Abstract: A fuselage comprising a skin assembly including an outer, laminate skin bonded to an inner, aluminum doubler. The fuselage also includes a support structure comprising a plurality of longitudinal stringer members and a plurality of annular frame members that are attached to, and cooperate to support, the skin assembly. The aluminum doubler provides additional structural support for the fuselage, and in particular, for the outer laminate skin of the skin assembly. The additional structural strength added by the aluminum doubler allows the use of an improved range of fasteners, such as knife-edge, countersink rivets and further allows the use of the laminate layer even in areas with a large number of cutouts, such as the window track of the fuselage. The members of the support structure may interconnected via a plurality of integral flanges, which, when combined with the skin, provide improved structural strength for the entire fuselage.

Abstract: A fixed wing rotorcraft uses differential thrust between wing mounted propellers to provide counter torque when the rotor is being powered by a power source. The rotorcraft is comprised of a fuselage to which fixed wings are attached. A rotor is attached on an upper side of the fuselage and provides lift at low speeds while the wings provide a majority of the lift at high speeds. When at high speeds the rotor may be slowed to reduce advancing tip speed and retreating blade stall. Forward thrust and counter torque is provided by propellers mounted on either side of the fuselage or even on the wings.

Abstract: An apparatus for riveting shell components to form a barrel-shaped structure such as an aircraft fuselage includes an outer part and an inner part that operate coordinated with each other under computer control. The outer apparatus part includes a riveting machine system movably carried on an annular machine guide that is supported on a stand that is movable in a length-wise X-direction. The inner apparatus part includes a multi-axis riveting robot mounted on a mounting frame that is movable along the X-direction. Instead of moving the inner and outer apparatus parts in the X-direction, it is alternatively possible to move the fuselage while keeping the apparatus parts stationary. A computer control unit provides control signals to achieve a coordinated and concurrent positioning of the inner and outer apparatus parts, and to carry out a coordinated sequence of riveting steps. Rivets can be automatically fastened even at difficult to access locations, while avoiding structural obstacles inside the aircraft fuselage. The apparatus parts are supported independently of the fuselage on the floor of the assembly hall.

Abstract: An aircraft ( 10 ) is disclosed that comprises a fuselage ( 12 ) with first and second wings ( 14 ) non-rotatably secured to and extending from sides of the fuselage ( 12 ). Inner and outer tracks are secured to and encircle the fuselage ( 12 ), and airfoils ( 20 ) are operably secured between the inner and outer tracks. Means are provided for rotating the airfoils ( 20 ). The means for rotating the airfoils may be comprised of first and second drive coils ( 40 ), and first and second alternators ( 80 ) may be operably coupled to the first and second drive coils ( 40 ), respectively, to provide redundant power supplies. Permanent magnets ( 44 ) in the rotor hub may be arranged in a Halbach array or may be arranged to provide a series of alternating, opposite magnetic poles. Separate drive and suspension coils ( 38 ) may be provided in the stator ( 16 ). The concept may find further application in a lift fan or tail section of conventional aircraft. In that regard, a lift fan or tail section may be provided in which a stator magnetically levitates a lift fan rotor or tail rotor. The stator may include suspension coils ( 38 ) and drive coils ( 40 ) to eliminate the need for a drive shaft and gears to power the lift fan rotor or tail rotor.

Abstract: A structural and aeroelastic model for wing sizing and weight calculation of a strut-braced wing is described. The wing weight is calculated using a newly developed analysis accounting for the special nature of strut-braced wings. A specially developed aeroelastic model enables one to consider wing flexibility and spanwise redistribution of the aerodynamic loads during in-flight maneuvers. The structural model uses a hexagonal wing-box featuring skin panels, stringers, and spar caps, whereas the aerodynamics part employs a linearized transonic vortex lattice method. Thus, the wing weight may be calculated from the rigid or flexible wing spanload. The calculations reveal the significant influence of the strut on the bending material weight of the wing. The strut enables one to design a wing featuring thin airfoils without weight penalty. It also influences the spanwise redistribution of the aerodynamic loads and the resulting deformations. Increased weight savings are possible by iterative resizing of the wing structure using the actual design loads. As an advantage over the cantilever wing, the twist moment caused by the strut force results in increased load alleviation, leading to further structural weight savings.

Abstract: The present paper has documented the historical relationships between various classes of all lifting vehicles, which includes the flying wing, all wing, tailless, lifting body, and lifting fuselage. The diversity in vehicle focus was to ensure that all vehicle types that map have contributed to or been influenced by the development of the classical flying wing concept was investigated. The paper has provided context and perspective for present and future aircraft design studies that may employ the all lifting vehicle concept. The paper also demonstrated the benefit of developing an understanding of the past in order to obtain the required knowledge to create future concepts with significantly improved aerodynamic performance.

Abstract: A vertical take-off and landing vehicle that employs a thrust assembly, a fuselage, and an intermediate rotation decoupling interface assembly for rotationally decoupling the thrust assembly from the fuselage. The thrust assembly forms a single combined thrust force about the fuselage in order to form a more stable vehicle during flight.

Abstract: The Boeing Company demonstrated the application of stitched/resin infused (S/RFI) composite materials on commercial transport aircraft primary wing structures under the Advanced Subsonic technology (AST) Composite Wing contract, NAS1-20546. This report describes a weight trade study utilizing a wing torque box design applicable to a 220-passenger commercial aircraft and was used to verify the weight savings a S/RFI structure would offer compared to an identical aluminum wing box design. This trade study was performed in the AST Composite Wing program, and the overall weight savings are reported. Previous program work involved the design of a S/RFI-baseline wing box structural test component and its associated testing hardware. This detail structural design effort which is known as the "semi-span" in this report, was completed under a previous NASA contract (NAS1-18862). The full-scale wing design was based on a configuration for a MD-90-40X airplane, and the objective of this structural test component was to demonstrate the maturity of the S/RFI technology through the evaluation of a full-scale wing box/fuselage section structural test. However, scope reductions of the AST Composite Wing Program prevented the fabrication and evaluation of this wing box structure. Results obtained from the weight trade study, the full-scale test component design effort, fabrication, design development testing, and full-scale testing of the semi-span wing box are reported.

Abstract: A number of bird species swim underwater by wing propulsion. Both among and within species, thrust generated during the recovery phase (upstroke) varies from almost none to more than during the power phase (downstroke). More uneven thrust and unsteady speed may increase swimming costs because of greater inertial work to accelerate the body fuselage (head and trunk), especially when buoyant resistance is high during descent. I investigated these effects by varying relative fuselage speed during upstroke vs. downstroke in a model for wing-propelled murres which descend at relatively constant mean speed. As buoyant resistance declined with depth, the model varied stroke frequency and glide duration to maintain constant mean descent speed, stroke duration, and work per stroke. When mean fuselage speed during the upstroke was only 18% of that during the downstroke, stroke frequency was constant with no gliding, so that power output was unchanged throughout descent. When mean upstroke speed of the fuselage was raised to 40% and 73% of mean downstroke speed, stroke frequency declined and gliding increased, so that power output decreased rapidly with increasing depth. Greater inertial work with more unequal fuselage speeds was a minor contributor to differences in swimming costs. Instead, lower speeds during upstrokes required higher speeds during downstrokes to maintain the same mean speed, resulting in nonlinear increases in drag at greater fuselage speeds during the power phase. When fuselage speed was relatively higher during upstrokes, lower net drag at the same mean speed increased the ability to glide between strokes, thereby decreasing the cost of swimming.

Abstract: A structural panel component, such as an aircraft fuselage shell component, includes a single integral part having longitudinal and crosswise stiffening elements integrally arranged on a skin sheet. This integral component has been formed by a high speed milling chip removal process applied to a solid plate-shaped semi-finished starting material. The skin sheet has areas of differing thicknesses, and the height, thickness, and spacing of the stiffening elements varies as needed, depending on the local loading conditions that will prevail on the finished structural component. The configuration of the component can be optimized to minimize the weight while satisfying all load strength requirements. The manufacturing method is very simple and economical.

Abstract: A composite fuselage concept for light aircraft has been developed to provide improved crashworthiness. The fuselage consists of a relatively rigid upper section, or passenger cabin, including a stiff structural e oor and a frangible lower section that encloses the crash energy management structure. The crashworthy performance of the fuselage concept was evaluated through impact testing of a one-e fth-scale model fuselage section. The impact design requirement for the scale model fuselage is to achieve a 125- g average e oor-level acceleration for a 31ft/s vertical impact onto a rigid surface. The energy absorption behavior of two different sube oor cone gurations was determined through quasi-static crushing tests. For the dynamic evaluation, each sube oor cone guration was incorporated into a one-e fth-scale model fuselage section, which was dropped from a height of 15 ft to achieve a 31-ft/s vertical velocity at impact. The experimental data demonstrate that the fuselage section with a foam-block sube oor cone guration satise ed the impact design requirement. A second drop test was performed to evaluate the energy absorption performanceofthefuselageconceptfor an off-axis impactcondition. The experimental data are correlated with analytical predictions from a e nite element model developed using the nonlinear, explicit transient dynamic code MSC/DYTRAN.

Abstract: Computations of lift and drag polars for a transport aircraft wing/fuselage high-lift cone guration using the MEGAFLOWcodesystemarecarriedoutandcomparedtowind-tunnelexperiments.Themainemphasisislaidon acomparisonoftheblock-structuredandtheunstructuredcodemodulesforsuchtypeofapplication.FortheblockstructuredFLOWercodeincombinationwith a k‐! turbulencemodel,thenumericalresultsarein good agreement with the available experimental data in the linear CL range. Beyond 15-deg incidence, a strong separation near the e ap cut-out is simulated, leading to an underprediction of total lift near CL; max compared to the experimental data. In contrast to this, the results of the unstructured TAU code utilizing the Spalart ‐Allmaras turbulence model are characterized by a nearly constant lift overestimation up to maximum lift without the aforementioned separation tendency at moderate incidences. The lift overprediction in the unstructured results is attributed to the main wing and the slat upperside suction peaks, which are higher resolved by the unstructured grid. Neither code reproduces the lift breakdown beyond CL; max according to the experiments. The use of preconditioning in conjunction with theFLOWercodeshowsonly minorimprovement of theaccuracy,but considerabledeterioration of the convergence properties, requiring improvements for routine use. Further studies will focus on the ine uence of geometry simplie cations at the wing root in the theoretical models and its impact on the experimental evidence.

Abstract: This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Traveling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing's top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five segments of the wing has one or more motors and photovoltaic arrays, and produces its own lift independent of the other segments, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft includes hinges and actuators capable of providing an adjustable dihedral for the wing. The actuators can be motors or control surfaces. Alternately, the actuators can be movable masses within the wing, which may be capable of deforming the wing to alter the aerodynamics of the wing, and thereby actuate the hinges. Because of wing dihedral, the aircraft includes motors both above and below the center of drag, and the aircraft uses differential thrust to control aircraft pitch. The aircraft has a wide variety of applications, which include serving as a long term high altitude platform that serves to link a ground station using radio wave signals and a satellite using optical signals.

Abstract: Within the framework of Brite-Euram programme CRASURV "Commercial Aircraft -Design for Crash Survivability", technology is being developed for the design of composite air frames with respect to crashworthiness The ultimate goal of the project is to develop computer codes for the simulation of the crash behaviour of composite fuselage structures A significant part of the project consists of the design, fabrication and drop-testing of two representative composite fuselage sections, to generate the experimental data needed for the validation of the new code developments The present paper gives an overview of the development, test and numerical analysis of one of the fuselage sections, a one-bay section representative of a commuter aircraft like the ATR-42/72 The fuselage section consists of the sub-floor structure, which is the major area that will be crushed during a potentially survivable crash

Abstract: The F/A-18E/F is the U.S. Navy's premier strike fighter aircraft, manufactured by the Boeing Company. The F/A-18E/F aircraft, while maintaining a high degree of commonality with the F/A-18C/D aircraft, has a lengthened fuselage, larger wing and control surfaces, strengthened landing gear, an improved propulsion system including a growth version of the General Electric F404 engine designated the F414-GE-400, and larger high performance inlets. This paper concentrates on the development, test, and evaluation of the F/A-18E/F Automatic Carrier Landing System (ACLS) up to and including the Third Sea Trials, upon which the aircraft was initially qualified for Mode I, totally automatic, approaches and landings to the aircraft carrier. The paper briefly describes the key components of the F/A-18E/F's ACLS, including cockpit displays and controls, antennas, autothrottles and flight control implementation, and interface with the shipboard AN/SPN-46(V) ACLS. Test procedures and methodology are presented as well as test results and interpretation. Finally, lessons learned are presented and recommendations are made for future aircraft ACLS developmental test and evaluation efforts.

Abstract: An extremely large aircraft which is suitable for overseas cargo transport and which includes a fuselage defining a central storage cavity, a wing assembly defining a pair of wing storage cavities, an altitude control system, and a plurality of independently steerable landing gear units. The central storage cavity has a length, height and width of at least 100 feet, at least 16 feet and at least 24 feet, respectively. The wing assembly has a wingspan of at least 300 feet and is configured with a moderate aspect ratio to permit both ground-effect and high altitude operation. The altitude control system controls the aircraft in ground effect such that the aircraft is maintained at about a predetermined altitude. The landing gear units are coupled to the fuselage and are arranged in at least two discrete columns and at least ten discrete rows. The central storage cavity and the wing storage cavities are configured to receive cargo including intermodal re-usable cargo containers.

Abstract: An aircraft including a fuselage, a compound tilting wing (CTW) and aircraft engines mounted on the aircraft. The CTW includes a leading edge wing portion and a tilting main wing portion. The leading edge wing portion and the tilting main wing portion each include a leading edge, a trailing edge, a chord, a lower surface and an upper surface. The tilting main wing portion is pivotally mounted on the fuselage for rotation from a cruise flight position to various low flight speed positions. In the cruise flight position, the tilting main wing portion fits conformably with the leading edge wing portion forming an aerodynamically single wing. In one embodiment, two aircraft engines are mounted on a fixed leading edge wing portion and two aircraft engines are mounted on the tilting main wing portion.

Abstract: A system and method for radiographic inspection of aircraft fuselages includes a radiation source preferably located inside of the fuselage and a radiation detector preferably located outside of the fuselage. A source positioning system is provided for moving the radiation source longitudinally with respect to the fuselage, and a detector positioning system is provided for positioning the radiation detector in longitudinal alignment with the radiation source. The detector positioning system also moves the radiation detector circumferentially with respect to the fuselage. In operation, the radiation detector is moved over the fuselage in a circumferential direction while the radiation source illuminates an adjacent region of the fuselage with radiation.

Abstract: The focus of this paper is to describe a crash simulation of a 30-ft/s vertical drop test of a Boeing 737 (B737) fuselage section. The drop test of the 10-ft. long fuselage section of a B737 aircraft was conducted in November of 2000 at the FAA Technical Center in Atlantic City, NJ. The fuselage section was outfitted with two different commercial overhead stowage bins. In addition, 3,229-lbs. of luggage were packed in the cargo hold to represent a maximum take-off weight condition. The main objective of the test was to evaluate the response and failure modes of the overhead stowage bins in a narrow-body transport fuselage section when subjected to a severe, but survivable, impact. A secondary objective of the test was to generate experimental data for correlation with the crash simulation. A full-scale 3-dimensional finite element model of the fuselage section was developed and a crash simulation was conducted using the explicit, nonlinear transient dynamic code, MSC.Dytran. Pre-test predictions of the fuselage and overhead bin responses were generated for correlation with the drop test data. A description of the finite element model and an assessment of the analytical/experimental correlation are presented. In addition, suggestions for modifications to the model to improve correlation are proposed.

Abstract: A composite fuselage concept for light aircraft and rotorcraft has been developed to provide improved crash protection. The fuselage consists of a relatively rigid upper section, or passenger cabin, including a stiff structural floor and a frangible lower section which encloses the crash energy management structure. A 60-in diameter full-scale fuselage section was manufactured using a composite sandwich construction. Vertical drop tests were conducted at both 0°- and 15°-roll impact attitudes to evaluate the crashworthy features of the fuselage design. The experimental data are correlated with predictions from a finite element model developed using the non-linear, explicit transient dynamic code, MSC.Dytran.

Abstract: The probability of detection (POD) of hidden fatigue defects in riveted multilayer joints, e.g. aircraft fuselage, can be improved by using sophisticated eddy-current systems which provide more information than conventional NDE equipment. In order to collect this information, sensor arrays or multi-frequency excitation schemes can be used. We have performed simulations and measurements with an eddy current NDE system based on a SQUID magnetometer. To distinguish between signals caused by material defects and those caused by structures in the sample, such as bolts or rivets, a high signal-to-noise ratio is required. Our system provides a large analog dynamic range of more than 140 dB//spl radic/Hz in unshielded environment, a digital dynamics of the ADC of more than 25 bit (>150 dB) and multiple frequency excitation. A large number of stacked aluminum samples resembling aircraft fuselage were measured, containing titanium rivets and hidden defects in different depths in order to obtain sufficient statistical information for classification of the defect geometry. We report on flaw reconstruction using adapted feature extraction and neural network techniques.

Abstract: As part of the full scale fuel fire experimental program, a series of JP-8 pool fire experiments with a large cylindrical calorimeter (3.66 m diameter), representing a C-141 aircraft fuselage, at the lee end of the fuel pool were performed at Naval Air Warfare Center, Weapons Division (NAWCWPNS). The series was designed to support Weapon System Safety Assessment (WSSA) needs by addressing the case of a transport aircraft subjected to a large fuel fire. The data collected from this mock series will allow for characterization of the fire environment via a survivable test fixture. This characterization will provide important background information for a future test series utilizing the same fuel pool with an actual C-141 aircraft in place of the cylindrical calorimeter.