Lighter Aircraft Research Articles

Mechanical strength of the aircraft control chains in certain unusual cases

The paper focuses on certain specific occurrences involving sports aircraft and their mechanical flight control chains. Usually the flight controls and their control chains are subject of thorough checking procedures, but frequently such details are not observed or are easily ignored during the maintenance and airframe checking processes. The authors aim to provide information enabling proper training of flight crews, technical, and design staff/ personnel, allowing the avoidance of severe occurrences/ events caused by failures of the mechanical control chains. The analysis focuses on lighter aircraft, such as sports aircraft, which have full mechanical control chains.

Closed-Loop Recycling and Remanufacturing of Polymeric Aircraft Parts

The aviation industry is facing the challenge of reducing fossil fuels and emissions. Fuel efficiency is improved by making efficient powerplant systems and lighter aircraft. Modern passenger aircraft utilize polymeric and polymeric composite materials to achieve lighter structures without compromising strength. The European Union already has legislation to prevent landfilling and to increase the use of recyclable materials in the automotive industry. While older-generation aircraft, made mainly from metallic materials, are easily dismantled and recycled into other uses, such a process does not yet exist for aircraft made from composite materials. In the coming years, the industry will have to answer the question of how retired polymeric composite aircraft structures are to be recycled. One solution to increase the life cycle of polymeric and polymeric composite parts would be closed-loop recycling. In this paper, a perspective of the closed-loop recycling of polymeric aircraft parts is discussed. The technical aspects of recyclability and the different business models for the remanufacture of a finger pinch shroud certified for use in Airbus A350-900 passenger aircraft are investigated. The results show that closed-loop recycling is possible for polymeric aircraft parts. Future studies could include studying an LCA between virgin and recycled materials for a certain part.

Simulation Study of a Composite Landig Gear of Ultralight and Very Light Aircraft

There is a need to design new, lighter aircraft structures, which has a direct impact on the safety and costs of aircraft maintenance. One of basic parts of an aircraft is ites landing gear, whose main functions are to enable taxiing, safe landing, take-off, and to assist the remainder of ground operations. Landing gear failures are usually related to metallurgy, processing, environment, design, and causes of overload. These are conditions that can be prevented using modern methods to calculate the strength of such a landing gear in various conditions. The paper presents stages of a simulation study of the fixed three-wheeled spring landing gear for an ultralight aircraft. Analysis of forces acting on the landing gear during drop test and their implementation by numerical computer methods allowed for the creation of a model in the CAD (Computer-Aided Design) tool and its FEA (Finite Element Analysis). These results were compared between a modeled classic spring landing gear and the one made of composite materials. The further goal of the research will be to build a drop test stand for a small landing gear used in airplanes and drones. This method has a significant impact on simplifying the design of the landing gear, its modeling, and optimization.

On the Importance of Nonlinear Aeroelasticity and Energy Efficiency in Design of Flying Wing Aircraft

Energy efficiency plays important role in aeroelastic design of flying wing aircraft and may be attained by use of lightweight structures as well as solar energy. NATASHA (Nonlinear Aeroelastic Trim And Stability of HALE Aircraft) is a newly developed computer program which uses a nonlinear composite beam theory that eliminates the difficulties in aeroelastic simulations of flexible high-aspect-ratio wings which undergoes large deformation, as well as the singularities due to finite rotations. NATASHA has shown that proper engine placement could significantly increase the aeroelastic flight envelope which typically leads to more flexible and lighter aircraft. The areas of minimum kinetic energy for the lower frequency modes are in accordance with the zones with maximum flutter speed and have the potential to save computational effort. Another aspect of energy efficiency for High Altitude, Long Endurance (HALE) drones stems from needing to minimize energy consumption because of limitations on the source of energy, that is, solar power. NATASHA is capable of simulating the aeroelastic passive morphing maneuver (i.e., morphing without relying on actuators) and at as near zero energy cost as possible of the aircraft so as the solar panels installed on the wing are in maximum exposure to sun during different time of the day.

Airbus Packing at Federal Express

Success in the express-mail market hinges on paying attention to every parcel in the system. A key component is safe, efficient loading of aircraft. Federal Express, a perennial leader in the express business, has recently added the Airbus A300, a lighter aircraft, to its fleet. Because of the Airbus design, shear limits—shear being a measure of the downward forces exerted on the plane—are extremely sensitive to the loading, a problem not experienced in the heavier craft. We developed a heuristic for loading containers into positions on the aircraft to address loading preferences and maintain feasibility constraints.