KC-135 Stratotanker

KC-135 Stratotanker
Description
Role	Mid-air refueling
Crew	4, pilot, copilot, navigator, boom operator
Dimensions
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
Weights
Empty	98,466 lb	44,663 kg
Loaded	297,000 lb	134,700 kg
Maximum take-off	316,000 lb	143,300 kg
Powerplant
Engines	(R/T) - Four CFM International CFM-56 turbofan engines; (E) - Four Pratt & Whitney TF-33-PW-102 turbofan engines
Thrust	(R) - 21,634 lbf (E) - 18,000 lbf	(R) - 96 kN (E) - 80 kN
Performance
Maximum speed	580 mph	933 km/h
Combat range	3,450 mi	5,550 km
Ferry range	9,200 mi	14,800 km
Service ceiling	50,000 ft	15,200 m
Rate of climb	4,900 ft/min	1,490 m/min

The Boeing KC-135 Stratotanker is an aerial refueling tanker aircraft, first manufactured in 1956 and expected to remain in service into the 2040s. 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.

In detail

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.

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 and Air National Guard 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-135T 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.

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 U.S. Strategic Command's 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.

Future development

Over the next few years (as of 2003), the aircraft will undergo upgrades to expand its capabilities and improve its reliability. Among these are improved communications, navigation and surveillance equipment to meet future civil air traffic control needs. The Multi-Point Refueling System Program will add hose and drogue refueling pods near the wingtips, allowing it to service multiple aircraft, and to service probe-carrying aircraft without an adapter.

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.

It seems likely that the KC-135 fleet will be replaced by the Boeing KC-767 Tanker Transport, which was selected in competition with the Airbus A330 MRTT. 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. This is 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.

General characteristics

Primary Function: Aerial refueling and airlift
Prime Contractor: The Boeing Company
Power Plant: KC-135R/T, CFMI CFM56 turbofan engines; KC-135E, Pratt & Whitney TF-33-PW-102 turbofan engines
Thrust: KC-135R, 21,634 lbf (96.233 kN) each engine; KC-135E, 18,000 lbf (80 kN) each engine
Wingspan: 130 ft 10 in (39.88 m)
Length: 136 ft 3 in (41.53 m)
Height: 41 ft 8 in (12.7 m)
Speed: 530 statute miles per hour (850 km/h) at 30,000 ft (9,100 m)
Ceiling: 50,000 ft+ (15,200 m+)
Range: 1,500 statute miles (2,400 km) with 150,000 lb (68,000 kg) of transfer fuel; ferry mission, up to 17,766 km (11,039 statute miles)
Maximum takeoff weight: 322,500 lb (146,300 kg)
Maximum transfer fuel load: 200,000 lb (90,700 kg)
Maximum fuel transfer rate: appr. 6500 lb/min (3000 kg/min) using the boom; appr. 1500 lb/min (700 kg/min) with drogue attached
Maximum cargo capability: 83,000 lb (37,600 kg), 37 passengers
Pallet positions: 6
Crew: four: pilot, co-pilot, navigator, boom operator. Aircraft equipped with PACER CRAG do not have a navigator on most missions. The US Air Force procured a limited number of navigator suites that can be installed for unique missions.
Unit cost: US$39.6 million (FY98 constant dollars)
Date deployed: August 1956
Inventory: active duty, 253; Air National Guard, 222; Air Force Reserve, 70

Operators

Listed alphabetically:

France, Singapore, Turkey, United States.

External links

Modern USAF series	Miscellaneous
Attack--OA/A-10,AC-130H/U	RC-135V/RC-135W Rivet Joint
Bomber--B-52,-2,-1B,F-117A	OC-135B Open Skies
Fighter--F-15/E ,F-16	KC-10 Extender
Electronic--E-3,-4B,-8C EC-130E/J,H	KC-135 Stratotanker
Transport--C-5,-17,-141B, -20,-21	MC-130E/H HC-130P/N
C-22B, -32, -130, -37A, -40B/C	MC-130P Combat Shadow
Trainers--T-1, -37, -38, -43, -6	MH-53J/M Pave Low
Weather--WC-130, -135	HH-60G Pave Hawk
UAV--RQ-1/MQ-1 UAV, Global Hawk	UH-1N Huey
	U-2S/TU-2S
	VC-25 - Air Force One

U.S. military tanker aircraft

Boeing KC-135 | KC-135 | KC-135 Stratotanker | KC-135 Stratotanker