The information in the report below was generously provided by Dr. William Head, who is the chief historian at Warner-Robins. Due to the conversion of a Word Perfect document to HTML via Microsoft Word (whew!!), the links at the bottom of the page in footnotes don't seem to function 100%. Sorry about that. You can contact Dr. Head at firstname.lastname@example.org
In FY02, the C-141A/B/C Starlifter aircraft, the aging “workhorse” of the Air Force, continued to carry out a multi-various number and kind of exigencies by airlifting combat forces over long distances, delivering equipment by air or airdrop, and transporting the sick and wounded from hostile zones to medical accommodations. Lockheed engineers built the C-141A between 1963 and 1968. Following the Arab-Israeli conflict of 1973, it became clear that the C-141A lacked capacity and an aerial refueling capability. To this end, between 1978 and 1982, Lockheed and Air Force planners and workers “stretched” the fuselage increasing its cargo capacity by one-third and added an in-flight refueling capacity. The development of the “stretched” B-model had “the same overall effect as increasing the number of aircraft by 30 percent.” Over the years, the C-141 force amassed nearly nine million flying hours performing training, worldwide airlift, combat support, and humanitarian aid.
Recent Upgrades and Significant Events
In FY02, the C-141 carried on its
airlift legacy, but its days were numbered. Air Force officials had long
since decided to replace all grand old ladies with the new C-17 by 2006.
Lockheed had originally built 276 C-141As. During FY01, personnel
retired twenty-nine C-141s to the Aerospace Maintenance and Regeneration Center
(AMARC), Davis-Monthan AFB,
Traffic Alert and Collision Avoidance System (TCAS)/Terrain Awareness and Warning System (TAWS)
While developers made TCAS and TAWS to be two separate avionics systems, Air Force technicians discovered that they operated well together on the C-141 aircraft. Designers created TCAS to reduce the potential for midair collisions. They created TCAS to operate independently from, and yet supplement, the air traffic control (ATC) system. If the system determined that an aircraft was a threat, TCAS provided the aircrew with both aural and visual data to avoid midair collisions. By the end of FY02, Center C-141 SPO employees had installed the TCAS II, the most current version of TCAS, on all the remaining C-141 aircraft.
Designers made TAWS to help prevent accidents caused by Controlled Flight into Terrain (CFIT) or severe wind shear effects. They designed the system to achieve this objective by accepting a variety of aircraft parameters as inputs, applying alerting algorithms, and providing the flight crew with aural alert messages, visual annunciations, and displays in the event that the dynamic boundaries of any alerting envelope were exceeded. System components included: Aircraft Sensors and other systems providing input signals, the Enhanced Ground Proximity Warning Computer (EGPWC), Flight Deck Audio Systems (Speaker and Interphone), Alert Lamps and/or digital outputs to EFIS [Electronic Flight Instrument System] and EICAS [Engine Indication and Crew Alert System] displays (for alert and system status messages), EFIS Navigation Displays (ND) or Weather Radar Indicator for display of terrain, and Switching Relay(s) when required for switching display inputs from weather display to terrain display.
System developers also designed TAWS to be completely compatible with normal multi- engine transport aircraft operations. They intended that unwanted alerts would be very rare if the flight crew maintained situational awareness with respect to the terrain and if they followed correct avoidance procedures for any significant wind shear activity. Moreover, they integrated several main alerting functional areas into the EGPWC which acted as a single Line Replaceable Unit (LRU). Except for the basic Ground Proximity Warning System (GPWS), crew members selected each function by using a pin. The functional areas included: Basic Ground Proximity Warning, Altitude Awareness Call-outs, Excessive Bank Angle Alert, Windshear Detection and Alerting, Terrain Clearance Floor, and Enhanced features, Terrain Awareness Alerting and Warning, as well as optional display of this information. Pilots obtained the terrain display by providing GPS time and location data to the TAWS processor. The processor took that information and employed it to access and display the terrain features from a worldwide terrain database stored in the TAWS processor.
Since FY98, the C-141 TCAS/TAWS
program has been a Secretary of Defense (SECDEF) mandated modification that
qualified the C-141 to meet current International Civil Aviation Organization (ICAO)
Navigational Safety requirements for passenger-carrying aircraft.
Officials expected it to provide aircrews with the situational awareness
necessary to avoid midair collisions and CFIT. As such, Center C-141
personnel proceeded with the procurement of C-141 TCAS/TAWS LRUs
from Original Equipment Managers (OEMs) through an Indefinite Delivery
Indefinite Quantity (IDIQ) contract managed by the Global Air Traffic
Management (GATM) SPO at Hanscom AFB,
By the end of FY02, the 82 aircraft scheduled for TCAS/TAWS and TCAS II modifications had been completed. The C-141 workforce had installed TCAS/TAWS on 53 C-141C models and TCAS II on 19 C-141Bs. The workforce completed work on the last modification aircraft during PDM on 28 September 2002. In October 2002, personnel also incorporated the Change 7 Software Upgrade to improve safety and compatibility with international airspace requirements.
Global Positioning System Enhanced Navigation System (GPSENS) Program
Another important upgrade was the Global Positioning System Enhanced Navigation System (GPSENS) and its incorporation into the C-141 aircraft. The Navigational Standard Radar (NAVSTAR) GPS program began in 1980 as a tri-service modification project consisting of three major subsystems: the space segment, operations and control segment, and user equipment (UE) segment. They operated together to provide worldwide navigation capabilities to numerous Army, Navy (Marine), and Air Force ground and airborne platforms. Indeed, engineers fashioned NAVSTAR GPS to act as a space-based high-quality global radio, navigation, and time-transfer system that provided precise three-dimensional position, velocity, and time information to users. From the outset, military planners determined to employ GPS to streamline navigational requirements and reduce communications confusion thus reducing flight time and fuel consumption. Throughout its 22-year life cycle GPS has successfully operated in combat successfully coordinating with bombing and other weapons delivery systems.
By the late 1990s, systems developers had created the more modern GPSENS to provide new navigational modes for the C-141aircraft. This included a combination of the GPS/Inertial Navigation System (INS) and an independent GPS, and independent INS. The GPSENS afforded superior operator cockpit management of the navigation and communication systems. Systems experts used commercial GPS units pursuant to a June 1994 directive from Headquarters (HQ) Air Mobility Command Commander (HQ AMC/CC), due to the lower cost and accelerated delivery schedules which the commercial cards (internal circuit boards) provided. Center and Command personnel determined that under IAW FY97-02 Programmed Objective Memorandum (POM) the program cost would be $23.6 million in FY96, $18.7 million in FY97, $7.5 million in FY98, and $4.0 million in FY99--for a total of $53.8 million.
On 24 February 1995, Center C-141
and Contracting (WR-ALC/PK) officials co-chaired an Acquisition Strategy
Roundtable Panel. They decided to fully integrate GPS on the
C-141B. Thus, on 30 August 1995, they awarded Engineering Change Proposal
(ECP) contract modification F09603-93-C-0322-P00021 to Chrysler Technologies
Airborne Systems (CTAS),
In spite of some early road blocks, Center C-141 management and employees worked very hard on this program. In 1997, Congress mandated that GPSENS with GPS capabilities be incorporated into all civilian and military Flight Management Systems (FMSs). With this tasking before them, LJ personnel geared up to modify 63 C-141C models owned by AMC but used by ANG and AFRC operational units. Over the next five years this process successfully unfolded.
The GPSENS upgrade added a Navigation Processor (NP)-based FMS which replaced the Fuel Savings Advisory System (FSAS). Technicians also integrated the new FMS into the All Weather Flight Control System (AWFCS). The GPSENS dual system provided 100 percent redundancy for FMS operations affording an integrated or independent navigational solution under all circumstances. The new system also operated coupled to, or uncoupled from, the autopilot providing a Lateral and Vertical Guidance capability. In addition, it furnished the C-141C with a FMS airdrop capacity and FMS Non-Precision Approach ability.
The setup allowed GPSENS commands
to be input through a Multi-Function Control Display Unit (MFCDU) that system
designers created so it would be compatible with the Night Vision Imaging
System (NVIS). Finally, it employed a Digital Navigational Database (DND)
furnished by Honeywell Defense Avionics Systems,
On 27 June 2000, the LJ workforce initiated the installation process, concurrent with TCAS/TAWS modifications. After initial installations, employees tested C-141 GPSENS Take Off and Landing Data (TOLD) and OFP Block Cycle #1 software upgrades together at the RSC C-141 Simulation Laboratory. In October, they conducted the first regression test of the new software version. In January 2001, test experts carried out successful flight tests on the new software. They completed regression tests in conjunction with airdrop tests from 9-13 April 2001. On 19 June, leaders at AMC gave their approval for the operational use of GPSENS which provided C-141C s with airdrop and automated TOLD capabilities. In June and July, the workforce completed tests and published the technical data. Concurrently, they began fleet software installation on 25 June and completed it on 30 August 2001. By November 2002, LJ personnel had completed all 63 aircraft in conjunction with Programmed Depot Maintenance at Robins AFB; the final aircraft being C-141C tail number (T/N) 65-9414.
Other Modernization Efforts
In FY02, LJ technical experts (WR-ALC/LJLM) persevered in their efforts to sustain the reliability and maintainability (R&M) of the C-141C’s advanced avionics. While FY02 witnessed the continued release of avionics Operational Flight Program (OFP) Block Cycle #1 following the GPSENS TOLD and airdrop releases. Even as this cycle progressed, on 1 June 2002, personnel began preparing to field OFP Block Cycle #2. They also began precursory work on software changes for OFP Block Cycle #3, which was tentatively scheduled for fielding in early 2003. The OFP Block Cycle #2 contained several changes, including alterations to the AWFCS and GPSENS LRU OFPs. Programmers succeeded in combining the GPSENS navigation processor into both the aircraft and aircraft simulator OFPs. This allowed concurrent fielding of both OFPs, eliminating any delays in crew training. This saved the Air Force $500,000 in development costs. The OFP Block Cycle #2 also contained several changes designed to enhance AWFCS and GPSENS LRU maintenance and facilitate air crew usage. Members of the Avionics User Working Group (AUWG) recommended all these modifications.
Throughout recent years, LJ has held meetings (usually annually) of the AUWG, which officials formed from unit-level air crews and maintainers. In this form analysts received feed back on software changes and other issues. Based on these very candid gatherings LJ software experts determined which software alterations should have priority. At the same time, group representatives participated in all design reviews held by the contractor to ensure that software changes met the intent of the original requested modifications. This process has guaranteed direct operational personnel involvement in the sustainment of the C-141C.
As the fiscal year ended, even though they all knew the C-141s would soon be only museum fixtures, the Center’s C-141 maintainers continued to care for their beloved old “trash haulers” as if they were brand new–with dedication and concern.
An Emergency in
The next topic provides an example
of why procedures are in place when preparing and aircraft for take off and why
the vast majority of Air Force missions are undertaken with little difficulty
and seem to most to be very routine. Indeed, sometimes the average person
forgets just how uncertain flight can be. Only the expertise of
maintainers at Centers like WR-ALC and the careful inspection of each aircraft
prior to each sortie prevents disaster. On 20
December 2001, an ANG C-141C T/N 61-2778 at Memphis ANG Center, Memphis
International Airport (IAP), Tennessee, began preparations to rotate withe one of four other C-141Cs then flying supply missions
from Ramstein Air Base, Germany to U.S. Air Force and
Navy installations in Saudi Arabia, Turkey and elsewhere in the Persian Gulf as
part of the European-Strategic Intra-theater Deployment in ancillary support of
Operation Enduring Freedom (OEF). As the local ground crew in
Initially, uncertain about the
cause of the mishap, Tennessee ANG officials halted operations at Memphis IAP
and contacted AMC management at Scott AFB,
The only remaining question facing officials was what to do with the wrecked aircraft. After a thorough examination of the aircraft, LJ, ANG, and AMC leaders and experts conferred. As Alford put it, “it did not take rocket science to determine we did not want to pay what it would take to repair the aircraft, when it was scheduled for retirement in a couple of years anyway.” As he noted, “we would have made it airworthy just in time to fly it to the bone yard.” Ultimately, those involved all agreed to scrap the old bird. Over the following weeks several workers removed usable parts to act as replacement items for the remaining C-141Cs.
As they always seem to do, Center
personnel had taken a difficult situation and done their best to make the best
of it. Only three months after the 11 September 2001 (9/11) terror
attacks maintainers in
The last topic deals with one of
the Air Force’s most hallowed aircraft C-141B T/N 66-0177, better known as the
“Hanoi Taxi.” On 12 February 1973, this Starlifter
became the first
Late in FY01, leaders of the 445th Airlift Wing (445AW), Wright-Patterson AFB, Ohio, the using unit, knowing that number 66-0177 would be retired in late 2004, asked their superiors at HQ AFRC for permission to repaint their plane the 1970s gray and white paint scheme during its final programmed depot maintenance (PDM) at WR-ALC in FY02. Not only did AFRC officials grant permission but the also agreed to fund the repaint. Center C-141 SPO workers took great care with the “Hanoi Taxi” during its fourth quarter FY02 PDM. Even as they completed their work for the formal final roll out ceremonies, a special pilot arrived with 66-0177's regular crew to fly her home for the last time.
Major General Edward J. Mechenbier was the special pilot. Then serving as
Mobilization Assistant to the AFMC Commander, Lester Lyles, Mechenbier
was one of those young POWs who came home on the “Hanoi Taxi” from the terrible
prison he and his fellow POWs named the “Hanoi Hilton.” In June 1967,
then Lieutenant Mechenbier, stationed at Da Nang Air Base (AB),
In his farewell address Mechenbier told the audience “it’s great to be doing
something positive, but more importantly this airplane is a symbol of freedom
of the spirit. Flying it is a tribute not only to me and the POWs, but to
everybody that’s brought this together.” At 1018 hours, General Mechenbier lifted the “Hanoi Taxi” gently off the Robins
AFB tarmac circled the field, tipped his wing in salute and headed home to
Clearly, this program remained a very important sustainment project in FY02, especially since C-141 airframes are over 35-40 years old. Indeed, most Air Force and DoD officials and aviation experts never expected the Starlifter to serve past the early 1990s, but the protracted deployment of the C-17 Globemaster III aircraft made it necessary to continue to fly ever-increasing numbers of strategic airlift missions using what General William Tunner once called the “work horse.” Even at the end of FY02, as most of the original 276 C-141s continued to be retired, the remainder continue to serve in the Air National Guard (ANG) and Air Force Reserve Command (AFRC). Throughout, the Center’s C-141 workforce has remained focused on its sustainment of the C-141s. Since 1978-1982, when they and Lockheed employees “stretched” the C-141A to make the B model to the 1990s when they replaced the Center Wing Box, this dedicated group has always gone the extra mile even for an aircraft soon to leave the inventory. They have continually upgraded and modernized the C-141s. Their record has been amazing! Now, as they continue to go into unexplored areas of aging aircraft sustainment, this dedication will be tested anew. But, if the TCAS/TAWS, GSPENS and other program prove anything it is that the more things change the more they stay the same. The Center’s C-141 workforce has always fulfilled their mission, and no doubt will in the future.
For historical background materials on the C-141, see William Head, Reworking the Workhorse: The C-141B Stretch Modification Program (Robins AFB, Georgia: WR-ALC, Office of History, 1984), [hereafter cited as Workhorse]; John W. Leland, “Air Mobility in Operations Desert Shield and Desert Storm,” found in William Head and Earl H. Tilford, Jr., eds., The Eagle In the Desert: Looking Back on U.S. Involvement in the Persian Gulf War (Westport, Connecticut: Greenwood/Praegar Press, 1996), pp. 67-105..
For details on the C-141A/B/C Starlifter Cargo Aircraft, see Hist (FOUO/PV/DL), WR-ALC, FY98, pp 146-155, 203-210 (U); Hist (FOUO/DL), WR-ALC, FY99, pp. 175-179 (U); Hist (FOUO/PV/DL), WR-ALC, FY00, pp 72-76 (U); Hist (FOUO/PV/DL), WR-ALC, FY01, pp 128-133, 136-140, 211 (U), 134-135 (FOUO).
Hist (FOUO/PV/DL), WR-ALC, FY01, pp. 128-129 (U).
Ibid., pp 129-130 (U).
Ibid., p 130 (U).
Ibid., p 132 (U).
For background information on Global Positioning System Enhanced Navigation System (GPSENS), see Hist (FOUO), WR-ALC, FY97 190-193 (U); Hist (FOUO/PV/DL), WR-ALC, FY 98, pp 206-208 (U); Hist (FOUO/PV/DL), WR-ALC, FY99, pp 249-252 (U); Hist (FOUO/PV/DL), WR-ALC, FY00, pp 174-176 (U); Hist (FOUO/PV/DL), WR-ALC, FY01, pp pp 133, 136-140 (U), 134-135 (FOUO). For details on GPS, see Hist (FOUO), WR-ALC, FY82, pp 257, 277 (U); Hist (S/DECL OADR), WR-ALC, FY83, p 220 (U); Hist (S/DECL OADR), WR-ALC, FY84, pp 304-306 (U); Hist (FOUO/PV), WR-ALC, FY86, pp 202-205 (U); Hist (S/DECL OADR), WR-ALC, FY87, pp 215-218, 267 (U); Hist (FOUO/PV), WR-ALC, FY89, pp 179-180 (U); Hist (FOUO/PV), FY90, pp 172-175 (U); Hist (FOUO), WR-ALC, FY91, pp 109-114 (U); Hist (FOUO/PV), WR-ALC, FY92, pp 124-130 (U); Hist (FOUO), WR-ALC, FY93, pp 2, 139, 161-169, 191, 223, 224, 231 (U); Hist (FOUO), WR-ALC, FY94, pp 126, 127, 129 (U), 128, 130 (FOUO); Hist (FOUO/PV), WR-ALC, FY95, pp 118, 121 (U), 119, 120 (FOUO).
Hist (FOUO), FY95, pp 118-119 (U); Hist (FOUO/PV/DL), WR-ALC, FY01, pp 133-134 (U).
Hist (FOUO), WR-ALC, FY95, p 121 (U)
Ibid.; E-mail (U), James P. Rivers, WR-ALC/LJLM to T Sgt. David J. Chupinsky, WR-ALC/HO, “Last C-141C model completed,” 14 Nov 02, [hereafter cited as C-141C E-mail], Sup Doc V-24.
Hist (FOUO/PV/DL), WR-ALC, FY01, p 137 (U); C-141C E-mail.
Hist (FOUO/PV/DL), WR-ALC, FY01, p 138 (U); C-141C E-mail.
Hist (FOUO/PV/DL), WR-ALc, FY01, pp 138-139 (U); C-141C E-mail.
E-mail (U), by Christopher C. Simmons, WR-ALC/LJLM to William Head, Ph.D., WR-ALC/HO, “Annual History,” 19 Mar 02, Sup Doc V-25.
Bullet Paper (U), by Russell Alford, WR-ALC/LJE, “Memphis Mishap – C-141C/61-2778,” 19 Mar 03, [hereafter cited as C-141 Bullet Paper], Sup Doc V-26; Article (U), by CNN News, “Air Force Grounds C-141 Jet Fleet,” 24 Dec 01, CNN.Com, http://cnn.allpolitics. printthis.clickability.com ; accessed on 18 Oct 02, [hereafter cited as CNN Article], Sup Doc V-27; Accident Rpt (U), by Aviation Safety Network, “Accident Description,” 21 Dec 01, http://aviation-safety.net/database/2001/011221-0.htm. , accessed on 18 Mar 03, [hereafter cited as Accident Rpt], Sup Doc V-28.
C-141 Bullet Paper; CNN Article; Accident Rpt.
C-141 Bullet Paper; CNN Article; Article (U), by Aviation News, “December 2001,” n.d., http://www.najaco.com/aviation/news/2001/december2001_2.htm , accessed on 18 Mar 03, Sup Doc V-29; E-mail (U), Russell Alford, WR-ALC/LJE to William Head, Ph.D., WR-ALC/HO, “Memphis Mishap,” 1621/18 Mar 03, [hereafter cited as Memphis Mishap E-mail #1], Sup Doc V-30.
C-141 Bullet Paper; CNN Article; Memphis Mishap E-mail #1; E-mail (U), Russell Alford, WR-ALC/LJE to William Head, Ph.D., WR-ALC/HO, “Memphis Mishap,” 1644/18 Mar 03, Sup Doc V-31.
Article (U), by Lanorris Askew, WR-ALC/PA, “‘Hanoi Taxi’ departs Robins after final maintenance stop,” 15 Oct 02, http://www.afmc-mil.wpafb.af.mil/HQ-AFMC/PA/news/archives /2002/oct/1021-02.htm, accessed on 18 Mar 03, [hereafter cited as “‘Hanoi Taxi’departs Robins”], Sup Doc V-32; Article, na, “‘Hanoi Taxi’ gets final makeover; returns to duty with 445th AW,” Citizen Airman (December 2002), http://www.afrc.af.mil/hq/citamn/dec02/hanoitaxi. html , accessed on 18 Mar 03, [hereafter cited as “‘Hanoi Taxi’ gets final make over”], Sup Doc V-33.
Askew, “‘Hanoi Taxi’ departs Robins;” “‘Hanoi Taxi’ gets final make over;” Article (U), by DoD Defense Prisoners of War/Missing In Action Office, “‘Hanoi Taxi’ returns to duty with a new look,” 7 Oct 02, http://www.dtic.mil/dpmo/newsre/2002/021007_afpn_hanoi_taxi. htm , accessed on 18 Mar 03, [hereafter cited as DoD Article], Sup Doc V-34.
Askew, “‘Hanoi Taxi’ departs Robins;” “‘Hanoi Taxi’ gets final make over;” DoD Article.