Role: Military transport aircraft are responsible for moving troops and cargo (including weapons, military equipment, fuel, and other goods) to an area of operational concern. Transport aircraft can have many specializations, creating a variety of logistical roles including: aerial refueling, airlift (strategic or tactical), air ambulance/medical evacuation, and air delivery (airdrops).
Aerial refueling is the transfer of fuel from the military transport aircraft (the tanker) to another (the receiver, usually aircraft such as fighters which have limited fuel capacity for longer ranges and loiter times). Aerial refueling plays an essential supporting role in military endeavors on both a strategic and tactical level. Developed in the midst of the Cold War, aerial refueling technology backed the Cold War doctrine of mutually assured destruction by continuously maintaining fleets, carrying nuclear armed warheads or conventional missiles, in the air for immediate retaliation against Russia or as a reserve should the USSR bomb their grounded fleets in airfields. On a tactical level, aerial refueling allows a wider range of coverage for forces, removes fuel/speed balance concerns, and allows less aircraft units needed for a given mission.
There are two dominant refueling methods currently used: the probe-and-drogue and the flying boom. The probe-and-drogue system has been around in a primitive version since 1948 and was first developed by Cobham plc’s subsidiary Flight Refuelling Ltd. The tankers are equipped with the “drogue”, a basket-shaped receptacle containing a flexible and retractable hose attached to a hose drum unit (HDU). The receivers have the probe. The two aircraft must get in line astern formation, with the receiver ideally behind and below the tanker. Once the probe correctly meets with the drogue, the hose recedes back into the drum set where fuel is stored and transfer can begin. Aircraft can be easily fitted with probe-and-drogue systems and multiple fueling points can be installed, making refueling more than one aircraft feasible. However, this system is also susceptible to weather conditions and turbulence which can interfere with proper alignment of the probe and drogue. Additionally, the relatively slow fuel transfer rate of the hose in this system (1500-4500 pounds per minute) can make for a prolonged fueling time. The second method is the flying boom system. Originally developed by Boeing in the late 1940s, the flying boom system entails a rigid pipe attached to the tanker and a compatible receptacle on the receiver aircraft. The boom can transfer up to 6500 pounds per minute. However, the system requires a dedicated boom operator and can only refuel one aircraft at a time.
Airlift is a general military term used to describe the transport of goods and personnel within a theater of operations (tactical) or long-distances across theaters (strategic). Air ambulance/medical evacuation can be used to describe the transport of hospital equipment into a warzone or the evacuation of injured parties to an area of relief. Air delivery, or air drops, is the delivery of goods (humanitarian supplies, weapons, etc.) from the aircraft to a ground base usually via parachute. Airdrops require skills and expertise and are categorized as low-velocity (delicate items requiring a slow fall using parachutes), high-velocity (parachutes used only near the end) and low altitude parachute extraction system (LAPES, where the aircraft drops the cargo without a parachute but extremely close to the ground), and free fall (no parachutes for sturdy goods). An airdrop may be pulled from the aircraft with a parachute (extraction method), slid out by tilting the aircraft (gravity method), or pushed out (door bundle method) by the Loadmaster (the aircrew member in charge of cargo).
Models in Service:
United States Air Force (USAF), United States Army (USA), United States Marine Corps (USMC), United States Coast Guard, United States Navy (USN)
|NAME||BRANCH||VARIANTS||QUANTITY||MANUFACTURER||NOTES/CAPABILITIES IN BRIEF|
|C-2 Greyhound||USN||C-2A||34||Northrop Grumman||Engineered to support critical logistics missions conducted by the U.S. Navy’s Carrier Strike Group, the twin-engined Northrop Grumman C-2A cargo transport monoplane is specially designed to land on naval carriers. The C-2A Greyhound delivers mission-critical cargo, mail, and personnel to and from sea-based carriers and land-based shore bases. The C-2A Greyhound can carry an impressive payload of 10,000 pounds such as a load of jet engines. Powered by two Allison T56-A-425 turboprop engines providing 4,600 shaft horsepower each, the C-2A Greyhound cruises at 260 knots for a range exceeding 1,300 nautical miles at an operational ceiling of 30,000 feet. The service life of the proven Greyhound platform is 15,000 flight hours and 36,000 landings.|
|C-5 Galaxy||USAF||C-5A||23||Lockheed Martin||First entering service in 1970 in support of the Vietnam War, the Lockheed Martin C-5 Galaxy is the U.S. Air Force’s only strategic airlifter. The largest aircraft in the branch’s fleet, the C-5 Galaxy can transport a 285,000-pound payload consisting of 6 Mine Resistant Ambush Protected vehicles (MRAPs) or 5 rotorcraft—a payload twice that of any other airlifter. The colossal C-5 Galaxy is operated at the following Air Force Bases: 60th Air Mobility Wing, Travis AFB; 349th Air Mobility Wing, Travis AFB; 436th Airlift Wing, Dover AFB; 439th Airlift Wing, Westover, AFB; and 512th Airlift Wing, Dover AFB. Powered by four General Electric CF-80C2 turbofan engines with each providing 50,580 pounds of thrust, the nearly 250 feet long C-5 Galaxy cruises at Mach 0.77.|
|C-12 Huron||USAF||C-12C||16, 17||Beechcraft||The military variant of the Beech Model 200 Super King Air, the low-wing, T-tail C-12 Huron provides range clearance, medevac, VIP, personnel, and light cargo transportation for the U.S. Army, U.S. Air Force, U.S. Navy, and U.S. Marine Corps. Powered by dual Pratt & Whitney PT6A-41/41/60A turboprop engines, the C-12 Huron can transport 3,500 pounds of cargo at 284 miles per hour at an operational ceiling of 25,000 feet. The aircraft climbs at a rate of 12 meters a second. The U.S. Air Force operates its Hurons with the 459th Airlift Squadron at Yokota Air Base, Japan, and Air Force Material Command at Holloman Air Force Base, New Mexico.|
|C-17 Globemaster III||USAF||C-17A||223||Boeing||With over 2 million flight hours completed, the four-engine, high-wing, T-Tailed Boeing C-17 Globemaster III is a proven military transport platform. Powered by four Pratt & Whitney PW2040 series engines, the C-17 Globemaster III can carry a payload of 160,000 pounds for a range of 2,400 nautical miles. The U.S. Air Force’s fleet of 223 Globemasters are deployed at the following 12 bases: Joint Base Lewis-McChord, Washington; Charleston AFB, South Carolina; McGuire FB, New Jersey; March Air Reserve Base, California; Joint Base Pearl Harbor-Hickam, Hawaii; Joint Base Elmendorf-Richardson, Alaska; Altus AFB, Oklahoma; Dover AFB, Delaware; Travis AFB, California; Wright-Patterson AFB, Ohio; Stewart Air National Guard Base, New York; and the Air National Guard Base at Jackson, Mississippi.|
|C-20||USAF||C-20B||5||Gulf-stream Aerospace||Based on the commercial C-20 Gulfstream business jet, the military variants are repurposed for transporting personnel (senior leadership and dignitaries) or for long-range, medium airlift logistics support. Depending on the variant, the C-20 is powered by two Rolls-Royce Limited Spey MK511-8 turbofan engines or two Rolls Royce Tay Mark 611-8 engines.|
|C-21||USAF||C-21A||47||Learjet||The military variant of the Learjet 35A business jet, the twin-engine Learjet C-21A provides cargo and passenger airlift for the U.S. Air Force. It is used by the Air National Guard as a low-cost training platform, giving its personnel flying experience to eventually move on to pilot more complex weapon systems. Backed by dual Garrett TFE-731-2-2B turbofan engines providing 3,500 pounds of thrust each, the Learjet C-21A flies at speeds of 530 miles per hour (Mach 0.81) for a range of 2,306 miles at an operational ceiling of 45,000 feet. It is able to accommodate a payload of eight passengers and 3,153 pounds of cargo.|
|C-26 Metroliner||USAF||C-26B||11||M7 Aerospace||First deployed in 1989, the Fairchild C-26 Metroliner supports medevac, cargo, and passenger transport missions for the Air and Army National Guards. It supports the movement of key personnel to remote sites and is used to transport repair parts, maintenance teams, and accident investigation personnel. The C-26 Metroliner is the military variant of the commercial Fairchild Metroliner 23 light-lift aircraft. Powered by two Allied Signal/Garrett TPE-331-12UAR turboprop engines, the C-26 Metroliner flies at speeds of 246 knots for a range of 1,300 nautical miles at an operational ceiling of 25,000 feet. The U.S. Air Force operates its fleet of C-26 Metroliners with the 86th Airlift Wing at Ramstein Air Base in Germany and the 89th Airlift Wing at Joint Base Andrews in Maryland.|
|C-27J Spartan||USAF||C-27J||13||Alenia Aero-nautica||Premiering in 1997, the C-27J Spartan is a joint project between Lockheed Martin and Alenia Aeronautica, a subsidiary of Italian firm Finmeccanica. The joint venture team is dubbed Lockheed Matin Alenia Tactical Transport Systems (LMATTS), based in Marietta, Georgia. Backed by two Rolls-Royce AE 2100D3 turboshaft engines rated at 4,637-shp each, the C-27J Spartan can fly at speeds of 602 kilometers an hour for a range of 1,852 kilometers at an operational ceiling of 9,144 meters. In 2007, the U.S. Army and U.S. Air Force selected the C-27J Spartan as their joint cargo aircraft (JCA). The C-27J Spartan is designed with the same floor strength as the Lockheed Martin Hercules to accommodate a payload of armored military vehicles.|
|C-31 Troopship||USA||C-31A||2||Fokker||Since 1985, the U.S. Army’s Golden Knights Parachute Team has used the Fokker C-31A Troopship for its skydiving demonstrations. The U.S. Army’s two C-31A Troopships replaced the branch’s aging fleet of De Havilland Canada YC-7A Caribou aircraft that had been with the branch for over a decade. The C-31A Troopship is used to safely transport the Golden Knights to and from more than 300 demonstration sites each year. The C-31A also acts as the platform from which the Golden Knights jump off to perform their precision freefalls from a 2.5-mile ceiling. After the parachutists jump from the aircraft, the C-31A performs a low-altitude, high-speed fly-by to show off the maneuverability of the Troopship platform.|
|C-32||USAF||C-32A||6||Boeing||The military variant of the Boeing 757-200 extended range plane, the Boeing C-32 was procured by the U.S. Air Force to replace its aging fleet of Boeing C-137 Stratoliner transport aircraft. Powered by a duo of wing-mounted Pratt & Whitney 2040 engines providing 41,700 pounds of thrust each, the Boeing C-32 flies at a Mach 0.8 speed of 530 miles an hour for a range of 5,500 nautical miles at a service ceiling of 42,000 feet. The C-32 is deployed with the 1st Airlift Squadron and the 89th Airlift Squadron at Andrews Air Force Base, Maryland. The main air transport platform of the Vice President of the United States is a C-32 dubbed Air Force Two.|
|C-37||USAF||C-37A||9, 2, 2, 1||Gulf-stream||The C-37 is primarily a passenger transport aircraft for high-ranking government and Defense Department officials. The C-37 is similar to the C-20H but with enhanced capabilities – a more advanced avionics suite (the Honeywell SPZ-8500 Flight Management System, a ground proximity warning system (GPWS), TACAN military navigation equipment, and an identification friend or foe (IFF) transponder). The C-37 is also capable of flying distances 50% greater without refueling than the C-20.|
|USA||C-37B||2, 1, 0, 3||Aerospace|
|C-38 Courier||USAF||C-38A||2||Gulf-stream||Powered by two Honeywell TFE 731 engines and holding up to 11 people, the C-38 primarily functions as a distinguished persons transport aircraft but can be modified for medical evacuation or cargo movement. With a range of just under 3,000 miles and a long range cruishing speed of Mach 0.75, the C-38 has immediate coast-to-coast capabilities. Additionally, the military variant is fitted with GPS, secure communications, and an IFF system.|
|C-40 Clipper||USAF||C-40B||4||Boeing||Derived from the Boeing 737-700C, the Clipper is a critical logistical support and medium and heavy cargo transport aircraft. The Navy’s version, C-40A, was developed under the Navy unique fleet essential airlift replacement aircraft (NUFEA-RA) program, replacing the C-9Bs. With three configurations – all-passenger, all-cargo, and combination – the Clipper can hold up to 121 passengers and up to eight pallets of cargo. Equipped with an advanced electronics system including: GATM/FANS operating environment 9RNP-1), RVSM capability, and TACAN/UHF/IFF systems, the C-40A is an advanced logistics aircraft for high-priority passengers and equipment.|
|C-130 Hercules||USAF||C-130E||13||Lockheed Martin||Originally built as a medical evacuation and cargo transport aircraft, the flexible C-130 has developed multiple roles over time including: gunned airborne assault, SAR, weather reconnaissance, aerial refueling, maritime patrol, and other in-theater tactical roles. With STOL (short take-off and landing) abilities, the C-130’s flexibility have made it one of the military’s longest-running tactical operations aircraft.|
|C-130J Super Hercules||USAF||C-130J||10||Lockheed Martin||An upgraded C-130, the Super Hercules was thoroughly updated with new Rolls-Royce AE 2100 D3 turboprops with Dowty R391 composite scimitar propellers, an advanced avionics suite, and other technologies that have given the J-variant 40% greater range, 21% greater speed, and 41% shorter take off.|
|C-145 Skytruck||USAF||M28||10||PZL Mielec||A light cargo transport aircraft, the Skytruck is used to support the U.S. Special Operations Command’s Aviation Foreign Internal Defense (AvFID) theater missions. The aircraft is used to train and advise foreign aviation forces and gun-equipped Skytrucks have been given to them for use against their domestic insurgents.|
|C-146A Wolfhound||USAF||C-146||14||M7 Aerospace||Derived from the Dornier 328, a turboprop commuter airliner, the C-146A is a tactical aircraft designed for US Special Operations Command in the theatre and for non-standard aviation (NSAv) missions assisting in Joint Special Operations Command. Equipped with a Honeywell Primus 2000 avionics system, two Pratt & Whitney turboprop 119C engines, and other electronics, the Wolfhound is a highly flexible aircraft used for quick responsive missions, including casualty evacuation.|
|CT-39 Sabreliner||USN||CT-39G||1||Rockwell Inter-national||Originally a trainer aircraft (T-39) for personnel transport and combat readiness training, the CT-29A is a variant modified for cargo/personnel transport use.|
|HC-130 Combat King/Combat King II||USAF||HC-130N||10||Lockheed Martin||The only dedicated fixed-wing personnel recovery platform in the USAF, the HC-130 is used to deploy troops or recover personnel to contested areas or other hostile territories. The aircraft is also used for humanitarian missions and disaster response. Due to the sensitive nature of the missions that the HC-130 typically undertakes, the HC-130 frequently flies at night in total visual and communicative darkness and is equipped with a night vision goggle (NVG)-compatible interior.|
|KC-10 Extender||USAF||KC-10A||59||Boeing||The militarized version of the DC-10 airliner, the KC-10 functions primarily as a dual-use transport and aerial refueling aircraft. An important element of overseas combat operations, the KC-10 can simultaneously refuel fighters while carrying their support equipment. The KC-10 can hold nearly 170,000 pounds of cargo for nearly 4,400 miles. With a total of six fuel tanks, the KC-10 can carry over 356,000 pounds of fuel.|
|KC-130||USMC||KC-130F||5||Lockheed Martin||The Marine Corps’ primary refueling aircraft, the KC-130 has a 57,500 pound fuel offload capacity using probe and drogue refueling systems.|
|KC-135 Stratotanker||USAF||KC-135R||363||Boeing||The USAF’s primary refueling aircraft, the Stratotanker will eventually be replaced by the developing KC-46 Pegasus due to rising maintenance costs.|
|LC-130 Hercules||USAF||LC-130H||10||Lockheed Martin||A variant of the C-130 Hercules, the LC-130 is mounted with skis for operations into polar regions. During takeoff, the LC-130 is equipped with jet-assisted-takeoff (JATO) rockets to facilitate liftoff from snow surfaces. During landing, the aircraft has retractable skis which can glide onto snow or normal runways. Its primary mission is supporting scientific expeditions into the Arctic and Antarctic.|
|MC-130 Combat Talon II/ Combat Shadow||USAF||MC-130H||20||Lockheed Martin||Used for special operations by the US military, the MC-130 provides infiltration and exfiltration for forces engaged in clandestine missions. Containing an extensive EW suite and terrain-following/terrain-avoidance radars capable of operating in low-altitude, the aircraft is designed for rescue missions into hostile territory as well as psychological operations (i.e. leaflet dropping).|
|VC-25||USAF||VC-25A||2||Boeing||A military version of the Boeing 747, the VC-25 is used to carry the president of the United States. With two main decks and a configuration designed for the executive’s duties, the VC-25 features multiple offices, a conference room, a medical annex, and multiple quarters for journalists and other parties.|
|UC-35||USA||UC-35A||20||Cessna||Based on the Cessna Citation business jet line, the UC-35 is powered by Pratt & Whitney JT15D-5D engines with a Honeywell Primus 1000 EFIS glass cockpit and is used primarily for personnel transport.|
The DoD has allocated $21.1 billion to procure multiple variants of the C-130J aircraft through fiscal year 2014: 129 C-130Js, 63 HC/MC-130Js, and 52 KC-130Js. For future year defense program (FYDP) budgeting (a program projecting costs up to five years), the DoD requests a procurement of an additional 23 C-130Js, 47 HC/MC-130Js, and 6 KC-130Js totaling $12.8 billion.
The C-5 is currently in the second phase of an ongoing Reliability Enhancement and Re-engining Program (RERP). RERP will update the avionics and replace the aging engines of the C-5. After completion of the project, the transport planes will be renamed C-5Ms. $6.8 billion has been appropriated for 2014 with an additional $332 million for 2015. The C-5 RERP will complete in fiscal year 2015.
The Air Force’s KC-46A Tanker Modernization Program is the first of three planned stages to replace the KC-135 tankers. The KC-46A is a modified Boeing 767 that will provide increased aerial refueling capacity along with cargo, aeromedical evacuation, and defense abilities. A total of $49.5 billion has been allocated to the program for 179 aircraft.
The August 2014 humanitarian intervention in Iraq utilized C-130 Hercules aircraft to deliver food, water, and supplies to Yazidi refugees trapped on Mount Sinjar.