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Improved Electromechanical Actuators for Aircraft Carrier Flight Deck Applications


OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Human-Machine Interfaces OBJECTIVE: Improve the existing configuration of Electromechanical Actuators (EMAs) to lower in a safe, controlled manner in the event of a system or component failure for Aircraft Carrier flight deck applications. DESCRIPTION: Aircraft Launch and Recovery (ALRE) is a critical part of aircraft carrier flight deck operation as the carrier aviation depends on the system for launching and landing aircrafts during flight deck operations. ALRE includes Jet Blast Deflectors (JBDs), Integrated Catapult Control System (ICCS), Barricade Stanchions, and Landing Signal Officer Display Systems (LSODS) , which utilize EMAs as the mechanism to raise and lower the operative components. EMAs are an alternative to hydraulic actuators, which require which require multiple hydraulic pumps that require pumps, pipes, and valves and lead to fluid contamination, oil leakage, or fire due to hot breaks. EMAs convert electricity to motive force. The force created can be used to move large doors, operate switches for sorting conveyor systems, or move powered valves. Commercially EMAs are used in platforms such as landing gear, steering actuation, doors, brakes, and primary and secondary flight controls. In the Navy, EMAs are used extensively on the CVN78 flight decks to raise and lower JBDs, Integrated ICCS, Barricade Stanchions, and LSODS. Existing EMAs are unable to lower in the event of mechanical or select electrical failures, creating a risk to flight deck operations, including loss of aircraft. JBD unit number three (3) poses the greatest risk to emergency flight recovery operations, which elevates the focus to develop a solution specific to this location. However, the need to improve reliability and reduce maintenance requirements persists for all flight deck EMA applications. The existing EMAs that actuate the JBDs are ineffective at lowering in the event of system or component failure, which poses significant risk to emergency aircraft recovery. There have been several documented cases of prevented JBD panel lowering incidents on aircraft carriers and successful outcome of this project is considered critical in support of carrier flight operations and in direct support of mission readiness. The current EMA applications, specifically on JBD 3, creates a critical need for a solution for an improved EMA that will lower in a safe, controlled manner in the event of a system or component failure. During aircraft carrier launch operations, the JBD functions as a physical safety barrier between the aircraft engine-nozzle exhaust and any equipment or personnel that are located behind the aircraft. A JBD is installed directly aft of each catapult and consists of either four or six aluminum panels. These panels raise from the flight deck and, in operational position, divert the aircraft’s jet blast upward. The panels become an integral part of the flight deck surface when lowered to their stowed position. The focus of this SBIR topic is to improve the current EMAs that actuate JBDs for safe and rapid manually-controlled lowering capability during emergency operations due to system or component failure. This action would ideally occur remotely, however, if a proposed solution occurs locally, then the time to deploy and activate the lowering action will be a major evaluation factor in meeting the time requirement. The JBD actuators exist in a severe environment where frequent exposure to seawater, jet fuel, grease, and other debris, and includes periods of submersion from accumulation of these elements. The JBD must remain raised if there is a loss of normal operating power and emergency lowering must commence upon manual control only. The physical space is highly constrained due to their proximity to other ship structure, systems, and components. The existing space dimensions are 14L x 36W x 1.8H feet with an approximate volume of 600 square feet occupied by in-situ machinery. Below are the requirements and technical data for JBDs. Dimensions: 6 feet wide with six (6) panels operating simultaneously in adjacent series along the length dimension at 14 feet and raised to a height of 10.7 on the aft arrangement. They raise simultaneously to an angle of 50 degrees from a horizontal position relative to the flight deck. Weight of Existing Panel: 5,200 lbs. Static Force (needed to overcome the weight of each panel): 38,000 lbs. Time to Lower (in the event of system or component failure):not more than 12 minutes. Method of Lowering: initiated manually, either remotely or locally. Safety Risks: must not pose any human-machine interface safety risks. NOTE: Technologies that achieve fully-lowered JBDs in the safest manner, which could entail remote operation, and in the shortest time will receive evaluation preference. Technologies that introduce the least time consuming maintenance requirements will also receive evaluation preference. The current design employs a mechanical clutch that disengages the EMA from the actuator and a mechanical brake that controls the descent rate of the JBD lowering action. Consideration should be given for alternative technologies that effect a manually-controlled emergency lowering operation such as locally or remotely controlled electro-hydraulics, pneumatics or other compressed gas cylinders and rams; coil springs; electro-magnetic cushioning; or any other novel dynamic control technologies, devices, or materials, or any configurations thereof that would integrate any existing means for lowering large heavy hinged objects in a rapid and safe manner under manually-controlled operation. Further consideration could also be given to effect a cascading action by leveraging raised panels as resistance in lowering adjacent panels in subsequence, thereby limiting the power demands to the final remaining upright panel. PHASE I: Develop a concept for improved EMAs for Aircraft Carrier Flight Deck applications that meet the requirements in the Description. Demonstrate the feasibility of the concept in meeting Navy needs and establish that the concept can be developed into a useful product for the Navy. Feasibility of the electromechanical actuator will be established via computer modeling. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II. PHASE II: Develop and deliver a prototype and demonstrate that it can meet the needs of the Navy. Initial testing of the system will be on subscale demonstrators progressing to full-scale system testing at a location and facility to be determined. Testing must demonstrate performance, environmental robustness, shipboard shock and vibration, and maintainability. Product performance will be demonstrated through prototype evaluation, modeling, and demonstration over the required range of parameters. An extended test in a maritime environment will be used to refine the prototype into a design that will meet Navy requirements. Prepare a Phase III manufacturing and development plan to transition the electromechanical actuators to Navy use. PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the EMAs to Navy use. Manufacture and install, on a candidate Gerald R. Ford and Nimitz Class aircraft carrier, one EMA system for shipboard test and evaluation. Plan to produce units for forward fit to CVN-81 and follow, and back-fit of the entire class of in-service carriers. Improved speed, precision, movement, and manual override to EMAs can be a substitute in any format or industry where this technology is currently being utilized such as mechanical systems, industrial machinery, computer peripherals, printers, opening and closing dampers, locking doors, braking machine motions, 3d printers, and commercial aircraft manufacturing. REFERENCES: 1. McGee, Tim & Johnson, Warren “Advances achieved from use of Electromechanical Actuators for the FORD-Class carrier’s Jet Blast Deflectors.” Curtiss-Wright. American Society Naval Engineers. April 2019, 2. Kovnat, Alexander R., “Electromechanical Actuators for Active Suspension Systems”. U.S. Army Tank-Automotive Research, Development and Engineering Center, November 1996, KEYWORDS: Aircraft Carriers; Electromechanical Actuators; Aircraft Launch and Recovery; Jet Blast Deflectors; Flight Deck operations; Emergency Lowering of JBDs.
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