Military


CH-47F Improved Cargo Helicopter (ICH)

The Boeing Company announced on July 16, 2007, that it had received U.S. Army authorization for full-rate production and fielding of the new CH-47F Chinook helicopter. The CH-47F completed U.S. Army operational testing at Fort Campbell, Ky., in April 2007, and would then move forward with First Unit Fielding in July.

The CH-47F Improved Cargo Helicopter (ICH) is a remanufactured version of the CH-47D Chinook cargo helicopter with the new 4,868-horsepower Honeywell T55-GA-714A engines, enabling it to reach speeds greater than 175 mph and transport payloads weighing more than 21,000 lbs. The cost of a new CH-47F is $32 million. These costs are reduced to $8.5 million per aircraft by remanufacturing CH-47Ds to CH-47Fs with the CH-47F improved cargo helicopter (ICH) Service Life Extension Program. The ICH program was initiated to extend the service life of the CH-47 airframe, while reducing operations and support costs.

The current CH-47D cargo helicopter fleet is unable to support the requirements of a primarily CONUS based, contingency force. The operational capability that is critical to support this wide range of contingencies is not provided by current cargo helicopter systems without improvements. Existing cargo helicopters performed admirably in the past; however, the current capability erodes with an aging fleet. The first CH-47D aircraft reached their service life goal of 20 years in 2002 (Note: The CH-47D was remanufactured from CH-47 A, B, and C model aircraft). Continually increasing maintenance man-hour per flight hour rates, resulting from years of high use, are adversely impacting units' ability to maintain the fleet to Army standard. Increases in O&S costs, cargo weight, range requirements, operational tempo, emphasis on rapid self-deployability, and threat anti-aircraft capabilities have reduced the effectiveness of the CH-47D fleet. The CH-47D cannot communicate in the Army Force XXI digital battlefield network without new equipment.

The Improved Cargo Helicopter (ICH) will provide continued support, coverage, and sustainment for Maneuver, Fire Support, Air Defense, and Mobility and Survivability mission areas. The primary mission of the ICH is transportation of ground forces, class III and V supplies, and battle critical cargo in support of all future contingencies. The geographical mission area for the ICH is worldwide, anywhere aviation or ground operations are being conducted by U.S. Forces. Through its speed and agility, the ICH will meet time sensitive transport requirements for urgently needed armed forces, equipment, and supplies, that are not otherwise rapidly available from ground transportation systems. Missions will be conducted during day and night, adverse weather, and extreme environments across the range of operations from support of friendly host nations, primary regional conflicts, and high intensity battle.

The ICH program was intended to restore CH-47D airframes to their original condition and extend the aircraft's life expectancy another 20 years (total life of 60 years) until the 2025-2030 timeframe. The program was to remanufacture CH-47 aircraft, reduce the aircraft's vibration, thereby reducing Operations and Support costs, and allow the aircraft to operate on the Army XXI digitized battlefield by incorporating a 1553 data bus providing a digital communications and situational awareness capability. The ICH will also acquire the capability to carry 16,000 pounds of external/internal cargo for a 50 NM combat radius at 4000 feet pressure altitude and 95 degrees fahrenheit. In addition, the following improvements will be incorporated into the aircraft:

  • Fuselage stiffening and possible active systems for vibration reduction (this is expected to lead to improved reliability and therefore reduced operating and support costs)
  • Integrated cockpit
  • Digital architecture for Force XXI compatibility

Additional improvements may be incorporated into the aircraft if funding permits. The ICH will transport weapons, ammunition, equipment, troops, and other cargo in general support of combat units and operations other than war. The ICH is a dominant maneuver platform that provides focused logistics to the force. The ICH program was built as a "bare bones" program to satisfy the battlefield requirements of operations on the 21st century digital battlefield by replacing the existing 1970s technology cockpit with a new cockpit.

Airframe Rebuild includes work under which the airframe is remanufactured to "like new" condition. Operation and support costs are rebaselined. The remanufacturing process is similar to the CH-47D production process. The latest engineering change proposals are incorporated, and field deficiencies are corrected.

Vibration Reduction Modifications are based on the Vibration Reduction Test Aircraft (VRTA), which has been flying at Fort Rucker since November 1996. It incorporates stiffening of the airframe skin at the below locations. This stiffening will reduce vibration, stress, and fatigue on the airframe. It will result in improved crew comfort and increased component life which relates to reduced operations and support costs.

Air Transportability includes modifications to the CH-47's aft pylon structure and internal systems to allow quick removal for loading into C-5A transport aircraft. This air transportability kit includes modifications to the existing aft pylon attaching nuts and bolts, which are replaced with nutplates. Quick disconnects are used for the hydraulic lines. The aft fuselage structure is modified to allow the aft transmission to be lifted with the aft pylon.

The Improved Cockpit of the CH-47F(ICH) will retain the current CH-47D air vehicle monitoring suite and incorporate a Military Standard 1553 data bus to handle tactical data link, communications and navigation data. The new cockpit will provide modern technology controls and displays including multi-function displays, which will provide situational awareness for the flight crew via a moving digital map display with force symbol overlays and electronic messaging; control display units to provide data entry/control; and electronic flight instruments. The system also will ease cockpit workload and mission planning with the addition of a Data Transfer System that allows for loading/storing of preflight data, mission data and maintainer data. In addition to making the Chinook a cost-effective and capable digitized tactical platform, the upgrade will cut operations and support costs because reliable solid-state systems with built-in diagnostics will replace CH-47D analog avionics. The upgrade also provides an open architecture system to allow for future growth and technology insertions including advanced aircraft survivability equipment. Coupled with head up displays projected in night vision goggles, the avionics upgrade will greatly improve flight safety at night, especially for external load operations.

After an extensive assessment of several qualified avionics suppliers, Boeing selected Rockwell Collins to provide the integrated avionics suite of the Army's Chinooks as a major part of the CH-47F(ICH) program. The Collins system will ensure the Chinook can play an important tactical role on the digital battlefields. It features robust elements to withstand electromagnetic interference and electronic warfare measures, reliable components that are easier to maintain and repair, shipboard compatibility for joint and combined operations, and full compliance with Joint Technical Architecture - Army standards listed in the Army's CH-47F(ICH) Avionics Upgrade Performance Specification. That specification, developed as an outgrowth of a Navy Research Laboratory study, defines the requirements that will make the CH-47F(ICH) compatible with the digitized, Information Age battlefield envisioned for Army XXI and the Army After Next.

The Rockwell Collins CH-47F(ICH) configuration is a derivative of that currently flying on the MH-47D Special Operations Chinook and the RC-12, a U.S. Army fixed wing platform, making the new CH-47F(ICH) electronic architecture a low-risk developmental element in the program. Boeing and Rockwell Collins also will ensure the system matures in parallel with the evolving Army digitization initiatives. During the program's engineering and manufacturing development phase, the team will remanufacture two CH-47Ds to the CH-47F(ICH) configuration and test their operational suitability.

The CH-47F concept began to materialize in the early 90's following Desert Storm. The initial concept was a four bladed system called Aerial Cargo Transport (ACT) with long range external fuel tanks, internal cargo handling system, and low maintenance rotor system (dry hub). Unfortunately this concept was dropped as being too expensive. ODSCOPS recognized the heavy lift need but there was not enough money for a new start program. They directed an update of the current CH-47D Operational Requirements Document (ORD) to extend the life of the CH-47 fleet while maintaining an economic solution. The purpose of the CH-47F is to bridge the gap until the funding is available for a new aircraft start (FY 2020 timeframe). The cargo helicopter modernization plan includes the CH-47F as an interim fix until the Joint (Future) Transport Rotorcraft (JTR) is developed.

The new CH-47F Chinook prototype heavy-lift helicopter, the sixth Chinook type designed for the US Army, completed its first flight at the Boeing Philadelphia manufacturing facility on 25 June 2001. The flight, which involved hover and basic maneuvers, capped a series of comprehensive system checks leading to takeoff precisely as scheduled in the CH-47F program agreement completed three years earlier.

OSD's approval for entry into the engineering and manufacturing development (EMD) phase came in FY98 on perceived low-technical risk, and delegated Milestone decision authority to the Army Acquisition Executive. The program had experienced delays, changes to the Operational Requirements Document (ORD), cost overruns resulting in a Nunn-McCurdy breach, and significant program restructuring in FY02. The Army Acquisition Executive's approval for the purchase of up to 30 low-rate initial production aircraft occurred on August 19, 2002. The Army plans to conduct the IOT&E commencing on April 5, 2004, with the full-rate production decision occurring in early FY05.

A December 12, 2002, Program Decision Memorandum gave priority for production to the MH-47G (Special Operations Forces) over the CH-47F ICH. Significant differences between the two helicopters required a reconfiguration of the production line after the first CH-47F was complete and rolled off the line. Consequently, the Army planned to procure five fewer CH-47Fs to offset the production cost increase and postpone the fielding of the first unit of CH-47F aircraft until FY07.

Tests flying the aircraft from Fort Worth, Texas, to Phoenix, Arizona, to El Centro, California, and to Jupiter, Florida, not only attested to the aircraft's ability to self deploy, but provided the Army an opportunity to conduct and assess operational missions in desert, high-altitude, and tropic conditions. DOT&E and Army concerns involving the possibility of a migration or increase of vibration levels in the aft section of the aircraft prompted the conduct of a vibration/strain comparison test between the CH-47D and the CH-47F model.

According to the DOT&E, to date overall operational and system effectiveness are good. However, program goals for system reliability, vibration reduction, and digital interoperability may not be achieved.

Even though reliability testing to date confirmed that failures in the CH-47F were common to legacy CH-47D aircraft, these same testing results suggested that the CH-47F is at low to moderate risk to achieve ORD R&M thresholds.

Fatigue damage on the CH-47F aircraft is similar to damage found in legacy aircraft. However, higher vibration levels at the combiner cooling fan location raise concerns within the test community about the long-term reliability of aircraft components and the potential long-term impact on overall structure damage.

Testing on the CH-47F demonstrated the system's capability to send and receive selected digital messages between aircraft and a ground-based Force XXI Battle Command, Brigade and Below simulator. IOT&E will provide the opportunity to demonstrate aircraft-to-aircraft digital messaging, compatibility with Joint and Army technical architecture, and interoperability with a fully loaded tactical internet.

Test data from the Army's live fire test of the CH-47F and the DOT&E Joint Live Fire Program of the basic CH-47D supported an adequate evaluation of the CH-47F. The only LFT&E concern is that accidental damage done to the ground test vehicle may preclude dynamic testing of the fire suppression system, fuselage tunnel flight controls system, and the main rotor blades.





All of the Army's CH-47 Chinooks are to be upgraded to the new CH-47F models by 2018 as the result of a partnership between the service and Boeing, the helicopter's manufacturer. Under the plan, the Army will buy 55 new CH-47F models, have 397 helicopters remanufactured into CH-47Fs, and have 61 remanufactured to the CH47G used by Special Forces units. Total procurement costs through 2018 under the plan would amount to $11.4 billion. CH-47 helicopters that are remanufactured are to be rebuilt from the ground up and receive recapitalized depot-level repair components that are nearly "zero hour" or new. The aircraft themselves are to receive new airframes.

By October 2005 Boeing had started production for the new CH-47F Chinook heavy-transport helicopter as part of the U.S. Army Cargo Helicopter modernization program. The inclusion of the new airframe in the remanufacture program will greatly reduce required maintenance on the existing Chinook airframes, which in some cases are almost 40 years old.

The new airframe is constructed utilizing advanced manufacturing techniques where large single piece components replace built-up sheet metal structures and aluminum honeycomb formers. These components reduce operating and support costs while improving the structural integrity of the aircraft, extending the overall useful life of each Chinook.

Structural improvements include air transportability modifications, which reduce time necessary to prepare the aircraft for cargo transport and advanced corrosion protection. In addition, the implementation of lean manufacturing processes on the factory floor and use of employee involvement teams have reduced manufacturing costs and improved production efficiency.

Utilizing today's technology expands the range of improvements in this aircraft. This configuration with the Army's Common Aviation Architecture System cockpit makes the Chinook fully compliant with digital battlefield requirements and allows for greater and easier growth in systems.



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