KC-135 STRATOTANKER

The Boeing KC-135 Stratotanker is an Aerial Refueling Military Aircraft. It provides the core aerial refueling capability for the United States Air Force and has excelled in this role for more than 50 years. It was the US Air Force's first jet-powered refueling tanker. The primary mission of the KC-135 is the refueling of strategic long-range bombers. It also provides air refueling support to Air Force, Navy and Marine Corps aircraft as well as aircraft of allied nations.

DESIGN AND FEATURES:-

The KC-135 was derived from the Boeing 367-80 jet transport "proof of concept" demonstrator, which was commonly called the "Dash-80”.  The Boeing Company's model 367-80 was the basic design for the commercial 707 passenger plane as well as the KC-135A Stratotanker. The first aircraft flew in August 1956.

 Four turbofans, mounted under 35-degree swept wings, power the KC-135 to takeoffs at gross weights of up to 322,500 pounds. 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 of cargo.

boeing kc-135 stratotanker

One crewmember, known as the boom operator, is stationed in the rear of the plane and controls the boom during in-flight air refueling. A special shuttlecock-shaped drogue attached to and trailing behind the flying boom may be used to refuel aircraft fitted with probes. Some aircraft have been configured with the multipoint refueling system, which consists of special pods mounted on the wingtips.
AIR REFUELING
During air refueling, the large flyable boom attached to the airplane's belly can offload fuel at 6,500 pounds per minute. This is enough fuel in one minute to operate an average family car for one year. Normally during in-flight refueling the boom operator is in radio contact with the receiver aircraft. The hook-up is made by directions given to the receiver aircraft through a system of lights located on the belly of the aircraft just behind the nose gear.

MODIFICATIONS

kc-135's boom operator

Of the original KC-135As, more than 415 have been modified with new CFM-56 engines produced by CFM-International. The re-engined tanker, designated either the KC-135R or KC-135T, can offload 50 percent more fuel, is 25 percent more fuel efficient, costs 25 percent less to operate and is 96 percent quieter than the KC-135A. 


SOME FACTS

During nine years of the Vietnam conflict, KC-135s made 813,000 aerial refuelings of combat aircraft. During the Persian Gulf war, the tankers made 18,700 hookups and transferred 278 million pounds of fuel.

DIFFERENCE BETWEEN 707 AND C135

Structurally, the KC-135 is similar but not identical to the Boeing 707 commercial airliner. It is a swept-wing, long range, high altitude, high speed jet transport. As such the KC-135 is similar in appearance to the 707, but has a narrower fuselage and is shorter than the 707. The KC-135 predates the 707, and is structurally quite different from the civilian airliner.

SPECIFICATIONS:

Primary Function: Aerial refueling and airlift 
Power Plant:  CFM-56 turbofan engines
Thrust: 21,634 pounds each engine
Wingspan: 130 feet, 10 inches (39.88 meters) 
Length: 136 feet, 3 inches (41.53 meters) 
Height: 41 feet, 8 inches (12.7 meters) 
Speed: 530 miles per hour at 30,000 feet (9,144 meters) 
Ceiling: 50,000 feet (15,240 meters) 
Range: 1,500 miles (2,419 kilometers) with 150,000 pounds (68,039 kilograms) of transfer fuel
Maximum Takeoff Weight: 322,500 pounds (146,285 kilograms) 
Maximum Transfer Fuel Load: 200,000 pounds (90,719 kilograms) 
Maximum Cargo Capability: 83,000 pounds (37,648 kilograms), 37 passengers 
Crew: Three: pilot, co-pilot and boom operator. Some KC-135 missions require the addition of a navigator.

Airbus Military’s A330 Multi Role Tanker Transport

Airbus Military’s A330 Multi Role Tanker Transport is the most capable in-flight refuelling platform available today. 

The aircraft has become the market leader in its category, thanks to its flight proven advantages – including superior performance, the latest technology, true multi-role flexibility, a large basic fuel capacity(111 tonnes / 245,000 lb), permanent lower deck freight capacity, and excellent payload/range capability.

As the low-risk solution for air forces worldwide, the A330 MRTT has won the most recent international competitions, being selected by the Royal Australian Air Force, U.K. Royal Air Force, the Royal Saudi Air Force and the United Arab Emirates Air Force & Air Defence AND recently against IL78mki for IAF.

The first airbus Military A330 MRTT was delivered to the RAAF in June 2011, following an extensive development and test programme for what is the world’s only certified and flying new generation tanker/transport aircraft.

It is derived from the best-selling A330 widebody twin-engine commercial airliner, and excels in the full range of operational tanker mission scenarios.  The aircraft also has designed-in flexibility for cargo, passengers and aeromedical evacuation. It combines advanced avionics with Airbus’ proven fly-by-wire control system and the most up-to-date manufacturing techniques, enabling the lowest operating costs. 

The A330 MRTT can directly support a fighter squadron's deployment by carrying its operational personnel and equipment while also performing refuelling escort for the squadron's combat aircraft to an overseas base. This allows the fighter squadron to deploy as a unit, and then quickly ramp up to a combat-level sortie rate after arrival. 

In addition, the A330 MRTT is perfectly suited to undertake additional missions for current and future military forces’ requirements. Its large cabin provides volume for additional mission equipment, and the onboard power system can accommodate add-on loads such as multifunction automated relay terminals (SMART). 

The A330 MRTT’s significant fuel capacity (111 tonnes/245,000 lbs.) – combined with high offload rates – ensures that all receiver aircraft can be refuelled efficiently and quickly. Multi-point refuelling allows the A330 MRTT to top off several receiver aircraft simultaneously. Its state-of-the-art Aerial Refuelling Boom System (ARBS) from Airbus Military, combined with Cobham hose and drogue refuelling systems, provide the unique capability to service probe-equipped and slipway-equipped aircraft during the same mission.

One of the A330 MRTT’s advanced technology features is its all-electric Aerial Refuelling Boom System, which provides highly accurate, reliable in-flight refuelling. Developed  by Airbus Military specifically for the A330 MRTT, the under-fuselage centreline ARBS is the only new-generation boom, and allows the fastest fuel transfer (4,600 litres per minute) – greatly reducing the refuelling operation time. 

Modern fly-by-wire technology incorporated in the centreline ARBS provides enhanced controllability and includes an automatic load alleviation system that greatly aids the boom operator – as well as the receiver aircraft's pilot – during refuelling operations. 

The A330 MRTT also carried two all-digital Cobham 905E hose and drogue pods under the wings, which can simultaneously refuel two probe-equipped receiver aircraft.  In addition, a Cobham 805E hose and drogue under-fuselage refuelling unit can be installed for additional fuel transfer capability.

These air-to-air refuelling (AAR) systems are controlled from a state-of-the-art Fuel Operator Console integrated in the cockpit, and they make the A330 MRTT interoperable with NATO and allied aircraft on the same mission – without downtime needed for reconfiguration. 

The A330 MRTT carries a Universal Air Refuelling Receptacle Slipway Installation (UARRSI) on the forward fuselage above the cockpit, enabling the aircraft to be refuelled by other tankers, increasing its time aloft/range for the most demanding missions. 

Thanks to its true widebody fuselage with the optimised Airbus 222-inch cross-section, the A330 MRTT can also be used as a pure transport aircraft, able to carry up to 380 passengers or a payload of up to 45 tonnes/99,000 lbs. It can also easily be converted to accommodate up to 130 stretchers for medical evacuation. 

As no additional fuel tanks are needed, the A330 MRTT maintains the lower deck forward, aft and bulk cargo hold payload capacity, unaffected by any air-to-air refuelling equipment. 

The versatility of the A330 MRTT enables a wide variety of cargo to be transported – from standard commercial containers, through military, ISO and NATO pallets and containers, to military vehicles.  As an option, the main deck can be configured for cargo transport with the installation of a large forward loading door to allow large items of equipment to be carried, or a total of 34 463-L military pallets.

The A330 MRTT also features a suite of advanced military avionics and mission systems integrated with the civil avionics, and can also be provided with a comprehensive survivability package including defensive aids, along with fuel tank inerting and cockpit armouring.