Abstract: A compound rotorcraft including a rotary wing aircraft having a fuselage and at least one rotor and a fixed-wing aircraft coupled to the rotary wing aircraft, wherein the rotary wing aircraft can fly on the rotor or the fixed-wing aircraft, and wherein the fixed-wing aircraft is detachable from the rotary wing aircraft to fly independently.

Abstract: A vertical take-off and landing (VTOL) aircraft according to an aspect of the present invention comprises a fuselage, an empennage having an all-moving horizontal stabilizer located at a tail end of the fuselage, a wing having the fuselage positioned approximately halfway between the distal ends of the wing, wherein the wing is configured to transform between a substantially straight wing configuration and a canted wing configuration using a canted hinge located on each side of the fuselage. The VTOL aircraft may further includes one or more retractable pogo supports, wherein a retractable pogo support is configured to deploy from each of the wing's distal ends.

Abstract: The European aircraft industry has strong interest in novel structural concepts for future aircraft fuselage with lower fabrication costs and high performance. A critical safety issue for the design of aircraft structure is vulnerability and damage tolerance due to foreign object impact. This paper focuses on the improvement of modelling techniques for foldcore sandwich structures with composite skins under low velocity impact. A new modelling approach for the foldcore cell wall material – aramid paper – is presented, which considers the aramid papers inhomogeneous nature in the thickness direction. In combination with in-ply continuum damage mechanics and a cohesive delamination interface for the modelling of the composite surface skin the proposed modelling approach is used to reproduce drop tower impact tests performed at various impact velocities. Results and interpretation of the numerical and experimental work are presented. The strengths and weaknesses of the presented modelling approach are discussed and evaluated.

Abstract: A tiltrotor aircraft includes a fuselage; a wing member having a first rib, a second rib, a first spar, second spar; and an upper wing skin; an engine disposed at a fixed location relative to the wing member; and a proprotor having a spindle gearbox, rotor mast, and a plurality of rotor blades drivable in rotation about the rotor mast, the spindle gearbox being rotatable about a conversion axis. The spindle gearbox is located above the upper wing skin of the wing member.

Abstract: Model scale tests of modern ‘open rotor’ propulsor concepts that have potential for significant fuel burn reduction for aircraft applications were completed at NASA Glenn Research Center. The recent test campaign was a collaboration between NASA, FAA, and General Electric (GE). GE was the primary industrial partner, but other organisations were involved such as Boeing and Airbus who provided additional hardware for fuselage simulations. The open rotor is a modern version of the UnDucted Fan (UDF®) that was flight tested in the late 1980s through a partnership between NASA and GE. The UDF® was memorable for its scimitar shaped propeller blades and its unique noise signature. Design methods of the time were not able to optimise for both high aerodynamic efficiency and low noise simultaneously. Contemporary CFD/CAA based design methods can produce open rotor blade designs that maintain efficiency with acceptable acoustic signatures. Tests of two generations of new open rotor designs were conducted in the 9’ × 15’ Low Speed Wind Tunnel and the 8’ × 6’ Supersonic Wind Tunnel starting in late 2009 and completed in early 2012. Aerodynamic performance and acoustic data were obtained for take-off, approach and cruise conditions in isolated and semi-installed configurations. Additional detailed flow diagnostic measurements and acoustic measurements, including canonical shielding configurations, were obtained by NASA. NASA and GE conducted joint systems analysis to evaluate the performance of the new blade designs on a Boeing 737 class aircraft. The program demonstrated a 2-3% improvement in overall net efficiency relative to the best efficiency designs of the 1980s while nominally achieving 15-17 EPNdB noise margin to Chapter 4 (at a Technology Readiness Level of 5) for a notional aircraft system defined by NASA.

Abstract: Boundary Layer Ingestion (BLI) is currently being researched as a potential method to improve efficiency and decrease emissions for the next generation of commercial aircraft. While re-energizing the boundary layer formed over the fuselage of an aircraft has many system level benefits, ingesting the low velocity boundary layer flow through a serpentine inlet into a turbofan engine adversely affects the performance of the engine. This work reports an experimental investigation of the effects of a BLI-type distortion on a turbofan engine’s performance. A modified JT15D-1 turbofan engine was used in this study. Inlet flow distortion was created by a layered wire mesh distortion screen designed to create a total pressure distortion profile at the aerodynamic interface plane (AIP) similar to NASA’s Inlet A boundary layer ingesting inlet flow profile. Results of this investigation showed a 15.5% decrease in stream thrust and a 14% increase in TSFC in the presence of BLI-type distortion. The presence of the distortion screen resulted in a 24% increase in mass-averaged entropy production along the entire fan flow path compared to the non-distorted test.Copyright © 2014 by ASME

Abstract: A method of installing a fixture, such as a bracket, in a fuselage structure of an aircraft includes the steps of: providing or generating a three-dimensional digital model of the fixture; arranging a head of an additive manufacturing apparatus in the fuselage structure; and forming the fixture in situ in the fuselage structure with the head of the additive manufacturing apparatus based upon the digital model of the fixture. The fixture is installed in the fuselage structure by bonding or fusing the fixture to the fuselage structure as the fixture is formed. A fixture, such as a bracket, which is generated in situ in a fuselage structure of an aircraft based upon a three-dimensional digital model, wherein the fixture is bonded or fused to the fuselage structure as the fixture is formed.

Abstract: This investigation is performed to develop a methodology for the variation analysis and prediction of aircraft fuselage panel riveting assembly. Firstly, according to the manufacturing process of the part of the aircraft fuselage panel, the method of influence coefficient (MIC) based on key feature deviation is proposed. Secondly, the mechanism of component deformation in riveting process is expounded, and the method to approximately compute the global distortion, caused by rivet deformation, of the fuselage panel is presented. The proposed method is illustrated through a case study on the riveting assembly process of a sidewall panel, the local plastic deformation near the riveting holes is ignored but the computing resources are saved, the complex and time-consuming computation are avoided. The reasonableness of the proposed method is verified by the measurement data of the prototypes.

Abstract: A method and apparatus for performing an assembly operation (664). A tool (629) may be macro-positioned (661) relative to an exterior (234) of a fuselage assembly (114). The tool (629) may be micro-positioned (663) relative to a particular location (662) on the exterior (234) of the fuselage assembly (114). An assembly operation (664) may be performed at the particular location (662) on the panel (216) using the tool (629).

Abstract: The results of an experimental study on the effects of engine placement and vertical tail configuration on shielding of exhaust broadband noise radiation are presented. This study is part of the high fidelity aeroacoustic test of a 5.8% scale Hybrid Wing Body (HWB) aircraft configuration performed in the 14- by 22-Foot Subsonic Tunnel at NASA Langley Research Center. Broadband Engine Noise Simulators (BENS) were used to determine insertion loss due to shielding by the HWB airframe of the broadband component of turbomachinery noise for different airframe configurations and flight conditions. Acoustics data were obtained from flyover and sideline microphones traversed to predefined streamwise stations. Noise measurements performed for different engine locations clearly show the noise benefit associated with positioning the engine nacelles further upstream on the HWB centerbody. Positioning the engine exhaust 2.5 nozzle diameters upstream (compared to 0.5 nozzle diameters downstream) of the HWB trailing edge was found of particular benefit in this study. Analysis of the shielding performance obtained with and without tunnel flow show that the effectiveness of the fuselage shielding of the exhaust noise, although still significant, is greatly reduced by the presence of the free stream flow compared to static conditions. This loss of shielding is due to the turbulence in the model near-wake/boundary layer flow. A comparison of shielding obtained with alternate vertical tail configurations shows limited differences in level; nevertheless, overall trends regarding the effect of cant angle and vertical location are revealed. Finally, it is shown that the vertical tails provide a clear shielding benefit towards the sideline while causing a slight increase in noise below the aircraft.

Abstract: . Because of the high travel speed, the complex flow dynamics around an aircraft, and the complex dependency of the fluid dynamics on numerous airborne parameters, it is quite difficult to obtain accurate pressure values at a specific instrument location of an aircraft's fuselage. Complex simulations using computational fluid dynamics (CFD) models can in theory computationally "transfer" pressure values from one location to another. However, for long flight patterns, this process is inconvenient and cumbersome. Furthermore, these CFD transfer models require a local experimental validation, which is rarely available. In this paper, we describe an integrated approach for a spectroscopic, calibration-free, in-flight pressure determination in an open-path White cell on an aircraft fuselage using ambient, atmospheric water vapour as the "sensor species". The presented measurements are realised with the HAI (Hygrometer for Atmospheric Investigations) instrument, built for multiphase water detection via calibration-free TDLAS (tunable diode laser absorption spectroscopy). The pressure determination is based on raw data used for H2O concentration measurement, but with a different post-flight evaluation method, and can therefore be conducted at deferred time intervals on any desired flight track. The spectroscopic pressure is compared in-flight with the static ambient pressure of the aircraft avionic system and a micro-mechanical pressure sensor, located next to the open-path cell, over a pressure range from 150 to 800 hPa, and a water vapour concentration range of more than 3 orders of magnitude. The correlation between the micro-mechanical pressure sensor measurements and the spectroscopic pressure measurements shows an average deviation from linearity of only 0.14% and a small offset of 9.5 hPa. For the spectroscopic pressure evaluation we derive measurement uncertainties under laboratory conditions of 3.2 and 5.1% during in-flight operation on the HALO airplane. Under certain flight conditions we quantified, for the first time, stalling-induced, dynamic pressure deviations of up to 30% (at 200 hPa) between the avionic sensor and the optical and mechanical pressure sensors integrated in HAI. Such severe local pressure deviations from the typically used avionic pressure are important to take into account for other airborne sensors employed on such fast flying platforms as the HALO aircraft.

Abstract: An aircraft with an electric propulsion arrangement which includes a fuselage, a wing system attached to the fuselage, and a tail unit attached to a rear part of the fuselage. The electric propulsion arrangement is arranged on each side of the fuselage, an electrical energy generator and electricity storage and supply devices are arranged substantially along a longitudinal axis of symmetry of the fuselage. The aircraft thus incorporates a hybrid motorization.

Abstract: however were never introduced previously. The final Chapter 11 of the book introduces an adaptive controller based on fuzzy logic, but again the description of this methodology is very brief and obliges the average reader to go elsewhere, leaving the second part of this chapter as a display of some numerical results of a specific application on which the authors have worked in the past. As final remarks, the authors state in the introduction that the text shall be used by practicing engineers and that other texts provide a deeper theoretical background. Certainly the book has a strong example-based approach: the authors mention the concept of ‘learn by practicing’, but my feeling is that the numerical examples shown are not sufficient for the inexperienced reader, because mainly of lack of generality and discussion. Also, due to the general lack of rigour, example-based approach and variable level of depth, I discourage the use of this book as a textbook or as a first book in orbital dynamics or control. Instead, it can provide an overview of possible space applications to the already experienced engineer. Regarding the ‘digital control perspective’, there are so many aspects of digital control, and in particular design by emulation, that are interesting, but are not covered with enough detail in this book, if at all: introduction of holds, pole placement techniques, stability of discrete equivalents and others. Due to the absence of discussion, the fact that the discrete version of the controllers are used throughout the book does not make a difference to what would have been a discussion with a continuous-time approach. The book is rich in good references (including recent journal papers) and if the reader is ready to read further, the book can be used as a starting point on the subject. Dr Matteo Ceriotti CEng, MIMechE Lecturer in Space Systems Engineering University of Glasgow Riveted Lap Joints in Aircraft Fuselage: Design, Analysis and Properties

Abstract: In this paper, a biplane-wing/twin-body-fuselage configuration is discussed for advanced supersonic transport The supersonic-biplane-wing concept has been proposed by Kusunose et al (“Supersonic Biplane—A Review,” Progress in Aerospace Sciences, Vol 47, No 1, 2011, pp 53–87), and a remarkable drag reduction in supersonic flow conditions has been demonstrated in the literatures Motivated by the wave reduction effect of the supersonic biplane airfoils, a twin-body-fuselage concept has also been proposed by the present authors Wave-drag reduction was achieved by an optimal twin-body-fuselage configuration In this research, therefore, the biplane-wing concept and the twin-body-fuselage concept are merged to propose an innovative supersonic transport configuration The wave-drag characteristics, as well as the wave-drag reduction, are illustrated by inviscid computational fluid dynamics computations at the design Mach number of 17 The inviscid (wave) drag of the proposed configuration is much smaller

Abstract: One approach toward achieving NASA's aggressive N+2 noise goal of 42 EPNdB cumulative margin below Stage 4 is through the use of novel vehicle configurations like the hybrid wing body. Jet noise measurements from a hybrid wing body acoustic test in the NASA Langley 14- by 22-Foot Subsonic Tunnel are described. Two dual-stream, heated Compact Jet Engine Simulator units are mounted underneath the inverted hybrid wing body model on a traversable support to permit measurement of varying levels of shielding provided by the fuselage. Both an axisymmetric and low noise chevron nozzle set are investigated in the context of shielding. The unshielded chevron nozzle set shows 1–2 dB of source noise reduction (relative to the unshielded axisymmetric nozzle set) with some penalties at higher frequencies. Shielding of the axisymmetric nozzles shows up to 6.5 dB of reduction at high frequency. The combination of shielding and low noise chevrons shows benefits beyond the expected additive benefits of the two, up to 10 dB, due to the effective migration of the jet source peak noise location upstream for increased shielding effectiveness. Jet noise source maps from phased array results processed with the deconvolution approach for the mapping of acoustic sources algorithm reinforce these observations.

Abstract: Aircraft have evolved into extremely complex machines that require adapted tools to allow efficient design process. A performance formulation based on an exergy balance is under development at ONERA for assessing future aircraft configurations. A control volume analysis is performed to relate the exergy supplied by the propulsion system, its partial destruction within the control volume and the aircraft mechanical equilibrium. The formulation does not rely on the expression of thrust and drag and is therefore especially suitable for the performance evaluation of blended-wing bodies with boundary layer ingestion. A first step towards such applications is the investigation of a more academic configuration consisting in the ingestion of the complete wake of a simplified fuselage. Investigation is made via 3D RANS computations and it is shown that the benefit is due to lower levels of exergy destruction in the wake/jet of the BLI configuration.

Abstract: The fuselage of the Buccaneer was designed using Whitcomb's area rule technique, which had the effort of reducing drag while travelling at high subsonic and transonic speeds, and gave rise to the characteristic curvy "Coke bottle" shape of the fuselage. The majority of the airframe and fuselage was machined from solid casting to give great strength to endure the stress of low level operations. Considerable effort went into ensuring that metal fatigue would not be a limiting factor of the Buccaneer's operational life even under the formidable conditions imposed of continuous low level flight. A large split air brake was built into the tail cone of the aircraft. The hydraulically operated air brake formed two leaves that could be opened into the air stream to quickly decelerate the aircraft. The style of air brake chosen by Blackburn was highly effective in the dive-attack profile that the Buccaneer was intended to perform, as well as effectively balancing out induced drag from operating the BLC system. It featured a variable incidence tail-plane that could be trimmed to suit the particular requirements of low-speed handling or high-speed flight; the tail-plane had to be high mounted due to the positioning and functionality of the Buccaneer's air brake. The wing design of the Buccaneer was a compromise between two requirements: a low aspect ratio for gust response and high aspect ratio to give good range performance. The relatively small wing was suited to high-speed flight at low altitude; however, a small wing did not generate sufficient lift that was essential for carrier operations. Therefore, BLC (Boundary Layer Control) was used upon both the wing and horizontal stabilizer, having the effect of energising and smoothing the boundary layer airflow, which significantly reduced airflow separation at the back of the wing, and therefore decreased stall speed, and increased effectiveness of trailing edge control surfaces including flaps and ailerons. For use on aircraft carriers the complete nose and tail sections could be swivelled 180°. Reason for this was that the aircraft had to fit in the aircraft carrier's lift.

Abstract: This paper studies the crashworthiness characteristics of a fuselage section and its improvement. A full-scale three-dimensional finite element model of the fuselage section is developed using a nonlinear finite element code, PAM-CRASH. The simulation is implemented to determine the structural deformation and impact response in terms of peak loads and acceleration peaks at the floor-level, deformation mode, energy absorption, and structural integrity, and then to assess the crashworthiness of the fuselage section. By partitioning the total energy dissipated, it is shown that the frames and the supports of the cargo floor play important roles in the process of energy dissipation. Based on the results, an effective approach to improve the crashworthiness of the fuselage section is presented. The paper also provides an in-depth analysis in the deformation mechanism of the fuselage section under a vertical crash, which will be helpful to effectively prevent the cabin floor from heavily damage and maintain the integrity of the fuselage section.

Abstract: This disclosure is directed to an unmanned aerial vehicle (“UAV”) that transitions in-flight between vertical flight configuration and horizontal flight configuration by changing an orientation of the UAV by approximately ninety degrees. The UAV may include propulsion units that are coupled to a wing. The wing may include wing segments rotatably coupled together by pivots that rotate to position the propulsion units around a center of mass of the UAV when the fuselage is oriented perpendicular with the horizon. In this vertical flight configuration, the UAV may perform vertical flight or hover. During the vertical flight, the UAV may cause the wing to extend outward via the pivots such that the wing segments become positioned substantially parallel to one another and the wing resembles a conventional fixed wing. With the wing extended, the UAV assumes a horizontal flight configuration that provides upward lift generated from the wing.

Abstract: A multi-engine aircraft is disclosed which is convertible from horizontal flight mode to a vertical flight mode. The aircraft comprises an aircraft fuselage defining a fuselage longitudinal axis, and the first and second wing attached to the fuselage. Each wing defines first and second wing segments. The first segments are translatable about the fuselage longitudinal axis, from a horizontal mode position adjacent the second wing segments to vertical fight mode wherein the first wing segment are substantially offset from the second wing segments. An aircraft propulsion unit is attached to each of the first and second wing segments. The propulsion units attached to a common wing being disposed in substantial axial alignment when the aircraft operates in a horizontal flight mode, and being substantially offset when the aircraft operates in a vertical flight mode. A sensor unit is connected to a forward portion of the fuselage.

Abstract: Purpose – The deformation of a large fuselage panel is unavoidable due to its weak-stiffness and low-rigidity. Sometimes, the assembly accuracy of the panel is out of tolerance. The purpose of this paper is to propose a method to predict and correct the assembly deformation of a large fuselage panel during digital assembly by using a finite element (FE) analysis and partial least squares regression (PLSR) method. Design/methodology/approach – A FE model is proposed to optimize the layout of load-transmitting devices to reduce panel deformation after the process of hoisting and supporting. Furthermore, another FE model is established to investigate the deformation behavior of the panel. By orthogonal simulations, the position error data of measurement points representing the precision of the panel are obtained. Then, a mathematical model of the relationship between the position errors of measurement points on the panel and the displacements of numerical control positioners is developed based on the PLSR me...

Abstract: Aircraft have evolved into extremely complex machines that require adapted tools to allow efficient design process. A performance formulation based on an exergy balance is under development at ONERA for assessing future aircraft configurations. A control volume analysis is performed to relate the exergy supplied by the propulsion system, its partial destruction within the control volume and the aircraft mechanical equilibrium. The formulation does not rely on the expression of thrust and drag and is therefore especially suitable for the performance evaluation of blended-wing bodies with boundary layer ingestion. A first step towards such applications is the investigation of a more academic configuration consisting in the ingestion of the complete wake of a simplified fuselage. Investigation is made via 3D RANS computations and it is shown that the benefit is due to lower levels of exergy destruction in the wake/jet of the BLI configuration.

Abstract: An aircraft takes off, lands, or hovers with at least one wing-mounted thrust-producing device attached to at least one wing of the aircraft and at least two fuselage-mounted thrust-producing devices attached to a fuselage of the aircraft both providing vertical thrust. The aircraft is flown while the at least one wing-mounted thrust-producing device provides horizontal thrust and with the at least two fuselage-mounted thrust-producing devices not providing any thrust.

Abstract: A vertical take-off and landing (VTOL) aircraft is provided and includes a fuselage, inboard wings extending from opposite sides of the fuselage to define a support plane and engine nacelles disposed along the wings. Each of the wings includes ground alighting elements and a variable geometry such that a portion of the ground alighting elements are alignable with the support plane during in-flight conditions and displaceable from the support plane.