Unit-equipped Air Force Reserve Command C-141 units received "glass cockpit" aircraft in which old dials and knobs have been replaced with computerized touchscreens and digital readouts. A team from the logistics center's C-141 System Program Office, in a partnership program with Raytheon E-Systems of Waco, Texas, completed the work. Modifications included an all-weather flight control system, the Global Positioning System, a fuel-quantity indicating system and the Airlift Defensive System. The program was finished by August 1999.
The first of 64 modified C-141B's rolled out as a C-141C model during a ceremony on 31 October 1997. Maj. Gen. James E. Sherrard III, AFRC vice commander, accepted the aircraft from Maj. Gen. Rondal H. Smith, Warner Robins Air Logistics Center commander. The aircraft belonged to the Reserve's 452nd Air Mobility Wing, March Air Reserve Base, CA. The 452nd Air Mobility Wing, March Air Reserve Base, Calif., is the first unit, active or Reserve to receive the C-141C "glass cockpit" modified Starlifter. The 452nd undertook responsibility for operational testing and evaluation and for developing initial cadre aircrew training. In addition to the 452nd AMW, the Reserve's 445th Airlift Wing, Wright-Patterson AFB, Ohio, and 459th AW, Andrews AFB, Md., received the modified aircraft. Air National Guard units at Jackson, Miss., and Memphis, Tenn., are also received the C-141C's.
C-141 modifications aim to preserve the remaining force by reliability and maintainability improvements and capability improvements necessary for effective use through 2006. Thirteen aircraft received additional SOLL II upgrades under the Special Operations Forces Improvement program. Sixty-three aircraft in the current C-141 fleet underwent major modification. Each received the All Weather Flight Control System (AWFCS) consisting of a digital autopilot, advanced avionics display, and Ground Collision Avoidance System (GCAS). Other major improvements include a Defensive Systems (DS), Fuel Quantity Indicating System, and GPS modifications. As a general rule, these 63 aircraft are the "youngest" (fewest equivalent damage hours) in the fleet and will carry the weapon system through programmed retirement in 2006.
- All Weather Flight Control System (AWFCS) The AWFCS modification is necessitated to alleviate reliability and maintainability problems being experienced due to the aging (or rather aged) avionics systems on the C-141. A high-tech 3-for-1 modification, the AWFCS would replace the existing 1960s C-141 autopilot system with a digital "glass cockpit" autopilot system. The AWFCS also includes the Automated Flight Control System (AFCS), a Control Display Subsystem (CDS), and a congressionally mandated Ground Collision Avoidance System (GCAS). The experts believed that the AWFCS would improve flight safety, as well as increasing reliability, supportability, and maintainability, since the old system was obsolete and becoming unsupportable because of a shortage of replacement parts. The system's functionality includes: autopilot, autothrottle, yaw damping, ground collision warning, primary flight instrument display, and warning display. LRUs installed by this modification (4 6x8" AMLCD Display Units (DUs), 2 Automatic Flight Control Processors (AFCPs), 2 Display Processor Units (DPUs), and 2 Display Avionics Management Units) replace approximately 19 antiquated LRUs, Indicators, and Controls. Additionally, a new Ground Collision Avoidance System (GCAS) and Multi-function Standby Airspeed/Attitude/Altitude Indicator (w/independant airdata source) are installed during this modification. Originally, plans called for the AWFCS to be a separate modification to be installed on 63 C-141B aircraft (45 Air Force Reserve and 18 Air National Guard). Ultimately, the decision was made to make it a part of the Mod Block program, a strategy designed to utilize the time during which a C-141 was already in-depot for modification or repair. As a result, whenever an aircraft arrived for modification or repair all four systems included in the Mod Block -- the AWFCS, the Global Positioning System Enhanced Navigation Systems (GPSENS), the Air Defensive System, and the Fuel Quantity Indication System -- would be installed at the same time.
- GPS Enhanced Navigation System (GPSENS) GPSENS integrates into the AWFCS aircraft to provide GPS based navigation and centralized and consolodated control of the majority of aircraft communication and navigation equipment via 3 Multifunction Control Display Units and 2 Navigational Processors. The Fuel Saving Advisory System (FSAS) LRUs are removed and their functionality is rehosted within the Nav Processors. The GPSENS, TCTO 1C-141-541, was designed to integrate with the new autopilot replacement system, AWFCS, and was part of the Mod Block program. Its installation would provide worldwide three-dimensional positioning/navigation capability to C-141 aircraft. Indeed, the experts estimated that the GPS would provide aircrews with the most accurate positioning, velocity, and timing information available today. Accuracy within: 22 meter[s] horizontally. 27.7 meters vertically. 90 nanoseconds. Plans called for the modification of the same 63 C-141 aircraft to included two navigation processors, three multi-functional control display units, one data loader/receptacle, and one GPS antenna. A "super kit" was designed to aid in installing the GPSENS and AWFCS simultaneously.
- Digital Fuel Quantity Indication System (FQIS) The new digital FQIS provides a display of fuel quantity in the same manner as the old analog system - one indicator for each tank and a totalizer to sum each individual tank reading (except in a digital format vs the analog dial). The indicators used in the old system gave incorrect readings and proved consistently unreliable. The new system replaces the present analog quantity gauging system with a new digital system. The new system provides a dependable gauge of the individual tank's capacity as well as an accurate reading of the volume of fuel carried by the aircraft. All components and wiring of the old system are replaced when the new system is installed. A complete aircraft kit consists of 11 Digital Fuel Qauntity Indicators (one part number which is interchangeable for all tank indicator positions and totalizer), 68 Full Height Compensated (FHC) Fuel Probes, and associated wiring. BIT capabilities facilitate ease of maintenance and trouble shooting.
- Airlift Defensive System (ADS) ADS provides C-141 aircraft with a common self-protection capability against shoulder fired man portable Surface-to-Air Missile threat. The C-141 Airlift Defensive System (ADS) program called for the installation of Group A hardwiring and Group B subsystems including the AAR-47 and the advanced ALE-47 flare dispenser system on 11 C-141B and 63 C-141C aircraft. The ADS would provide the aircraft with a common self-protection capability against the man portable infrared surface-to-air missile threat. Managers in the C-141 Program Management Branch (LJLM) oversaw the Group A, while those in Electronic Warfare Branch (LNXB) and Defensive Systems Branch (LNXC) administered the AAR-47 and the ALE-47 respectively. Phase I of the C-141 Airlift Defensive System had begun with a sole source contract to Rockwell, Shreveport, Louisiana, in February 1995, because of the important and immediate need in Bosnia. As a result, 27 C-141 aircraft were modified at that time with ADS. In August 1996, as part of Phase II, the Group A contract for the C-141 ADS went to Manufacturing Technology, Inc., (MTI), a small business in Fort Walton, Florida. Center LJP personnel received the Group A First Article Kit from MTI in January 1997. The production kits began arriving in June 1997, with installation beginning in July 1997. Furthermore, all of the Group B deliveries also occurred on time. Plans called for the ADS installation to be finished by June 1999, with a total of 47 aircraft completed as part of Phase II. These installations would be done at both Robins and at Raytheon E-Systems, Waco, Texas, the contractor. The end result of Phase I and Phase II would be that the Air Mobility Command (AMC) would then have 74 ADS-modified aircraft.
- L-Band Satcom System Operating on the Inmarsat and GPS satellites with interconnection to international telex, fax and switched data networks, the L-Band Satcom system provides automatic (and manual) data reporting and message transfer of position reports, performance data and operational messages on a 24 hour global basis. Coverage is provided from sea level to 55,000 feet from 70 degrees north to 70 degrees south.
- Interim GPS Provisions The C-141 aircraft is equipped with provisions to allow the use of hand-held GPS equipment. Power and antenna access plugs are located at the aft end of the center pedestal. Hand-held GPS units in use consist of the Precise Lightweight GPS Receiver (PLGR) and the Bendix-King KLX-100 (Comm functions not allowed for on-aircraft use).
- Traffic Collision Avoidance System (TCAS) Current plans include the installation of a TCAS on the C-141 aircraft.
In the short-term, the Air Force concentrated on repairing those aircraft with remaining service life. Major modifications include a new autopilot and All Weather Landing System (AWLS), Global Positioning System (GPS), Airlift Defensive System (ADS), and more accurate fuel quantity indicators. These modifications were required to maintain the C-141 as an effective weapon system. To minimize unnecessary costs, the youngest 63 aircraft, which are all in the ARC, received these upgrades and are termed the "ARC Core 63." The Air Force plans to retire active duty C-141s by FY03 and Unit Equipped (UE) ARC aircraft by FY06.
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