KC-135 Stratotanker
(Redirected from KC-135R)
| KC-135 Stratotanker | |
|---|---|
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| KC-135 refuels a F-22A Raptor | |
| Type | Aerial refuelling and transport |
| Manufacturer | Boeing |
| Maiden flight | August 17, 1956 |
| Introduced | June 1957 |
| Status | Active service |
| Primary user | United States Air Force |
| Produced | 1954-1965 |
| Unit cost | US$39.6 million (FY98 constant dollars) |
| Developed from | Boeing 367-80 |
| Variants | C-135 Stratolifter C-137 Stratoliner |
The Boeing KC-135 Stratotanker is an aerial refueling tanker aircraft, first manufactured in 1956 and expected to remain in service into the 2040s.
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Development
It is derived from the original Boeing jet transport "proof of concept" demonstrator, the Boeing 367-80 (commonly called the "Dash-80"). As such, it has a narrower fuselage and is shorter than the Boeing 707 jetliner.
Developed in the late 1950s this basic airframe is characterized by swept wings and tail, four under wing mounted engine pods, a horizontal stabilizer mounted on the fuselage near the bottom of the vertical stabilizer with positive dihedral on the two horizontal planes and a hi-frequency radio antenna which protrudes forward from the top of the vertical fin or stabilizer. These basic features make it strongly resemble the commercial Boeing 707 and 720 aircraft although, under the skin, it's actually a different aircraft.
The Strategic Air Command had the KC-135 Stratotankers in service from 1957 through 1991 and with the Air National Guard and Air Force Reserve from 1975 through 1991, when they were re-assigned to the Air Mobility Command. Reconnaissance and command post variants, including EC-135 Looking Glass, Post Attack Command & Control Systems were operated by SAC from 1963 through 1991, when they were re-assigned to the Air Combat Command.
Boeing's 367-80 was the basic design for the commercial Boeing 707 passenger aircraft as well as the KC-135A Stratotanker. In 1954 the USAF's Strategic Air Command ordered the first 29 of its future fleet of 732. The first aircraft flew in August 1956 and the initial production Stratotanker was delivered to Castle Air Force Base, California, in June 1957. The last KC-135 was delivered to the Air Force in 1965.
Four turbofans, mounted under 35-degree swept wings, power the KC-135 to takeoffs at gross weights up to 322,500 pounds (146,300 kg). Nearly all internal fuel can be pumped through the tanker's flying boom, the KC-135's primary fuel transfer method. A special shuttlecock-shaped drogue, attached to and trailing behind the flying boom, may be used to refuel aircraft fitted with probes. An operator stationed in the rear of the aircraft controls the boom while lying on their stomach. A cargo deck above the refueling system can hold a mixed load of passengers and cargo. Depending on fuel storage configuration, the KC-135 can carry up to 83,000 pounds (37,600 kg) of cargo.
In Southeast Asia, KC-135 Stratotankers made the air war different from all previous aerial conflicts. Midair refueling brought far-flung bombing targets within reach. Combat aircraft, no longer limited by fuel supplies, were able to spend more time in target areas.
Air Mobility Command (AMC) manages more than 546 total aircraft inventory Stratotankers, of which the Air Force Reserve and Air National Guard fly 292 in support of AMC's mission.
Modifications
Of the original KC-135As, more than 410 have been modified with new CFM56 engines produced by CFM-International. The re-engined tanker, designated either the KC-135R or KC-135T, can offload 50% more fuel, is 25% more fuel efficient, costs 25% less to operate and is 96% quieter than the KC-135A.
Under an earlier modification program, 157 Air Force Reserve (AFRES) and Air National Guard (ANG) tankers were re-engined with the Pratt & Whitney TF-33-PW-102 engines from retired 707 airliners. The re-engined tanker, designated the KC-135E, is 14% more fuel efficient than the KC-135A and can offload 20% more fuel.
The KC-135Q was the variant modified to carry the JP-7 fuel necessary for the SR-71 Blackbird, segregating the JP-7 from the KC-135's own fuel supply. When the KC-135Q model received the CFM-56 engines, it was redesignated the KC-135T model, which was capable of separating the main body tanks from the wing tanks where the KC-135 draws its engine fuel.
The KC-135R/T was a receiver-capable tanker, used for pilot training and operational refueling missions. Currently all KC-135R/T models (Receiver capable) are with the 22nd Air Refueling WIng at McConnell AFB, KS. Most of these are used for force extension and Special Operations missions, and are crewed by highly qualified receiver capable crews. If not used for the receiver mission, these aircraft can be flown just like any other KC-135R.
Through the years, the KC-135 has been altered to do other jobs ranging from flying command post missions to reconnaissance. The EC-135C was a USAF Strategic Air Command flying command post. One EC-135C, codenamed Looking Glass, was continually airborne throughout the Cold War, ready to control bombers and missiles if ground control was lost. RC-135 Rivet Joints are used for special reconnaissance and Air Force Material Command's NKC-135A's are flown in test programs. The Air Combat Command operates the OC-135 Open Skies as an observation platform in compliance with the Open Skies Treaty. In October 2006, WC-135W Constant Phoenix, based at Offutt AFB, was sent to Kadena AFB on Okinawa to detect any radioactive isotopes that would have resulted from nuclear testing by North Korea.[1]
The Multi-Point Refueling System Program added hose and drogue refueling pods near the wingtips, allowing it to service multiple aircraft, and to service probe-carrying aircraft without an adapter.
The EC-135 is slated to be replaced (along with the E-3 Sentry and the E-8 Joint STARS) by the E-10 MC2A, also based upon the 767 airframe.
Recent Developments
In January 2006 Secretary of Defense Donald Rumsfeld announced the cancellation of the KC-767 program which would have replaced some of the KC-135 fleet. This followed public revelations of corruption in how the contract was awarded, as well as controversy regarding the original leasing rather than outright purchase agreement. This is also designed to be a cost-cutting measure and is part of a larger reorganization and redefinition of the Air Force's mission that includes the retirement of the E-4B fleet, the cancellation of the Boeing 767-based E-10 MC2A program, as well as the elimination of all but 58 B-52 Stratofortresses. Secretary of Defense Rumsfeld states that this move will in no way impair the Air Force's ability to deliver the mission of the KC-767 which will be accomplished by continuing upgrades to the KC-135 and KC-10 Extender fleet.
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Operators
Listed alphabetically:
Specifications (KC-135R)
General characteristics<h3>- Crew: 3: pilot, copilot, boom operator (4 for non-PACER CRAG aircraft)
- Length: 136 ft 3 in (41.53 m)
- Wingspan: 130 ft 10 in (39.88 m)
- Height: 41 ft 8 in (12.70 m)
- Wing area: 2,433 ft² (226 m²)
- Empty weight: 98,466 lb (44,663 kg)
- Loaded weight: 297,000 lb (135,000 kg)
- Max takeoff weight: 322,500 lb (146,000 kg)
- Powerplant: 4× (R/T) CFM International CFM-56 turbofan engines, 21,634 lbf (96 kN) each}
- Powerplant: 4× (E) Pratt & Whitney TF-33-PW-102 turbofan engines , 18,000 lbf (80 kN) each
<h3>Performance<h3>- Maximum speed: 580 mph (933 km/h)
- Range: 3,450 mi (5,550 km)
- Service ceiling: 50,000 ft (15,200 m)
- Rate of climb: 4,900 ft/min (1,490 m/min)
References
- ^ Timesonline.co.uk, Cold War aircraft searches the sky for proof of test
- ^ "BAE SYSTEMS delivers final Pacer CRAG KC-135", Aerotech News and Review, 2002-09-20
External links
Related content
Related development<h3>
<h3>Comparable aircraft<h3><h3>Designation sequence<h3><h3>Related lists<h3>Categories
Active United States military aircraft | U.S. military transport aircraft 1950-1959 | U.S. military tanker aircraft