Joint Strike Fighter Research Articles

Transonic Free-To-Roll Analysis of the F-35 (Joint Strike Fighter) Aircraft

The free-to-roll technique is used as a tool for predicting areas of uncommanded lateral motions. Recently, the NASA/Navy/Air Force Abrupt Wing Stall Program extended the use of this technique to the transonic speed regime. Using this technique, this paper evaluates various wing configurations on the Joint Strike Fighter (F-35) aircraft. The configurations investigated include leading- and trailing-edge flap deflections, leading-edge flap gap seals, and vortex generators. These tests were conducted in the NASA Langley 16-Foot Transonic Tunnel. The analysis used a modification of a figure of merit developed during the Abrupt Wing Stall Program to discern configuration effects. The results showed how the figure of merit can be used to schedule wing flap deflections to avoid areas of uncommanded lateral motion. The analysis also used both static and dynamic wind-tunnel data to provide insight into the uncommanded lateral behavior. The dynamic data were extracted from the time history data using parameter identification techniques. In general, sealing the gap between the inboard and outboard leading-edge flaps on the Navy version of the F-35 eliminated uncommanded lateral activity or delayed the activity to a higher angle of attack.

THE F‐35 JOINT STRIKE FIGHTER AS A SOURCE OF INNOVATIon AND EMPLOYMENT: SOME INTERIM RESULTS

The F‐35 Joint Strike Fighter (JSF) programme is important for innovation in the Dutch economy and also contributes to other programmes in the aerospace industry (spin‐off) and other industries (spillover). On top of the expected value of US$9.2 billion in development and production, based on interviews with 10 companies and research institutes, an expected spin‐off of US$1.1 billion and an expected spillover of US$120 million will result. In addition, over 23,000 man‐years are associated with the activities in the development and production of the JSF. This study excludes the large and labour‐intensive Maintenance, Repair and Overhaul (MRO) activities. Further validation of data and an update of current results is planned for 2006.

Flight tests of Distributed Aperture System sensors for F-35 Joint Strike Fighter

Flight tests of Distributed Aperture System sensors for F-35 Joint Strike Fighter

Joining the Pieces

This article focuses on variants of the F-35 Joint Strike Fighter’s airframe and structure required by the services’ different missions. The Air Force needed a tough, lightweight aircraft that could operate from fields close to combat zones. This is the conventional takeoff and landing variant. The Marines needed a plane with short takeoff and vertical landing. This aircraft, which has a 50-inch-diameter lift-fan behind its cockpit powered by the F-35’s turbine engine, has also been ordered by Britain’s Royal Navy and Royal Air Force. Assembly of the F-35 at Fort Worth has been highly automated and centers around three assembly systems. The biggest of them assembles three variants of wings. Standing about 30 feet high, the assembly systems automatically accommodate different components. Subcontractors and other Lockheed Martin plants are handling most of the detailed parts fabrication and subassembly.

Fly like a fly [micro-air vehicle

A team of scientists has built a fly-size flight simulator in an attempt to understand flight control from the perspective of the common housefly. Results so far have shown, and further tests are expected to confirm, that the fly uses a flight control paradigm that is completely different from that of a fighter jet. Whereas the F-35 Joint Strike Fighter takes a few measurements and then plugs them into complex equations, which it must solve in real time, the fly relies on many measurements from a variety of sensors but does relatively little computation. By discovering the fly's flight control scheme, the scientists hope to derive important lessons for the design of micro air vehicles, which attempt to approximate insect flight, and for high-performance aircraft in general.

Joint Strike Fighter Dual-Cycle Propulsion System

The Joint Strike Fighter (JSF) is a family of aircraft that will be built in conventional, naval, and short-takeoffand-vertical-landing (STOVL) variants. The key to the development of this family of aircraft is a new dual-cycle propulsion system, which is used to convert some of the jet thrust to shaft horsepower in order to power a lift fan in the STOVL variant. The theoretical basis for the dual-cycle operation of this engine will be presented. Some results of the engine test and development program conducted by Pratt and Whitney and Rolls Royce and the JSF STOVL flight-test program will also be discussed. Potential future applications of this dual-cycle propulsion concept to STOVL transport aircraft, compound rotorcraft, and for takeoff noise reduction will be described. I. Introduction T HE F-35 Joint Strike Fighter will combine the supersonic performance of the F-16C Falcon with the short-takeoff-andvertical-landing (STOVL) capabilities of the AV-8B Harrier, while providing greater range and increased survivability. There will be three variants: a conventional takeoff-and-landing variant for the U.S. Air Force, a short-takeoff-and-vertical-landing variant for the U.S. Marine Corps and United Kingdom, and a carrier-based variant for the U.S. Navy. These three variants are shown in Fig. 1. The naval variant has a somewhat larger wing, in order to reduce landing speeds for carrier operations. This also gives it somewhat greater range, both by reducing the induced drag and by providing additional volume for fuel. The STOVL variant has a shorter canopy and a slight bulge behind the cockpit. These accommodate a lift fan installed in a bay between the inlet ducts. As shown in Fig. 2, the lift fan is driven by a drive shaft extending from the front of the cruise engine. This lift fan provides 18,000 lbs of thrust, almost half of the total lift in hover. A thrust-vectoring nozzle at the rear of the aircraft deflects the core thrust of the cruise engine, which provides another 17,000 lbs of thrust. A roll control nozzle in each of the wings is fed by fan air diverted from the cruise engine. These provide approximately 2500 lbs of thrust apiece. The two main lift nozzles and the two auxiliary roll control nozzles constitute a two plus two hover lift and control system. The cruise engine is a conventional mixed-flow turbofan, providing more than 25,000 lbs of dry thrust. The lift fan is not connected to the engine during cruise. For STOVL operations, the engine operating point is changed so that its turbine section extracts additional energy from the exhaust jet and converts it to shaft horsepower. This power is delivered to the lift fan by engaging a clutch at the end of the drive shaft extending from the front of the engine. The airplane is controlled in pitch by shifting power between the lift fan and the cruise engine nozzle. The cruise engine nozzle rotates from side to side in order to control the aircraft in yaw. To control the aircraft in roll, the area of the auxiliary nozzle on one side is opened, and the nozzle on the other side is closed. The total thrust remains constant while the thrust of the nozzle pairs are varied to provide control forces.

Aerodynamically Controlled Expansion Nozzle for Short Takeoff and Vertical Landing Aircraft

Introduction T HE propulsion system of a short takeoff and vertical landing aircraft, such as the F-35 Joint Strike Fighter, must operate over a wide range of conditions, provide good fuel efficiency at cruise, and deliver high thrust in augmented mode for transonic acceleration and supersonic operation. The propulsion system must be efficient for both high-speed flight and during hover, while addressing the mechanical complexity required for conversion of the thrust stream from horizontal to vertical. A situation where the desire for mechanical simplicity and high propulsion performance are at odds arises in the exhaust system. The exhaust flow conditions in hover are dramatically different from that in transonic acceleration, yet the nozzle provides the same flowpath in both cases (Fig. 1). Specifically, the nozzle provides an internal expansion ratio of 1.3 to give good performance for the critical transonic acceleration portion of the mission. The same expansion ratio is present in hover and produces overexpansion of the flow, resulting in thrust loss. Reduction of the nozzle expansion ratio to 1.1, however, will increase the gross thrust coefficient C f g at hover from roughly 0.92 to at least 0.96 (Ref. 1). For the three mission points of cruise, transonic acceleration, and hover, nozzle pressure ratio (NPR) values are NPR = 3–4, 6–8, and 2, respectively. The total temperatures are 780 K for cruise and hover and 2000 K for transonic acceleration. An aerodynamic approach appears feasible for the provision of nozzle expansion control. The underlying principle is to displace the primary airflow away from the divergent flap to achieve an effectively smaller nozzle expansion area ratio. Examples of such techniques include the use of slots or vents to admit secondary air2 and the use of ejectors or injectors.3−5 Greathouse and Beale5 showed that the gross thrust coefficient increases with increasing secondary ejector flow, particularly at low

Shipborne Aviation: An Introduction

The evolution of air vehicles for use on board a ship spans a period of nearly 150 years. Starting with observation balloons in the American Civil War, the development has moved to the Joint Strike Fighter, an aircraft of immense technical sophistication and a potent weapon. The design requirements of both ship and aircraft spawn conflicts and the two technologies are now required to work in total unison. This paper discusses the evolution and how the various wars have shaped the most demanding of aeronautical disciplines.

The Jet Age, Continued

The Jet Age, Continued

Aerospace adds lustre to appeal of master alloy MIM feedstocks

The superalloy components used in the new generation jet engines that power such aircraft as Lockheed's Joint Strike Fighter could make commercial common sense for MIM specialists…

Capturing Fortress Europe: International Collaboration and the Joint Strike Fighter

Capturing Fortress Europe: International Collaboration and the Joint Strike Fighter

Capturing Fortress Europe: International Collaboration and the Joint Strike Fighter

Capturing Fortress Europe: International Collaboration and the Joint Strike Fighter

Mathcad as a standard design package for F-35 Joint Strike Fighter project

Mathcad as a standard design package for F-35 Joint Strike Fighter project

Joint Strike Fighter Integrated Subsystems Technology, A Demonstration for Industry, by Industry

The Joint Strike Fighter (JSF) Integrated Subsystems Technology Demonstration Program was a highly successful industry-wide five-year program in which normally competitive JSF weapon system contractors and suppliers worked together with competitors to accomplish technology maturation and mitigate technological risks of a revolutionary subsystem concept for tactical aircraft that integrates the subsystems and utility functions thereby reducing the associated major equipment groups from 13 to 5. As a result of this integration, the volume, weight, and costs allocated to these subsystems are significantly reduced without sacrificing vehicle performance and safety. Major and minor management and execution methods used to focus, solidify, and maintain this industry team over the five-year program are outlined.

Joint Strike Fighter Integrated Subsystems Technology, A Demonstration for Industry, by Industry

Joint Strike Fighter Integrated Subsystems Technology, A Demonstration for Industry, by Industry

Open systems avionics architectures considerations

Australia has announced that it will join the System Development and Demonstration phase of the F-35 Joint Strike Fighter programme. The JSF boasts an advanced integrated avionics architecture that will utilise commercial-off-the-shelf (COTS) hardware and software, and embrace an Open Systems Architecture. If Australia should procure the JSF, it will move from a base experience in second generation avionics architectures to a fourth-generation system. It will also move from supporting and accepting MIL-SPEC unique avionics to COTS-based computer equipment. Further, the mid-life or block upgrade mindset for increasing capability may be transformed with the introduction of COTS equipment to a constant or evolutionary upgrade path that will have ramifications for logistics, engineering certification, and acceptance into operational service.

The effects of streamlined operations on the perceived quality success criteria at Lockheed Martin Aeronautics – Fort Worth

The reduction in the US defense budget has resulted in reduced employment at Lockheed Martin Aeronautics – Fort Worth site by more 20,000 employees within the last decade. The company pursued a strategy to increase productivity and quality with the reduced work force while maintaining not only the public trust, but also the trust of its employees. Maintaining employee trust is directly linked to employees’ belief in the security of their employment. While the recently won Joint Strike Fighter contract will cause the need to expand, today’s competitive aerospace environment implies the need to maintain those strategies that resulted in that contract. Due to the requirement for high employee involvement, the company embraced a strategy to develop an environment that fostered a committed and highly motivated workforce. The University of North Texas, Center for Quality and Productivity assisted by completing a quality success factors survey to assess the employees’ perceptions of quality. As the questionnaire was analyzed, it was discovered that the cohesive work force was homogeneous in its strong identification with the quality goals of the company.

Lockheed Martin Chairman and CEO Vance Coffman on achieving mission success

Executive OverviewLockheed Martin Corporation was formed in 1995 with the merger of two of the world's premier technology companies, Lockheed Corporation and Martin Marietta Corporation. In 1996 Lockheed Martin completed its strategic combination with the defense electronics and systems integration businesses of Loral. Lockheed Martin currently employs about 125,000 people worldwide and is principally engaged in the research, design, development, manufacture, and integration of advanced technology systems, products, and services. Its operating units are organized into broad business areas, including aeronautics (e.g., tactical aircraft, airlift, and aeronautical research and development), space systems (e.g., space launch, commercial satellites, government satellites, and strategic missiles), systems integration (e.g., missiles and fire control, naval systems, platform integration, and C4I), and technology services (e.g., federal services, energy programs, commercial IT, and aeronautical services). In 2001 Lockheed Martin reported total sales of $24 billion in addition to a record sales backlog of more than $71 billion. Dr. Vance D. Coffman, Lockheed Martin Corporation's chief executive officer and chairman of its board of directors, was elected to his current position in 1997 after serving as the corporation's president and chief operating officer and, earlier, as executive vice president and chief operating officer. Previously, he served as president and chief operating officer of Lockheed Martin's Space and Strategic Missiles Sector. Prior to the merger of Lockheed and Martin Marietta in 1995, he served as executive vice president of Lockheed Corporation. Before that, he was president of the Space Systems Division of Lockheed Missiles & Space Company and a vice president of the corporation. Born in Kinross, Iowa, Dr. Coffman holds a bachelor of science degree in aerospace engineering from Iowa State University and master's and doctoral degrees in aeronautics and astronautics from Stanford University. Coffman joined Lockheed's Space Systems Division in 1967 as a guidance and control systems analyst. Alter leading the development of several major space programs and large ground data processing systems, he was appointed a vice president in 1985. division vice president and assistant general manager in 1987, and president of the Space Systems Division in 1988. While in that position, he was responsible for the Hubble Space Telescope, the M1LSTAR satellite communications program, and the Follow-on Early Warning System (now called the Space Based Infrared System). As CEO and chairman of the board, Coffman presided over Lockheed Martin's financial turnaround during a period of worldwide defense and aerospace industry consolidation (as two dozen companies shrunk to four or five) as well as the successful Joint Strike Fighter (JSF) bid that holds the potential for $300 billion in future sales. Dr. Coffman currently serves on the board of directors at Bristol-Myers Squibb Company and 3M. He is also a member of the National Academy of Engineering (NAE), the American Institute of Aeronautics & Astronautics (in which he became a Fellow in 1996), the American Astronautical Society (in which he became a Fellow in 1991), the American Defense Preparedness Association/National Security Industrial Association, and the Security Affairs Support Association.

TRW to provide weapons bay door drive system on Joint Strike Fighter

TRW to provide weapons bay door drive system on Joint Strike Fighter

PTC solutions are critical in Joint Strike Fighter Program

PTC solutions are critical in Joint Strike Fighter Program