and consequently much reduced noise level. Furthermore, its controllable pitch feature provides more effective reverse thrust at about one-fourth the weight of current flow reversers. Prop-Fan characteristics are particularly well matched to the propulsion requirements of advanced STOL transport aircraft. Highlighted is the uniquely low noise signature of the Prop-Fan. This now permits the design of medium-to-long range STOL transports of high-productivity which will meet the stringent noise level limits for STOL-ports. The paper describes the development status of the Prop-Fan, examines potential aircraft installation arrangements, and presents some representative STOL transport effectiveness comparisons.
Rosen, George
Engine Selection Problems for Jet Powered Ultra STOL70026602/01/1970
This paper discusses the effect of engine size and cycle on two types of Ultra STOL aircraft. One type, a powered lift plus deflected cruise thrust vehicle, is analyzed to determine the effect of wing loading, cruise engine, lift engine thrust loading, number of lift engines, cruise engine bypass ratio, and turbine inlet temperature on airplane gross weight and cost at a 1000-ft field length. The other type, a conventional nondeflected thrust airplane, is analyzed to determine the effect of wing loading, thrust loading, engine bypass ratio, and turbine inlet temperature on airplane gross weight and cost at field lengths from 1000-2000 ft. Results of this analysis indicate that powered lift aircraft are not cost competitive unless field lengths of less than 1000 ft are considered.
Axelson, D. H., Upton, G. G.
Electric Thrust Control System for Supersonic Transport Power Plant70081902/01/1970
The design of the propulsion control system for the Supersonic Transport (SST) is a culmination of three years of design trade studies. An analysis was made of the throttle systems of the Boeing 747, XB-70, Concorde and other airplanes with a view toward the applicability of these systems for use on the SST. The major considerations that led to selection of a redundant channel electro-hydraulic propulsion control system are: safety, operational-reliability, performance and weight. Presented here is a description of the SST Propulsion Control System which is composed of two subsystems, the Thrust Control Subsystem and the Mode Control Subsystem.
Gorman, Richard F., Morrow, Donald L.
Solid State Proximity Switches/Logic for Aircraft Electrical System Applications70030502/01/1970
The development of solid state proximity switches, sensors, logic and self-test circuits for aircraft electrical applications has led to switching systems for actuators, thrust reversers, and integrated sensor/switch units with improved reliability, maintainability, and simplicity of application. The advantages of proximity switches over medhanical switches, design objectives, operational details, and features of the system are discussed.
Gidlund, T. E.
The Pilot's Choice - Off the End or Off the Side of the Runway69037502/01/1969
As one element of ground operations of aircraft, the current paper indicates the lack of compatibility of actions required under adverse operating conditions. It is shown that for maximum deceleration, the aircraft should be in maximum drag configuration; whereas, for lateral control, minimum drag and forward thrust might be required.
Donely, Philip
The SNECMA Thrust Reverser System of Concorde's Prototypes69041202/01/1969
The particular design of the SNECMA thrust reverser on Concorde results specifically from the general nacelle arrangement, and also from the exhaust system requirements. In this context, the author justifies the present arrangement of the SNECMA thrust reverser system. He describes in detail the technological features and the tests completed, which allowed the thrust reverser system to meet performance, safety, airworthiness, and operational requirements for the flight development phase on the Concorde prototype. In this respect, further consideration is given to the reliability and maintenance aspects, as an important feature of the design.
Caffier, E.
The JT9D Engine Control System69040502/01/1969
The JT9D turbofan engine, soon to be in airline service on the next generation of advanced jet aircraft, will incorporate the Hamilton Standard JFC 68 main fuel control and EVC 3 engine vane control. Now in production, this control system embodies advanced control technology while retaining the basic advantages of present operational systems. Its specific advantages are improvements in weight, performance, reliability, and durability over present commercial jet engine control systems. This paper presents a discussion of the design philosophy used in creating the system, a description of the system and some advanced techniques used in its development.
Bussolari, Robert J.
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