Browse Topic: Rescue operations
Helicopters' Vertical Take-Off and Landing (VTOL) capabilities are essential for maritime operations, especially for small-deck naval vessels. Unmanned Aerial Vehicles (UAVs) offer a cheaper, expendable, and efficient alternative for certain tasks, such as reducing pilot risk and lowering fuel consumption. While the procedures to approach and land on (moving) ships are standardized and bound to established operational limits in the case of crewed helicopters, UAVs lack such guidelines. This study investigates optimal rotary-wing UAV approach trajectories to a moving ship, for varying wind conditions and relative initial positions, and for different objectives. The goal is to provide preliminary guidelines for maritime UAV recovery operations, and a preliminary estimation of performance-based operational limits. The optimal trajectories are obtained using a global path-performance optimization framework based on Optimal Control Theory. The trajectories are compared to each other and to
Refueling mid air is considered as important force multiplier for e.g. conducting search and rescue operations. Due to close proximity to the tanker, the refueling hose and drogue as well as the receiver can be strongly affected by the tanker's wake. Thus, the refueling drogue extended from the tanker by a hose is often oscillating from turbulence. Contact with the tanker has to be established by positioning the receiver's refueling probe within the tanker's drogue. During qualification training pilots are instructed to not focus on the drogue, due to its oscillations. This is done since chasing the drogue often leads to over-controlling and therefore mostly to a failed contact attempt. The presented research aims for improving today's Helicopter Air-to-Air Refueling (HAAR) as well as related training efficiency by a gain of understanding in this phenomenon. Therefore, the HAAR real-time simulation scenario at German Aerospace Center's (DLR) Air Vehicle Simulator (AVES) was extended
Abstract Transient numerical simulations are conducted over a NACA 0012 airfoil with triangular protrusions at a Reynolds number (Re) of 100000 using the γ-Reθ transition Shear Stress Transport (SST) turbulence model. Protrusions of heights 0.5%c, 1%c, and 2%c are placed at one of the three locations, viz, the leading edge (LE), 5%c on the suction surface, and 5%c on the pressure surface, while the angle of attack (AOA) is varied between 0° and 20°. Results obtained from the time-averaged solution of the unsteady Navier-Stokes equation indicate that the smaller protrusion placed at 5%c on the suction surface improves the post-stall lift coefficient by up to 59%, without altering the pre-stall characteristics. The improvement in time-averaged lift coefficients comes with enhanced flow unsteadiness due to vigorous vortex shedding. For a given protrusion height, the vortex shedding frequency decreases as the AOA is increased, while the amplitude of fluctuations in lift coefficient
xEVs involved in incidents present unique hazards associated with the high voltage system (including the battery system). These hazards can be grouped into three categories: chemical, electrical, and thermal. The potential consequences can vary depending on the size, configuration, and specific battery chemistry. Other incidents may arise from secondary events such as garage fires and floods. These types of incidents are also considered in the recommended practice (RP). This RP aims to describe the potential consequences associated with hazards from xEVs and suggest common procedures to help protect emergency responders, tow and/or recovery, storage, repair, and salvage personnel after an incident has occurred with an electrified vehicle. Industry design standards and tools were studied and where appropriate, suggested for responsible organizations to implement. Lithium ion (Li-ion) batteries used for vehicle propulsion power are the assumed battery system of this RP. This chemistry is
ABSTRACT The Royal Australian Navy completed a series of First of Class Flight Trials in 2015 to establish Ship Helicopter Operating Limitations for Australian Defence Force rotary wing aircraft to the Canberra Class Landing Helicopter Dock (LHD). A Risk Reduction Tool (RTT) was developed to understand the impact of LHD airflow behavior on rotary wing operations. Specifically, the tool combined a ship air wake, a flight dynamic and a Pilot Model to provide an indicative effect of the air wake on pilot controls throughout an MRH90 recovery evolution. A verification of this tool suggests that the RRT in isolation was not able to characterize the flight environment with sufficient fidelity to predict pilot workload during recovery operations to the LHD. However, the RRT improved upon the information provided through stand-alone ship air wake analysis and as such the tool is suitable as a risk reduction measure prior to flight testing.
ABSTRACT This paper describes the continuing development work being undertaken to establish Flying Qualities Requirements for Unmanned Aircraft Systems (UAS) that will be expected to operate in the Maritime Environment. A UAS Dynamics Model (UDM) has been developed to allow the rapid investigation of the aircraft dynamics required to conduct ship-deck launch and recovery operations. The process used to develop the UDM is described along with the method used to fix the UDM dynamics to ADS-33E-PRF style bandwidth criteria. Two turbulence model structures are described and a preliminary test of the model dynamics in the lateral axis is reported. The model has been initially configured to assess an SH-60B-class UAS operating from a Type 23 Frigate. These preliminary investigations show that the methods being pursued hold promise to achieve the project aims.
While helicopters are used for a myriad of purposes in rural and urban environments, their true potential can be measured by the support they can offer in extreme and remote areas. This paper describes a Northern Canadian operator, Universal Helicopters Newfoundland and Labrador LP, the equipment used, the tasks performed, the working conditions and the risks and challenges faced . The principal areas of operation include the Province of Newfoundland and Labrador, the Ungava Peninsula and Canada's high and eastern Arctic. The company operates 19 light and intermediate helicopters in one of the most challenging environments in the world. The aircraft are equipped with operational equipment and accessories for operation in temperature extremes which test not only the machinery but the crews that fly and maintain them. A Safety Management System is in place to properly identify and manage the unique risks of operating in the north as well as logistical support that recognizes associated
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