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Aircraft development projects at Bombardier Aerospace involve a large number of tasks executed by a network of professionals from various disciplines. As the complexity of products and the development process increases, it becomes more difficult to manage the interactions among tasks and people. In fact, it may be impossible to even predict the impact of a single design decision across the development process. At Bombardier, investigation has shown that there was a lack of communication between design processes when dealing with aeroelasticity information. This resulted in duplicated design effort, reduced quality, and increased time to complete tasks when small design changes from one task induced delays in other tasks. Processes that deal with aeroelasticity work integrate system inertial, aerodynamics and structural information to make aircraft models and perform analyses. These processes have been creating similar models to perform aeroelasticity analyses.

Numerous pyrotechnic devices have been employed in satellite launch vehicle missions, generally for the separation of structural subsystems such as stage and satellite separation. The detonation of the pyrotechnic devices generates shock waves characterized by high accelerations and vibrations which cause the failure of electronic components. To reduce the possibility of failure, many researchers have attempted to develop various experimental and numerical simulation methods for investigating pyroshock behavior to determine the appropriate placement of sensitive equipment. However, most of those methods have limitations such as low flexibility and high costs in the experimental methods and relatively low efficiency and reliability in the numerical methods. This study proposes a simple experimental method for pyroshock prediction using only laser pulse excitation and in-line filters for composite structure.

Air to Air refueling (AAR) operations are typically performed with dedicated tanker A/C. Most existing tankers are derived from civil airliners like the A330MRTT from Airbus Military or from military transport A/C with permanent modifications for the tanker role. For being able to refuel in flight some type of receivers like medium and light turboprops, helicopters and certain UAVs, the tanker aircraft should be able to fly at low speeds. For that role medium/small size turboprop military transport aircraft, like the C295 from Airbus Military are ideally suited. This paper proposes a new palletized AAR kit for conversion of a transport A/C into a tanker. The kit includes all the needed air refueling systems, and can be installed on an existing military transport aircraft with rear cargo door ramp without big permanent modifications to the base platform.

During an aircraft development, mathematical models are elaborated from its characteristics, physical laws and modeler prior knowledge of the system. Once the aircraft built, those models (mainly linear models) are tuned with flight test recorded data. Regulation authorities define the precision needed for such models. The purpose of this paper is to build an aircraft global model complying with regulation authorities' accuracy requirements with minimal prior knowledge of the system. A professional D level simulator has been used as a flight test aircraft. More than 1,000 experimental flight tests were made with numerous configurations in speed (140 to 240 kt), altitude (10,000 to 46,300 ft), mass (24,000 to 33,000 lb) and the center of gravity position (17 to 34 % of the mean aerodynamic chord). Aircraft's global model is built by identifying linear models at flight points within aircraft flight envelop and the center of gravity limits.

In this paper, we describe a practically efficient methodology of improving the aerodynamic characteristics of an UAS's wing using a morphing approach. We have replaced a part of the original wings' upper and lower surfaces with a flexible, composite material skin whose shape can be modified, according to the variable airflow conditions, using internally placed actuators. The optimal displacements of the actuators, as functions of the external flow characteristics, are determined using a genetic algorithm based optimizer, coupled with a three - dimensional numerical extension of the classical lifting line model for estimating the modified wing aerodynamic coefficients. We have used the optimization tool to decrease the overall drag coefficient of a military grade UAS' wing equipped with the flexible skin. We have obtained good quality solutions for only a fraction of the computational cost needed when performing viscous flow field calculations.

This paper proposes a control method to remotely operate cooperative multiple heterogeneous slave unmanned aerial vehicles (UAVs) via a single master robot to perform different tasks on different targets in one mission. The UAV team is formed by different automated aircrafts. They are equipped with a vehicle-task-target pairing algorithm to be assigned their proper tasks and targets when moving in a leader-follower formation to track and perform assigned targets and tasks, respectively. The proposed leader-follower formation control method is modified based on a potential field algorithm to guide the UAV team or sub-team. In the UAV team, only a single leader vehicle is teleoperated by a human operator while all other follower vehicles autonomously form the formation regarding the leader movement. Therefore, the number of long distance transmission links between UAVs is reduced to minimize the possibility of occurrences of large communication delays.

In today's assembly of large complex Carbon Fiber Reinforced Plastics (CFRP) components, e.g. vertical tail planes (VTP) of modern passenger aircrafts, liquid resin-based materials are used for several applications. Commonly, liquid resin-based materials are used to close gaps between the CFRP single parts during assembly (shimming) or to smoothen outer surfaces to fulfill aerodynamic requirements (aerodynamic sealing). Curing times of standard resin-based materials vary between eight to twelve hours at room temperature under normal shopfloor conditions regarding air humidity. In running aircraft production such long curing times are definitely waste in the sense of lead time. By heating these resin-based materials the common curing time can drastically be reduced down to two hours. By using heated air - instead of e.g. heating lamps - the curing process can reliably be controlled, without any risk of overheating and destroying the sealant or shim material.

The assessment of the service durability of aerospace components and assemblies has become an important segment of design. In order to meet strict safety requirements, a number of complex and long experiments are carried out. The use of finite element method (FEM) and extended finite element method (XFEM) for the estimation of fatigue life and fatigue crack growth predictions has been proved as a good alternative to the expensive experimental methods. In this paper, both experimental and numerical analyses of 2024-T3 aluminum spar of a light aircraft under variable amplitude loading are presented. FEM has been used for estimation of the spar life to crack initiation, whereas XFEM has been used for fatigue crack growth predictions and fatigue life estimation of damaged spar. The values of stress intensity factors were extracted from the XFEM solution in MorfeoCrack for Abaqus software.

Unlike the conventional bleed-air method, using electro-thermal anti-/de-icing methods to completely evaporate all of the supercooled water droplets that collide with the leading edge wing surface of aircraft flying in a freezing environment is not easy in terms of technical feasibility and energy efficiency[1]. If the leading edge is warm enough to stay free from frozen water droplets, the water moves backward while still maintaining the liquid phase. The droplets may freeze somewhere on an unheated surface after being halted for some reason and stick on the surface. Ice gradually accumulates as this process is repeated. Therefore, liquid water must be removed from the surface as soon as possible if the electrothermal method is employed for icing prevention. One answer to this problem is coating the surface with a superhydrophobic paint.

The first cross-industry guidelines for the implementation of structural health monitoring for aerospace applications have been created as a SAE International Aerospace Recommended Practices document: SAE ARP 6461 ‘Guidelines for Implementation of Structural Health Monitoring on Fixed Wing Aircraft’ [1]. These guidelines have brought together manufacturers, operators / users, systems integrators, regulators, technology providers and researchers to produce information on the integration of SHM into aircraft maintenance procedures, generic requirements and advice on validation, verification and airworthiness. The take-up of SHM in the aerospace industry has been slow, in part due to the lack of accepted industry practices surrounding not just the technology itself (sensors and sensor systems) but also the associated issues arising from the introduction of new methods into aircraft maintenance.

On September 30, 2011, certification authorities released Advisory Circular 20-174[1], Development of Civil Aircraft and Systems, which recognizes the Society of Automotive Engineers (SAE) Aerospace Recommended Practice (ARP) 4754A and the European equivalent ED-79A [2], in order to address “the concern of possible development errors due to the ever increasing complexity of modern aircraft and systems.” ARP4754A/ED-79A describes a process of development assurance which helps reduce the risk of design errors in the development of aircraft systems. This process is necessary for complex systems not easily comprehended by deterministic analyses or tests. This ARP was developed “in the context of Title 14 of the Code of Federal Regulations (14 CFR) part 25,” a category which includes complex systems such as full fly-by-wire flight controls. However, this paper shows that such systems are the exception to most, recent civil airplane designs.

This paper is devoted to a method of creating of the automated ballonet system for pressure control inside an airship envelope. Along with the study of the effects of the positional control system parameters, the authors develop novel control scheme. It is based on a new hybrid controller, which combines positional approach to forming the output control signal with a contour of continuous correction of input signal, which defines the pressure drop on the surface of the envelope as a function of the flight altitude. This approach allows reducing the effect of self-oscillations of airship envelope internal pressure on the flight altitude. In order to prove the new approach the mathematical model is being obtained. The results of the derivation and simulations of the control system operation are presented in this paper.

We live in an era of increasing twin-engine commercial airplane operations, with large and very quiet high bypass ratio engines. At the same time, due to several decades of increased attention to the environment, we have large and increasing hazardous species bird populations. These trends, when combined, are not a prescription for continued assurance of a remarkable and enviable safety record for commercial aviation. Therefore, greater diligence must be placed on the evaluation of the current and future aviation wildlife hazard. We have some new weapons in this fight for greater capability to live with this situation. The basic problem is that different databases are populated independently from one another and often contain conflicting, contradictory, and erroneous data. Databases that were used individually, but not necessarily combined, are being utilized in a conjoined methodology to give us a better picture of the actual risk involved.

Reducing greenhouse gas emissions to limit global warming is becoming one of the key issues of the 21st century. As a growing contributor to this phenomenon, the aeronautic transport sector has recently taken drastic measures to limit its impact on CO2 and pollutants, like the aviation industry entry in the European carbon market or the ACARE objectives. However the defined targets require major improvements in existing propulsion systems, especially on the gas generator itself. Regarding small power engines for business aviation, rotorcrafts or APU, the turboshaft is today a dominant technology, despite quite high specific fuel consumption. In this context, solutions based on Diesel Internal Combustion Engines (ICE), well known for their low specific fuel consumption, could be a relevant alternative way to meet the requirements of future legislations for low and medium power applications (under 1000kW).

Career paths are not something that one can predict. They are as much about being in the right spot at the right time with the desired skill set as they are about having a detailed, calculated plan. How does one go from being a young Original Equipment Manufacturer (OEM) test engineer to being an airline Senior Vice President of Safety, Security and Compliance and the joint industry/FAA co-chair of the Commercial Aviation Safety Team? It is a bit unusual that a non-pilot ends up on an airline Operations Specification listed as the Federal Aviation Regulations (FAR) Part 119 Director of Safety for one of the largest airlines in the world. Engineering background and experience were key stepping stones on that journey along with a healthy dose of skepticism. An initial assignment to make an airline's safety program robust, credible and data driven, much like the very successful aircraft reliability programs, set the direction and path forward.

Stringer misplacement in the latest design of full CFRP wing covers causes cost and lead time in the further processes due to reworks in the torsion box assembly., To improve and solve this matter, ARITEX has developed an automated Laser assisted Stringer positioning system that allows the flexible, one-by-one and accurate position of the non-cured Stringers in the wing cover. This paper describes how ARITEX has developed and implemented this system in two different CFRP wings using the same technical concept adapted to the context and geometry of each aircraft, and how the targets were achieved reducing the misplacement problem from previous projects.

This paper shows how the quantity demanded, viewed as an independent variable, interacts with customer values, producer costs and constraints. Failure to analyze Demand as Independent Variable (pronounced “Dave”) increases the chances that new programs will not launch, or once started, will fail. All producers in all markets face demand curves that describe their customers' reaction to price changes. Aggregate market demand curves show how buyers react to price changes within broad product sets, while product demand curves show buyer responses to a specific item. Demand curves relate quantities sold relative to their prices. In several military, transit and fleet cases, minimum quantity requirements form upper price boundaries along demand curves. Allowing prices to go so high that buying authorities cannot acquire the required numbers of units likely means that there may not be sufficient resources to form systems that can accomplish the buyers' goals.

The renewed interest in the fuel efficient and low CO2 emission CROR (contra-rotating open rotor) propulsion system for future commercial aircrafts has recently led to a series of isolated and installed CROR wind tunnel test campaigns performed in close collaboration between Airbus and the engine manufacturers. These tests aim at better understanding the potentials and limitations of the CROR configuration, as well as at generating reference data for the development and calibration of numerical tools for both industry and research centers. One of these tested CROR concepts is the AI-PX7 CROR propeller designed by Airbus. In this context, this paper presents multidisciplinary design features of modern high-speed contra-rotating propellers for commercial aircrafts. The influence of main CROR design parameters like blade number, propeller tip speed, rotor diameter, etc. on the propeller aerodynamics, acoustics and structures is described.

Many Small Unmanned Aerial Vehicles (SUAV) are driven by small scale, fixed blade propellers. Flow produced by the propeller can have a significant impact on the aerodynamics of a SUAV. Therefore, in Computational Fluid Dynamic (CFD) simulations, it is often necessary to simulate the SUAV and propeller coupled together. For computational efficiency, the propeller can be modeled in a steady-state view by using momentum source terms to add the thrust and swirl produced by the propeller to the flow field. Many momentum source term models are based on blade element theory. Blade element theory divides the blade into element sections in the spanwise direction and assumes each element to operate independently as a two-dimensional (2D) airfoil.

Implementing Design for Environment (DfE) into the design process requires a strategic integration. Furthermore, as DfE is continuously evolving, flexible processes need to be implemented. This article focuses on the integration of DfE into an optimization framework with the objective of influencing next-generation aircraft. For this purpose, DfE and Structures groups are developing together a set of new environmental indicators covering all life cycle stages of the product by coupling a list of yes/no questions with an environmental matrix. The following indicators are calculated: Regulation risk, Impact of manufacturing the part, CO2 emissions and Recyclability potential. These indicators will be used as constraints in the multi-disciplinary design optimization (MDO) framework, meaning that the structure will be designed while complying with environmental targets and anticipating future regulation changes.