Browse Topic: Landing gear
Tire is the only part of the aircraft that contacts the ground, which not only bears the vertical load and lateral load of the whole aircraft, but also provides adequate ground friction to decelerate the aircraft when braking, so the tires are important parts for aircraft take-off and landing. Besides safety concerns, tire physical properties such as vertical, lateral stiffness as static performance and rolling relaxation length, yawed rolling cornering force as dynamic performance are often required by aircraft manufacturers for analyzing aircraft maneuverability. Besides analysis or similarity by experience from other aircraft projects, tires are often qualified by a number of tests, both static and dynamic, to ensure the safety of tires and acquire tire physical performance data.
Advanced motion control technologies are essential to modern aerospace design, supporting a wide range of safety-critical and comfort-driven applications. In aerospace, motion control components such as gas springs, actuators, and dampers are integral to nearly every commercial aircraft, rocket, satellite, and space vehicle. These critical elements support flight safety and transport functions, from the dependable deployment of landing gear and cargo doors to the smooth, ergonomic operation of seating for pilots and passengers.
With advanced air mobility (AAM) vehicles becoming an increasingly popular topic in aviation, the Eagle Flight Research Center (EFRC) at Embry-Riddle Aeronautical University continues to investigate control strategies that enhance aircraft resilience to total power unit failures. Utilizing a distributed electric propulsion (DEP) quad-heli test bed, the EFRC has explored a variety of control laws and hardware configurations to evaluate their effectiveness under failure conditions, including sustained flight with a completely inoperative rotor. The aircraft utilizes a fractional-order PID (FOPID) controller that has recently been developed and shown to outperform conventional PID controller used previously in both nominal and failure scenarios. The use of a FOPID controller offers improved stability and tracking performance. Another development is the implementation of a split-rotation rotor configuration—where the left-side rotors rotate clockwise and the right-side rotors rotate counterclockwise—which, when combined with a control law leveraging cyclic rotor inputs for yaw control, provides a robust alternative to conventional quadrotor designs. This configuration leverages the redundancy offered by equipping each of the aircraft's four rotors with full helicopter controls, enhancing the potential for sustained flight in the event of two rotor failures while preserving the maneuverability and controllability characteristic of the conventional configuration. Additionally, to support expanded testing and operational capability, the aircraft has been outfitted with a custom-designed landing gear system, designed and fabricated by the EFRC team.
Performing highly representative tests of aircraft equipment is a critical feature for gaining utmost confidence on their ability to perform flawlessly in flight under the entire spectrum of operating conditions. This can also contribute to accelerate the certification process of a new equipment. A research project (E-LISA) was performed in recent years, as part of the European funded Clean Sky 2 framework, with the objective of building an innovative facility for testing an electrically actuated landing gear and brake for a small air transport. The project eventually led to the development and construction of an Iron Bird able to reproduce in a realistic and comprehensive way a full variety of landing test cases consistent with certification specifications and landing histories available in the repository of the airframer. The Iron Bird that was eventually developed is a multi-functional intelligent and easy reconfigurable facility integrating hardware and software allowing to perform a full verification and validation of an electrically actuated landing gear and brake over the representative operating conditions, and under normal, degraded and faulty conditions.
This Aerospace Information Report (AIR) will examine considerations relative to the use of mechanical switches on aircraft landing gear, and present "lessons learned" during the period that these devices have been used.
This SAE Aerospace Recommended Practice (ARP) establishes a procedure for disposition of aircraft wheels that have been involved in accidents/incidents or have been exposed to overheat conditions or overload conditions from loss of adjacent tire pressure (paired wheels) or wheel tie bolts.
With regards to any aerospace mission, it is very useful to have awareness about the state of vehicle, i.e., the information about its position, velocity, attitude, rotational rates and other concerned data such as control surface deflections, landing gear touchdown, working of mechanisms and so on. The sensor data from the vehicle that is communicated to the ground can be difficult to perceive and analyze. A frame work for real-time motion simulation of an aerospace vehicle from onboard telemetry data is henceforth developed in order to improve the understanding about the current state of the mission and aid in real-time decision making if required. The telemetry data, that is transmitted through User Datagram Protocol (UDP), is received and decoded to usable format. The visualization software accepts the data in a fixed time interval and applies the required transformations in order to ensure one-to-one correspondence between actual vehicle and simulation. The transformations required for missions with various scope are formulated. Data handling scheme for low frequency data and data loss are also discussed. The importance of environment design emphasized, the 3D terrain is created from satellite imagery and heightmap or digital elevation model. The shader for volumetric atmosphere useful for surface to space missions, is created using an algorithm that simulated scattering of light in the atmosphere. For larger environments required for launch vehicle missions, a scaling scheme is worked out and is implemented in combination with the floating-origin algorithm to deal with the floating-point limitations posed by current generation graphic engines. Techniques such as quad-tree structures for level of detail (LOD) rendering are used for optimization of performance. Animation of flight events are rigged and get triggered based on flags in telemetry data. The developed framework was tested in critical demonstration missions for ISRO – The Reusable Launch Vehicle Landing Experiment (RLV-LEX) and Test Vehicle Demonstration Mission -1 (TV-D1). The framework can be used for a variety of missions such as launch vehicles, spacecrafts, UAVs and even landers & rovers.
Items per page:
50
1 – 50 of 638