Aircraft profile: Short Brothers’ C-23 Sherpa
Far from being the most glamorous aircraft on the US inventory, the C-23 Sherpa has received several less than complimentary nicknames including ‘Boxcar with Wings’ and ‘Flying Winnebago’. Despite this, Tom Kaminski tells us it has proven itself to be a utilitarian workhorse and an important asset that has served both the US Army and the USAF during its career.
A line of C-23Bs await their next missions at Logistics Support Area Anaconda/Balad Air Base, Iraq, on July 7, 2005. US Army
BUILT BY Short Brothers from its model 330-200, the Sherpa was intended as an all-freight version of the regional airliner that was itself developed from the company’s earlier SC7 Skyvan. Commonly referred to as the Shorts 330, it retained the Skyvan’s 6.5ft (1.98m) square fuselage section, which was lengthened by 12ft 5in (3.78m). Although it also used the Skyvan’s outer wing panels, a new centre section was incorporated and the span was increased by nearly 12ft (3.66m).
Wearing the civil registration G-BSBH, the first prototype SD3-30 (SH3000) took to the air at the Short Brothers Belfast facility in Sydenham, Northern Ireland, on August 22, 1974, and the first production aircraft followed on December 15, 1975.
In July 1979, the US Air Force (USAF) began planning for the creation of European Distribution System (EDS); consisting of an automated logistics command, control, and communications (LOG C3) system; three spare parts warehouses, and a fleet of European Distribution System Aircraft (EDSA). The latter would be used to move spare parts and equipment between the US Air Forces Europe (USAFE) facilities and the three warehouses, which would be located at RAF Kemble in the United Kingdom, Zweibrücken Air Base, West Germany, and Torrejon Air Base, Spain.
The USAF issued a Request for Proposals (RFP) in 1982 that specified the requirements for an aircraft capable of carrying a 5,000lb (2,268kg) load up to 700nm (1,296km) and if required, operating at altitudes below 1,000ft (305m). The requirements included the capability to transport numerous different jet engines including the General Electric J79 and Pratt & Whitney F100 series. Candidate aircraft included the CASA 212-200, de Havilland Canada DHC-7 and the Shorts 330. Shorts announced a variant of its regional airliner, which was known as the 330-UTT (Utility Tactical Transport) in September 1982 and the second 3-30 (SH3001) was modified to become the 330 UTT prototype.
The 330 UTT’s 29ft- (8.84m) long cabin floor, which offered a capacity of 1,230cu ft (34.83m3), was strengthened to accommodate an 8,000lb (3,629kg) payload. It featured a forward cargo door on the port side of the forward fuselage along with two inward-opening paratroop doors at the rear of the cabin; it could carry 26 combat-equipped paratroops on removable side-facing seats. It also retained the airliner’s 500lb (227kg) capacity nose baggage compartment. Additionally, it was capable of operating at an increased maximum take-off weight. In response to the USAF RFP, Shorts offered a variant of the 330-UTT known as the Sherpa.
Sherpa 83-0512 (c/n SH.3100) at Edwards AFB, California, in August 1991. Assigned to the 412th Test Wing’s 445th Flight Test Squadron, it was the first of 18 C-23As delivered to the USAF and was originally allocated to the 608th Military Airlift Group’s 10th Military Airlift Squadron at Zweibrücken Air Base, West Germany. Retired to the Aerospace Maintenance and Regeneration Center (AMARC) outside Tucson, Arizona, on November 26, 1997, it was sold to Sky Way Enterprises, Kissimmee, Florida, as N118SW; the registration was cancelled in August 2012. Although similar in configuration to the 330-UTT, the Sherpa, like the earlier Skyvan, was equipped with a hydraulically-actuated rear cargo ramp. Capable of supporting loads up to 5,000lb (2,268kg) the ramp allowed as many as four LD3 containers to be loaded and unloaded. Another change between the Sherpa and the UTT was the removal of the cabin windows. A Sherpa prototype (c/n SH3094) first flew on December 23, 1982 wearing the civil registration G-BKWM.
The USAF ordered its first of 18 Sherpas to fulfil its EDSA requirement on March 2, 1984. In addition to the $54.5 million production contract, Shorts received a $96.2 million contract that covered contractor logistics support (CLS) over a period of ten years. The USAF also took options for 40 additional aircraft, which were assigned the Mission Design Series (MDS) designation C-23A. Powered by two PT6A-45R engines and wearing the civil registration G-BLLF, the first C-23A took to the air in Belfast, on August 6, 1984. Shorts delivered the initial pair to the USAF on November 2, 1984 and the last of the 18 aircraft was accepted on December 7, 1985. The EDS began initial operations in March 1985 with six aircraft and one warehouse at RAF Kemble (now known as Cotswold Airport) in England. The 'hub and spoke' route structure was intended to meet USAFE’s logistical requirements and reduce the delivery time for critical spare parts.
Initially assigned to the 332nd Airlift Division, the 10th Military Airlift Squadron (MAS) was activated at Zweibrücken, on November 9, 1983. It began operating the C-23A on January 15, 1984 and was reassigned to the 608th Military Airlift Group at Ramstein AB, Germany, on March 15, 1984. Operating under the call sign ‘Pokey’, the Sherpas flew regular daily logistics support flights throughout the USAFE area of responsibility in support of the EDS mission from November 1984 until formal operations ended on October 31, 1990. The last of 18 aircraft departed Europe for the US on November 14.
Three of the C-23As were subsequently relocated to Edwards AFB, where they were assigned to 412th Test Wing in support of the USAF Test Pilots School. Eight were transferred to the US Army and in March 1991 the remaining seven were transferred to the US Forest Service as excess property.
The latter aircraft, which had accumulated an average of just 4,500 flight hours, were modified by Western Aircraft Inc at Gowen Field in Boise, Idaho, to conduct aerial firefighting operations as support aircraft for the smokejumper mission. The modifications, which cost around $110,000 for each airframe, provided the aircraft with windows, cabin insulation and interior cabin linings, civil communications systems and other equipment associated with the mission. Although capable of delivering 10-12 smokejumpers, eight are typically carried. Four of the aircraft entered service with the US Forest Service (USFS) but the other three were passed on to the Bureau of Land Management (BLM). In 1991, three of the USFS C-23As and one BLM aircraft entered service. The remaining three C-23As became operational in 1992. Although the BLM examples have since been retired, the USFS continues to operate its four C-23As. Two of the former BLM Sherpas are now operated by commercial operators, the third retired airframe is used as a ground trainer by the USFS in Redmond, Oregon.
The USDA Forest Service’s aircraft are primarily based in Redmond, Oregon, Redding California, and Missoula, Montana and the Redmond Air Center is the 'hub’ for the C-23A fleet. Located at Robert's Field Airport, the air center is assigned to Region 6 (Pacific Northwest) but it maintains the aircraft assigned to Region 1 (Montana, northern Idaho) and Region 5 (California).
Following their retirement by the 412th Test Wing, the three USAF C-23As were placed in storage at Davis-Monthan AB, Arizona, in December 1997. Between May 1999 and October 2000 all three were removed from storage and sold to commercial operators. The US Army aircraft were dispersed to several Army Materiel Command (AMC) organizations including the Corpus Christi Army Depot and Army Aviation Test Center at Fort Rucker, Alabama. Operators then included the Rock Island Arsenal, Corpus Christi Army Depot, Aviation Technical Test Center (ATTC), Redstone Technical Test Center (RTTC), Chemical Biological Defense Command (CBDCOM) and the Communications Electronics Command (CECOM).
US Army C-23B serial 88-01864 (c/n SH.3204) deployed as part of Operation Desert Storm and carried markings to commemorate its service when visiting Buckley Air National Guard Base, Colorado, in May 1993. The Sherpa was originally assigned to the California Army National Guard’s 1106th Aviation Classification and Repair Activity Depot (AVCRAD) in Fresno. It was later assigned to Detachment 1, I Company, 185th Aviation (Theater Aviation). Bob Greby
Those aircraft assigned to ATTC, RTTC and CECOM were configured to support a variety of test duties. One of the JC-23As operated by the ATTC had been modified for use in support of the Program Executive Officer (PEO) Intelligence, Electronic Warfare and Sensors (PEO-IEW&S). Initially operated under the sponsorship of Program Manager, Airborne Reconnaissance Low (PM ARL) it acted as an Unmanned Aerial Vehicle (UAV) surrogate for payload testing of various sensor and target detection/recognition systems. While operated by the ATTC JC-23A serial 84-00466 was lost in a crash that occurred following a single engine failure on July 16, 1992. The Sherpa went down during a test mission four miles (6.4 km) north of Colquitt, Georgia, killing three personnel.
Although the Army still carries a single C-23A on its books, a further two had been considered to be supply support aircraft but these were removed from the inventory at the end of Fiscal 2012. All are located at Joint Base McGuire-Dix-Lakehurst, New Jersey, and assigned to the US Army Research Development and Engineering Command's Communications-Electronics Research, Development and Engineering Center (CERDEC) Flight Activity. The organization, which had previously been known as the CECOM (Communications Electronics Command) Flight Activity continues to utilize JC-23A serial 84-0464 for test duties and the Army Materiel Command provides oversight for the aircraft.
The US Army’s first examples of the Shorts 330 actually entered service in 1985 when four standard SD3-30 airliners were acquired. The aircraft had previously been operated by the California-based Golden West Airlines, which went bankrupt in April 1983, and had been in storage. After receiving modifications with Field Aviation in Calgary, Canada, the aircraft replaced several de Havilland Canada C-7A Caribous that supported operations at the US Army Kwajalein Atoll Kwajalein Missile Range in the south Pacific. Based at Bucholz Army Air Field on Kwajalein Atoll in the Republic of the Marshall Islands, the aircraft supported operations at several facilities that comprise the missile range.
Wearing army serial 85-25342, SD3-30 (c/n SH.3010) is one of the examples purchased by the US Army and operated from the Kwajalein Missile Range test site in the Republic of the Marshall Islands.Retaining their civil designations the SD3-30s were capable of carrying a mixed payload of cargo and up to 20 passengers and were equipped with military communications equipment and had military serial numbers assigned. For a short time in late 1987 and 1988 they were supplemented by two additional leased SD3-30s, which retained civil registrations N58MM (SH3060) and N59MM (SH3063). The SD3-30s were retired in 1992, when they were replaced by contractor operated de Havilland Canada DHC-7s. Following their return stateside, the aircraft were stored at the Naval Air Engineering Station (NAES) Lakehurst, New Jersey before being disposed of on the commercial market or sent to museums.
On October 26, 1988, the US Army purchased ten new Sherpas from Shorts, under the designation C-23B. They were intended as replacements for the few C-7As that remained in service with the Army National Guard. The Caribous were primarily used to ferry parts between the Guard's four Aviation Classification and Repair Activity Depots (AVCRAD) and its many aviation facilities. A further six examples were ordered in 1990. While similar in appearance to the USAF Sherpas, the C-23B combined the Shorts 330 (model SD3-30) airframe with the Shorts 360 (model SD3-60) wing and 1,424shp (1061kW) Pratt & Whitney Canada PT6A-65AR engines and five-blade Hartzell propellers. Additionally, the aircraft featured, advanced instrumentation, passenger windows, uprated landing gear and an air-operable, two-section cargo ramp/door. Whereas the upper section of the cargo ramp retracts inward and upward, the lower section, which is capable of accommodating a 600lb (272kg) capacity baggage pallet, drops down. With a maximum takeoff weight of the 25,700lb (11,657kg) the aircraft is capable of operating from unpaved runways and making short takeoff and landings (STOL). Used to transport cargo and personnel and for medevac duties the Sherpa can carry up to 7,280lb (3,302kg) of cargo or personnel.
Although production of the SD3-30 ended in 1992, when the final C-23B was delivered, the US Army still had a requirement for additional aircraft to equip several new fixed-wing units. In September 1993 the service issued a $113.6 million contract to Bombardier Aerospace, which purchased Short Brothers in October 1989, for 20 C-23B+ aircraft. Bombardier's West Virginia Air Center in Bridgeport created the C-23B+ by modifying SD3-60 airliners.
C-23As of the 10th MAS operating ‘Pokey’ daily flights around USAFE bases were always busy. This example, 84-0471 ‘Aviano’, is already taxiing for departure on the next leg of its daily journey around USAFE bases. It was one of eight Sherpas transferred to the US Army Materiel Command. Assigned the designation JC-23A, the aircraft supported numerous test programmes prior to its final retirement. Originally delivered to the USAF on October 10, 1985, the aircraft is now used as a training aid by the Enterprise State Community College at Enterprise Municipal Airport, Alabama.Developed from the model 3-30, the Shorts 3-60, featured the addition of a 3ft (.91m) fuselage ‘plug’ forward of the wing that increased seating to 36. Additionally, the 3-30’s twin tail was replaced with a completely redesigned conventional tail section. The prototype (G-ROOM) was first flown on June 1, 1981; a total of 164 SD3-60’s had been delivered when production ceased in 1991.
The C-23B+ was created by removing the 3-60's fuselage plug and the aft fuselage containing the airliner’s single vertical tail. In place of the tail structure, a new fuselage section, containing a cargo ramp and the SD3-30/C-23 twin vertical stabilizers was installed along with other modifications. The first flight of the C-23B+ took place in Bridgeport on December 12, 1995 and the Army National Guard accepted the aircraft from the Short Brothers division of Bombardier Corporation on June 25, 1996. Although the Army initially purchased 20 C-23B+ aircraft, a second batch of eight aircraft was ordered in November 1994 at a cost of $36 million. The initial batch of C-23Bs replaced C-7As assigned to the AVCRADs, but along with the C-23B+s, they were later organized to form four Theater Aviation Companies (TAC). Each company was responsible for eight Sherpas that, with two exceptions, were assigned to two aircraft detachments. The latter aircraft allowed the Army to replace six de Havilland Canada UV-18B Twin Otters that served with the Alaska Army National Guard’s 207th Aviation Company. The first of those aircraft was formally accepted at Bryant Army Airfield on October 17, 1996. The final C-23B+ delivery occurred in September 1998.
Residents from Anaktuvuk Pass, Alaska, assist soldiers from the 807th Medical Command unloading medical supplies from C-23C 88-01864 (c/n SH.3204) operated by ‘F’ Company, 207th Aviation (Theater Aviation), Alaska Army National Guard, in April 2011. USAFIn Alaska a total of eight aircraft were initially located at Fort Richardson. The complement was reduced to just seven aircraft as a result of a fleet reshuffle that followed the loss of C-23B+ serial 93-01336 on March 3, 2001. The Sherpa, which had been operated by the Florida Army National Guard, crashed near Unadilla, Georgia, killing 18 passengers and three crewmembers. This was the second Sherpa to be lost.
A single C-23B was also assigned to the US Army Research, Development and Engineering Command's Aviation Applied Technology Directorate (AATD) at Fort Eustis, Virginia’s Felker Army Airfield. It was later transferred to the Army National Guard.
The Theater Aviation Companies are tasked to provide intra-theater general aviation support. Capable of operating from unpaved runways and providing a short take-off and landing (STOL) capability, the Sherpa is equipped with self-contained ground handling equipment. When configured as a troop transport, it provides seating for 30 passengers on airline-type seats. It can carry up to 27 paratroops and a jumpmaster on side-facing seats and supports airborne operations via static-line or free-fall delivery. Aerial delivery of cargo can also be accomplished via the ramp. An integral winch allows non-powered vehicles or wheeled cargo to be loaded. Alternately, when operating in the medical evacuation (medevac) role 15 litters and three attendants or 18 litters and two attendants can be accommodated. Although the C-23s are ‘war-traced’ to Theater Aviation Brigades, the day-to-day scheduling for operations in the continental United States (CONUS) is handled by the Operational Support Airlift Agency (OSAA) at Davison Army Airfield, Fort Belvoir, Virginia. The aircraft typically fly an average of 35 hours monthly.
Differences between the C-23B and C-23B+ included the inclusion of two Universal Avionics Systems Corporation’s UNS-1K flight management system (FMS) in the former and one in the latter, which was already equipped with a single UNS-1B. The C-23B/B+ fleet, was upgraded through the installation of the UNS-1K as part of Avionics System Cockpit Upgrade (ASCU) and Global Air Traffic Management (GATM) projects.
In May 2002 the USAF’s Air Force Materiel Command approved the MDS designation change for all C-23B and C-23B+ aircraft to C-23C and the US Army Product Management Office (FW PMO) issued a memo re-designating the aircraft. However, because of confusion with regard to equipment and maintenance inspection intervals between the two versions, the FW PMO, Operational Support Airlift Agency (OSAA) and the logistic support contractor continued to refer the aircraft under their previous designations. For standardization purposes the aircraft were referred to as C-23Cs but this was only done to alleviate the need for separate pilot ratings for the two models. More recently the C-23C designation was finally adopted.
Logistical Support and upgrades
US Army C-23B serial 88-01864 (c/n SH.3204) deployed as part of Operation Desert Storm and carried markings to commemorate its service when visiting Buckley Air National Guard Base, Colorado, in May 1993. The Sherpa was originally assigned to the California Army National Guard’s 1106th Aviation Classification and Repair Activity Depot (AVCRAD) in Fresno. It was later assigned to Detachment 1, I Company, 185th Aviation (Theater Aviation). Bob GrebyAlthough Bombardier Defence Services Inc was initially responsible for providing contractor logistics support (CLS) for the C-23 fleet, in December 1994 Duncan Aviation, Incorporated, in Lincoln, Nebraska, was selected to provide life-cycle contractor support (LCCS). That association continued until 2005. Today, LCCS for the Sherpa fleet is provided by M7 Aerospace and its team, which includes L-3 Communications Vertex Aerospace. Located at San Antonio International Airport in Texas, M7 was awarded the C-23 LCCS contract in March 2005. With options the contract could be worth as much as $309.2 million over ten years. Now referred to as San Antonio Operations, M7 Aerospace is a subsidiary of Elbit Systems of America. Through its teaming arrangement, San Antonio Operations provides overall programme management, provides field teams to service aircraft away from their home bases, including some at overseas locations and manages engine, propeller and landing gear overhaul services. In addition, the company performs major inspections, maintenance and modifications as required.
M7 Aerospace delivered the first of four Sherpas upgraded under the Safety Avionics Modification (SAM) programme during 2010. SAM equipped the aircraft with the Rockwell Collins Pro Line 21 avionics system, which replaced the aircraft’s original analogue gauges with an electronic flight instrument system (EFIS), enhanced ground proximity warning system (EGPWS) terrain avoidance warning system (TAWS), traffic collision avoidance system (TCAS) and other modernized systems.
The system’s modern flight management capabilities and integrated systems both reduced pilot workload and complied with the latest Communications, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) and Global Air Traffic Management (GATM) requirements for world-wide navigation and deployment. The installation and subsequent flight test programme were carried out at M7 Aerospace’s Maintenance, Repair and Overhaul (MRO) facilities at the San Antonio International Airport, Texas. The programme was cancelled in 2010 after only four upgraded aircraft had been delivered. Initially referred to as the C-23C-1, the aircraft were subsequently assigned the designation C-23D.
JC-23A serial 84-0464 (c/n SH.3111) operated by the Communications-Electronics Research, Development and Engineering Center (CERDEC) Flight at Lakefront Airport, New Orleans, Louisiana on May 13, 2010. (US Army)In 2010 M7 Aerospace received the Army Aviation Systems Weapon Systems Award in recognition of work it performed to return several damaged C-23s to service. The four aircraft were damaged when a hangar collapsed at Balad AB, Iraq, during a violent wind storm in July 2009. Although the damage to two aircraft was so severe that the Army considered writing them off, the contractor developed repair plans and the final aircraft was repaired in December 2009. All four were subsequently flown back to San Antonio and underwent post-deployment reset inspections and repairs before being returned to their units. The company also received the Army Aviation Systems Weapon Systems Award for 2012 for outstanding logistic support to the Fixed Wing Project Management Office (FW-PMO) and C-23 programme during the 2011 coordination and completion of retrograde operations from Operation New Dawn in Iraq, and the C-23 Reset Program that overhauled the aircraft upon their return from southwest Asia.
All C-23 training is conducted by the Fixed Wing Army National Guard Aviation Training Center (FWAATS) in Bridgeport, West Virginia under the direction of the Operational Support Airlift Agency (OSAA). C-23 simulator training requirements are met in the Shorts simulator at Flight Safety International’s La Guardia Airport facility in Astoria, New York.
Deployed operationally to Southwest Asia for the first time during Operation Desert Shield in 1990 the Sherpas subsequently supported Operation Desert Storm in early 1991.The C-23B/B+s were sent back to support Operation Iraqi Freedom and were initially deployed to Kuwait in August 2003. The Sherpas later moved to Iraq in 2004 and accumulated approximately 47,000 flight hours over the following eight years operating primarily from Joint Base Balad. Heavily tasked during the conflict, operations included the movement of critical supplies such as blood, repair parts and ammunition. For safety, the crews adopted helicopter type tactics that called for the aircraft to be flown low and fast, often at altitudes of 100ft (30.5m) or lower and speeds of 200mph (322 km/h). In order to protect the aircraft while operating in the combat zone, 15 C-23B+s were provided with a deployable configuration that included a ballistic armour protection system (BAPS), aircraft survivability equipment (ASE) including the common missile warning system (CMWS), blue force tracker (BFT), microclimate cooling system (MCS) and night vision goggle (NVG) capable cockpits. Three additional C-23s are configured with the BFT but are not in the deployable configuration.
A paratrooper assigned to the 560th Battlefield Surveillance Brigade exits from a C-23C assigned to the Georgia Army National Guard’s ‘H’ Company, 171st Aviation (Theater Aviation) near Paulding Regional Airport in Dallas, Georgia, on February 5, 2013. Georgia ARNG
In June 2010, the OSAA accepted a new mission that resulted in the deployment of C-23s to Egypt's Sinai Peninsula in support of the Multi-national Force and Observers mission. The mission enforces the 1979 Camp David Peace Accords between Egypt and Israel. Since assuming the mission, Army National Guard units have deployed two Sherpas for rotational assignments in support of the observers as part of the 1st Support Brigade. The Theater Aviation Companies will continue to support this mission though the end of 2014.
As mentioned earlier, the majority of the C-23C/D fleet is operationally assigned to the theater aviation companies and are tasked by the Operational Support Airlift Agency (OSAA), which is also responsible for the standardization, training and safety. In addition to supporting the Theater Aviation Sustainment Maintenance Groups (TASMG) operations, the Sherpas continue to support special forces parachute training at locations including Fort Bragg, North Carolina, and test activities at various sites including the US Army Yuma Proving Ground in Arizona and the Natick Soldier Systems Center in Massachusetts.
The C-23’s recent homeland missions have included supporting operations associated with the Deepwater Horizon oil spill cleanup, which occurred in the Gulf of Mexico in April 2010. Most recently, C-23Cs from Connecticut, Florida, and Indiana and C-23Ds from Kentucky were pressed into service immediately after Hurricane Sandy struck the north-eastern US in October 2012. In the first week after the storm came ashore the OSAA assigned five missions to the Sherpas, which flew a total of 31.1 hours. The aircraft delivered 30 key personnel including a Federal Aviation Administration (FAA) airfield inspection team and Federal Emergency Management Agency (FEMA) team members along with 10,450lb (4,740kg) of equipment, supplies and food to stricken areas. Just days later, the Florida Army National Guard Sherpas were retired.
The Department of the Army released the C-23 Divestiture Plan Execution Order on February 11, 2011, which directed the Army National Guard to retire the first four Sherpas in Fiscal Year 2011. Under the plan the Army’s Sherpa fleet will be retired by December 31, 2014. The initial four aircraft were retired during Fiscal 2011 and in Fiscal 2012 two of the C-23As and four addition C-23Cs were retired. Eight additional aircraft will follow in Fiscal 2013. According to COL Michael Bobeck, the Chief of the Army National Guard’s Aviation and Safety Division, aircraft located in the Virgin Islands and Alaska as well as those supporting the ARNG TASMG depots will be amongst the last to be retired. Although the latest retirements left the Florida and Texas Army National Guard units without aircraft, OSAA is shuffling the remaining aircraft to ensure that the flight crews remain current as they prepare for a new mission. The initial retirements resulted in the Alaska Army National guard losing four of its aircraft.
Despite the approved divesture plan, as a result of the fiscal environment, the Army is understood to be looking at accelerating the Sherpa retirements by 15 months. The service determined that it could save $34 million by completing the retiring the aircraft by September 2013.
C-23C serial 94-00314 (SH.3428) departs Runway 16 at Quonset State Airport, North Kingstown, Rhode Island, in January 2013. Operated by ‘D’ Company, 192nd Aviation (Theater Aviation), Rhode Island Army National Guard, the Sherpa was the last of 28 Shorts 3-60 airliners (c/n SH.3689) to be converted to C-23B+ configuration.
The National Aeronautics and Space Administration (NASA) acquired several retired C-23Cs from the Army in January 2012. Included was serial 88-1864, which received the civil registration N430NA. Assigned to the Goddard Space Flight Center's Wallops Flight Facility in Chincoteague, Virginia, the aircraft underwent modifications to install scientific equipment in April 2012. The modifications included the installation of a spectrometer, atmospheric inlet probes connected to a gas analyzer for greenhouse gas measurements, forward and downward looking video and infrared cameras as well as several instrumentation racks and an a power system. The Sherpa subsequently departed Wallops for its first mission on May 16 to support the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) for the Jet Propulsion Laboratory. Primarily operating from Fairbanks International Airport, Alaska, the Sherpa flew missions that collected detailed measurements of greenhouse gases in the Alaskan Arctic. It returned to its home base on October 8, 2012 and following modifications departed again for Fairbanks on March 27, 2013.
Joint Cargo Aircraft
Launched in February 2004, the Future Cargo Aircraft (FCA) was intended as a replacement for the C-23 series. Funding for the new programme was made available when the Army cancelled Sikorsky Aircraft’s $14.6 billion RAH-66 Comanche helicopter. In February 2006, the FCA was merged with the USAF’s Light Cargo Aircraft (LCA) program becoming the Joint Cargo Aircraft (JCA). The Army had planned to acquire 54 C-27Js to replace the ageing Sherpa and reduce the workload placed on the heavily deployed CH-47 Chinook helicopter fleet. As a Sherpa replacement, the Spartan offered almost 3.5 times the lifting capacity and range and an 85kt improvement in top speed. Additionally, because it is pressurized it is capable of flying at higher altitudes than the Sherpa. In April 2009 the Secretary of Defense made the decision to assign the C-27Js and the Army’s direct support mission to the USAF. The Army aircraft were formally transferred to the USAF on September 29, 2010. Earlier in 2010 the Pentagon cut the planned C-27J buy from 78 aircraft to 38. The USAF’s 2012 decision to cancel the C-27J programme and divest the fleet of aircraft leaves the future of the direct support mission in limbo but has not altered the Sherpa retirement plans.
In addition to the SD 3-300 & C-23 aircraft a single Shorts SC7 Skyvan 3 was utilized by the Corpus Christi Army Depot from 1990 to 1993. Assigned the serial 90-00042 (SH1842), the aircraft, which had been acquired via the US government’s confiscated excess aircraft program (CEAP) had reportedly been seized from a drug smuggler in Louisiana during 1986. The Skyvan was later passed on to the National Aeronautics and Space Administration’s (NASA) Wallops Flight Center in Virginia, before being acquired by a commercial operator in Canada. First flown in January 1963, the Skyvan is powered by two 715 shp (533 kW) Garrett TPE331-2-201A turboprops.
Length: 58.04ft (17.69m)
Wing span: 74.84ft (22.81m)
Height overall: 16.41ft (5.00m)
Wheel track: 14ft (4.26 m)
Cabin length: 29.82ft (9.09m)
Cabin height/width: 6.46ft (1.97m)
Cargo door: 5.48ft x 4.63ft (1.67 x 1.41m)
Cabin volume: 1,246cu ft (35.28m3)
Cabin floor area: 185sq ft17.18m2)
Nose baggage compartment volume: 45cu ft (1.27m3)
Maximum takeoff weight: 25,600lb (11,612kg)
Maximum landing weight: 11,385kg (25,100lb)
Maximum payload: 7,280lb (3,302kg)
Maximum fuel load: 4,480lb (2,032kg)
Takeoff distance (at maximum takeoff weight): 1,850ft (564m)
Takeoff distance to clear 50ft (15m) obstacle: 2,630ft (802m)
Landing distance (at maximum landing weight) over 50ft (15m) obstacle: 1,920ft (586m)
Landing distance: 1,130ft (345 m)
Range (with max payload and no reserves): 446nm (827km)
Range with 5,110lb (2,318kg) payload: 1031nm (1912km)
Maximum rate of climb at sea level: 1,460ft/min (445m/min)
Service ceiling: 12,000ft (3,660m)
Maximum cruise speed at 10,000ft: (3,050m) 194kts (359km/h)
Normal cruise speed: 180 knots (333km/h)
Stalling speed, flaps and landing gear up: 97kts (179km/h)
Stalling speed at maximum landing weight, flaps and landing gear down: 78kts (145km/h)
Thanks to Mr. Gerry Cox FWPMO and Ms. Sofia Blesdoe Public Affairs Officer, Program Executive Office for Aviation at Redstone Arsenal, Alabama, and COL Michael Bobeck Chief, Aviation and Safety Division, Army National Guard.
Filed Under Military Aviation Features.
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