MH-53E - Design
The MH-53E's triple turbine engines provide greater lift for mine countermeasures operations while enlarged sponsons carry additional fuel to allow up to six hours of time on station.The T64-GE-419 engine, AN/ARC-210(V), R-2606/U GPS, and AN/ARC-220 were retrofitted into the MH-53E by field modification teams or by the Naval Aviation Depot (NAVAVNDEPOT) Cherry Point, North Carolina, during scheduled Standard Depot Level Maintenance (SDLM). The minor changes to the MH-53E Helicopter were also be introduced into the fleet by field modification teams or during SDLM. The main gearbox ECP will be retrofitted on an attrition basis.
The MH-53E Helicopter is a CH-53E modified to perform AMCM missions. The modifications include:
- Enlarged sponsons
- Rear escape hatches
- Improved tail rotor system
- Airframe structural reinforcement
- 30,000-pound tension tow boom
- 90-degree stub ramp
- Winch control system
- AN/APN-217(V)2 Doppler Radar
- A second AN/APN-171(V) Radar Altimeter
- Improved mirrors
- Equipment stowage box
- Mk-104 davit hardpoints
- Egress lighting
- Guillotine, tension, and skew system
- Tow hook release system
- Transfer hook and control system
- Smoke marker rack
- XM-218.50 caliber machine gun
The new configuration features the airborne mine countermeasures coupled, dual digital automatic flight control system. The system consists of two digital computers, a cockpit control box, six accelerometers, and five position sensors. It is 42 percent lighter, occupies 54 percent less volume and consumes 41 percent less power than the older analog system. There is no organizational level maintenance required. The computers continually cross-check one another and disable any potential false inputs to the automatic flight control system servos. If one computer fails, the other will automatically double its output, eliminating any degradation in automatic flight control performance.
Also part of the new mine countermeasures capability is a dedicated AMCM hydraulic system, improved AMCM navigation, 30,000-pound tension tow boom, better mirrors and better crew environment. The MH-53E Super Stallion is capable of inflight refueling and can be refueled at hover. It is also shipboard compatible with amphibious ships serving as airborne mine countermeasures platforms. The aircraft will sweep waterways for mines by flying above the surface, towing electronic or magnetic sweeping gear as well as gear for neutralizing moored mines.
The MH-53E Helicopter retained approximately 80 percent of the CH-53E configuration. The physical changes include the larger fuel sponsons and auxiliary AMCM equipment. The newly designed sponsons each contain two fuel tanks. This allows for a total fuel capacity of 3,200 gallons, which will increase both aircraft range and loiter time. Two enlarged window-type escape hatches in the aft cabin area permit easier egress for aircrew in an emergency situation. An A-frame suspension system is stowed in the forward position.
The Tow Boom is a fixed length four-inch diameter composite tubing that increases towing capacity. The boom has 32 degrees of movement in the pitch plane, and can yaw about the vertical axis to either side of the cabin. The forward end of the boom is set in sleeve bearings to allow operating motion for a load cell that monitors tow loads.
The power for the MH-53E Helicopter was initially furnished by three T64-GE-416 or -416A Engines. Upgraded engines were installed on 14 MH-53E Helicopters out of 44 aircraft in the fleet. This new engine, the T64-GE-419, increases engine performance and allows for contingency power during a One-Engine-Inoperative condition. The Main Gearbox improvement program will provide greater reliability and an increased time between unscheduled removals. This redesign effort for fleet aircraft will be accomplished through an ECP. The MH-53E Helicopter has a modified CH-53E Hydraulic System consisting of an additional 3,000 pounds per square inch hydraulic supply system dedicated to AMCM.
In addition to the onboard fuel system, the MH-53E Helicopter has air-to-air and Helicopter-In-Flight Refueling (ship-to-air) pressure refueling systems, an inner tank fuel dump system, and a range extension fuel transfer system. The MH-53E Helicopter has enlarged fuel sponsons and uses a new fuel management system. There are three independent suction-pressure type fuel systems, one for each engine. The fuel systems are joined by a crossfeed system for maximum fuel utilization.
The flight station design for the MH-53E Helicopter differs from the CH-53E in the gages, switches, and circuit breaker panels necessary for effective AMCM aircraft operations. Some modifications to the flight station layout will result from the Navigation and Communication System integration. Due to the additional electronic equipment, the MH-53E Helicopter wiring system and circuit breaker panel have been redesigned.
The Digital Automatic Flight Control System Coupler System has been incorporated with modifications to the MH-53E Helicopter Digital Automatic Flight Control System (AFCS) computer. This provides longitudinal and lateral ground speed control, selected ground speed stabilization, and automatic altitude retention.
The AN/ARN-151 GPS is being replaced by the R-2606/U MAGR 2000 GPS, fully integrated with the aircraft navigation instruments and providing non-precision approach capability. The AN/APN-217(V)2 Radar Navigation Set is a Doppler radar that measures aircraft ground speed and drift angle. It has the unique ability to perform accurately at low airspeeds over smooth water. Additional navigation systems aboard the MH-53E Helicopter include two AN/APN-171(V) Radar Altimeters, the AN/ARN-118(V) Tactical Air Navigation (TACAN), AN/ARN-89A Automatic Direction Finder, VIR-31A Very High Frequency Omni Directional Radio (VOR)/Instrument Landing System (ILS) navigation system, and vertical gyro system.
The two AN/ARC-182(V) Radios provide direct securable communications in the Ultra High Frequency (UHF) and Very High Frequency (VHF) bands. When operated with a C-11984 Control Unit, the AN/ARC-182(V) provides a frequency hopping anti-jam capability in the UHF mode. Other communication systems aboard the MH-53E Helicopter include the AN/ARC-174A(V)2 High Frequency Radio, AN/APX-72 Identification Friend or Foe Transponder, KIT-1A/TSEC Computer Transponder, TSEC/KY-58 Secure Voice Data Set, and the AN/AIC-14A Intercom. The AN/ARC-182(V) Radio is being replaced by the AN/ARC-210(V) ECCM Radio System, and the AN/ARC-174 is being replaced by the AN/ARC-220 to provide a data-link capability. The AN/ARC-210(V) provides normal and secure communication in the Amplitude Modulation and Frequency Modulation modes in both UHF and VHF bands. It is compatible with the TSEC/KY-58, has frequency hopping jam-resistant capabilities, and is interoperable with other Air Force and Army radio systems.
The Airborne Mine Countermeasures Navigation includes the PNS, a navigation system that has been integrated with the AN/ARN-151 Receiver (which was part of the AN/ARN-151 provisions installation). It is used for precise mine field navigation during AMCM missions. The interim GPS functions are assumed by the R-2606/U GPS when integrated into the MH-53E Helicopter.
The AN/ALE-39 Countermeasures Dispensing System is mounted either internally or externally and is designed to dispense chaff, infrared decoy flares, or expendable jammers.
Several modifications to the MH-53E Helicopter are planned over the next few years. These modifications include upgrading to the T64-GE-419 engine, upgrading to the MAGR 2000 Global Positioning System (GPS), an Engineering Change Proposal to the main gearbox, and other minor Airframe Change modifications to the helicopter.
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