94-580: The Canadair CL-44 was a Canadian turboprop airliner and cargo aircraft based on the Bristol Britannia that was developed and produced by Canadair in the late 1950s and early 1960s. Although innovative, only a small number of the aircraft were produced for the Royal Canadian Air Force (RCAF) (as the CC-106 Yukon ), and for commercial operators worldwide. The aircraft is named after
188-572: A Baku , Azerbaijan -based Soviet Union interceptor deliberately rammed an Argentine Canadair CL-44 from Transporte Aéreo Rioplatense , killing the three Argentines and one Briton on board; the aircraft was delivering arms from Israel to Iran (the Soviet pilot ejected and survived). The CC-106 Yukons retired in March 1971 and were replaced by the CC-137 ( Boeing 707 ). The Yukons might have served longer with
282-616: A different Boeing aircraft ). The KC-135 was the United States Air Force (USAF)'s first jet-powered refueling tanker and replaced the KC-97 Stratofreighter . The KC-135 was initially tasked with refueling strategic bombers, but it was used extensively in the Vietnam War and later conflicts such as Operation Desert Storm to extend the range and endurance of US tactical fighters and bombers. The KC-135 entered service with
376-429: 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 it is a different aircraft. Reconnaissance and command post variants of
470-502: A 100% increase compared to the original J57 engine. The modified tanker, designated KC-135R (modified KC-135A or E) or KC-135T (modified KC-135Q), can offload up to 50% more fuel (on a long-duration sortie), is 25% more fuel-efficient, and costs 25% less to operate than with the previous engines. It is also significantly quieter than the KC-135A, with noise levels at takeoff reduced from 126 to 99 decibels . This 27 dB noise reduction results in
564-467: A Boeing or LTV receiver system and a secure voice SATCOM radio. Three of the aircraft (60-0356, -0357, and -0362) were converted to tankers from RC-135Ds, from which they retained their added equipment. KC-135Q re-engined with CFM56 engines, 54 modified. A new-built variant for France as dual-role tanker/cargo and troop carrier aircraft. 12 were built for the French Air Force with the addition of
658-569: A Quebec-based company receiving a contract so soon after an Ontario-based company had lost a major contract. The USAF also quickly found that buying a foreign aircraft was not easy when American companies wanted the business and they relinquished the contract to Canadair, awarding an order to Boeing for the KC-135 Stratotanker . On the cargo aircraft variant CL-44D4 the entire tail section hinged. It could be opened using hydraulic actuators to load large items quickly. An inflatable seal at
752-536: A Yukon set a new record staying airborne for 23 hours and 51 minutes. These records were unbroken until bettered by the Boeing 747SP in 1975. By the time of their retirement, Yukons had flown 65 million miles, 1.5 billion passenger miles and 360 million ton-miles. The CL-44D4 was briefly considered for purchase by the United States Air Force in the 1960s but the project was never culminated due to political backlash in Canada and
846-406: A constant-speed propeller increase their pitch as aircraft speed increases. Another benefit of this type of propeller is that it can also be used to generate reverse thrust to reduce stopping distance on the runway. Additionally, in the event of an engine failure, the propeller can be feathered , thus minimizing the drag of the non-functioning propeller. While the power turbine may be integral with
940-719: A drogue adapter on the refueling boom. Given Boeing model numbers 717-164 and 717-165. 11 surviving C-135Fs upgraded with CFM International F108 turbofans between 1985 and 1988. Later modified with MPRS wing pods. An airborne command post modified in 1984 to support CINCCENT . Aircraft 55-3125 was the only EC-135Y. Unlike its sister EC-135N, it was a true tanker that could also receive in-flight refueling. Pratt & Whitney TF33-PW-102. Retired to 309th AMARG at Davis-Monthan AFB, AZ. Note Italy has been reported in some sources as operating several KC-135s, however these are Boeing 707-300s converted to tanker configuration. As of 2020, 52 Stratotankers have been lost to accidents during
1034-416: A large amount of air by a small degree than a small amount of air by a large degree, a low disc loading (thrust per unit disc area) increases the aircraft's energy efficiency , and this reduces the fuel use. Propellers work well until the flight speed of the aircraft is high enough that the airflow past the blade tips reaches the speed of sound. Beyond that speed, the proportion of the power that drives
SECTION 10
#17328593338181128-548: A replacement for its C-54GM North Star , itself an extensive redesign of the Douglas C-54 Skymaster . Among many changes, the proposed new aircraft was powered by Merlin engines. Canadair began work on a long range transport primarily intended to provide personnel and logistics support for Canadian Forces in Europe. In January 1957 Canadair received a contract for eight aircraft, later increased to 12. The RCAF designation for
1222-498: A sound pressure level of about 5% of the original level. The KC-135R's operational range is 60% greater than the KC-135E for comparable fuel offloads, providing a wider range of basing options. Upgrading the remaining KC-135Es into KC-135Rs is no longer in consideration; this would have cost approximately US$ 3 billion, $ 24 million per aircraft. According to USAF data, the KC-135 fleet had
1316-575: A test-bed not intended for production. It first flew on 20 September 1945. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Clyde , the first turboprop engine to receive a type certificate for military and civil use, and the Dart , which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years. The Dart-powered Vickers Viscount
1410-427: A total operation and support cost in fiscal year 2001 of about $ 2.2 billion (~$ 3.62 billion in 2023). The older E model aircraft averaged total costs of about $ 4.6 million per aircraft, while the R models averaged about $ 3.7 million per aircraft. Those costs include personnel, fuel, maintenance, modifications, and spare parts. In order to expand the KC-135's capabilities and improve its reliability,
1504-429: Is a turbine engine that drives an aircraft propeller . A turboprop consists of an intake , reduction gearbox , compressor , combustor , turbine , and a propelling nozzle . Air enters the intake and is compressed by the compressor. Fuel is then added to the compressed air in the combustor, where the fuel-air mixture then combusts . The hot combustion gases expand through the turbine stages, generating power at
1598-407: Is achieved through the use of water injection on takeoff, as opposed to "wet thrust" when used to describe an afterburning engine . 670 US gallons (2,500 L) of water are injected into the engines over the course of three minutes. The water is injected into the inlet and the diffuser case in front of the combustion case. The water cools the air in the engine to increase its density; it also reduces
1692-492: Is currently flying double its planned yearly flying hour program to meet airborne refueling requirements, and has resulted in higher than forecast usage and sustainment costs. In March 2009, the Air Force indicated that KC-135s would require additional skin replacement to allow their continued use beyond 2018. The USAF decided to replace the KC-135 fleet. However, the fleet is large and will need to be replaced gradually. Initially
1786-482: Is normally a constant-speed (variable pitch) propeller type similar to that used with larger aircraft reciprocating engines , except that the propeller-control requirements are very different. Due to the turbine engine's slow response to power inputs, particularly at low speeds, the propeller has a greater range of selected travel in order to make rapid thrust changes, notably for taxi, reverse, and other ground operations. The propeller has 2 modes, Alpha and Beta. Alpha
1880-494: Is sacrificed in favor of shaft power, which is obtained by extracting additional power (beyond that necessary to drive the compressor) from turbine expansion. Owing to the additional expansion in the turbine system, the residual energy in the exhaust jet is low. Consequently, the exhaust jet produces about 10% of the total thrust. A higher proportion of the thrust comes from the propeller at low speeds and less at higher speeds. Turboprops have bypass ratios of 50–100, although
1974-448: Is significantly more unforgiving of pilot error in the receiving aircraft than conventional trailing hose arrangements; an aircraft so fitted is also incapable of refueling by the normal flying boom method until the attachment is removed. 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 (38,000 kg) of cargo. The KC-135
SECTION 20
#17328593338182068-404: Is the mode for all flight operations including takeoff. Beta, a mode typically consisting of zero to negative thrust, is used for all ground operations aside from takeoff. The Beta mode is further broken down into 2 additional modes, Beta for taxi and Beta plus power. Beta for taxi as the name implies is used for taxi operations and consists of all pitch ranges from the lowest alpha range pitch, all
2162-657: The Air Education and Training Command (AETC). All AFRC KC-135s and most of the ANG KC-135 fleet became operationally-gained by AMC, while Alaska Air National Guard and Hawaii Air National Guard KC-135s became operationally-gained by PACAF. AMC managed 396 Stratotankers, of which the AFRC and ANG flew 243 in support of AMC's mission as of May 2018. The KC-135 is one of a few military aircraft types with over 50 years of continuous service with its original operator as of 2009. Israel
2256-707: The KC-X program with a request for proposal (RFP). KC-X was the first phase of three acquisition programs meant to replace the KC-135 fleet. On 29 February 2008, the US Defense Department announced that it had selected the EADS / Northrop Grumman "KC-30" (to be designated the KC-45A ) over the Boeing KC-767. Boeing protested the award on 11 March 2008, citing irregularities in the competition and bid evaluation. On 18 June 2008,
2350-587: The Langley Research Center , were tested at Armstrong, using an NKC-135A tanker loaned to NASA by the Air Force. Winglets are small, nearly vertical fins installed on an aircraft's wing tips. The results of the research showed that drag was reduced and range could be increased by as much as 7 percent at cruise speeds. Winglets are now being incorporated into most new commercial and military transport/passenger jets, as well as business aviation jets. NASA also has operated several KC-135 aircraft (without
2444-673: The Mojave Airport in California. Block 40.6 allows the KC-135 to comply with global air-traffic management . The latest block upgrade to the KC-135, the Block 45 program, is online with the first 45 upgraded aircraft delivered by January 2017. Block 45 adds a new glass cockpit digital display, radio altimeter, digital autopilot, digital flight director and computer updates. The original, no longer procurable, analog instruments, including all engine gauges, were replaced. Rockwell Collins again supplied
2538-616: The P-3 Orion , and the C-130 Hercules military transport aircraft. The first turbine-powered, shaft-driven helicopter was the Kaman K-225 , a development of Charles Kaman 's K-125 synchropter , which used a Boeing T50 turboshaft engine to power it on 11 December 1951. December 1963 saw the first delivery of Pratt & Whitney Canada's PT6 turboprop engine for the then Beechcraft 87, soon to become Beechcraft King Air . 1964 saw
2632-830: The Piper Meridian , Socata TBM , Pilatus PC-12 , Piaggio P.180 Avanti , Beechcraft King Air and Super King Air . In April 2017, there were 14,311 business turboprops in the worldwide fleet. Between 2012 and 2016, the ATSB observed 417 events with turboprop aircraft, 83 per year, over 1.4 million flight hours: 2.2 per 10,000 hours. Three were "high risk" involving engine malfunction and unplanned landing in single‑engine Cessna 208 Caravans , four "medium risk" and 96% "low risk". Two occurrences resulted in minor injuries due to engine malfunction and terrain collision in agricultural aircraft and five accidents involved aerial work: four in agriculture and one in an air ambulance . Jane's All
2726-590: The Tupolev Tu-114 can reach 470 kn (870 km/h; 540 mph). Large military aircraft , like the Tupolev Tu-95 , and civil aircraft , such as the Lockheed L-188 Electra , were also turboprop powered. The Airbus A400M is powered by four Europrop TP400 engines, which are the second most powerful turboprop engines ever produced, after the 11 MW (15,000 hp) Kuznetsov NK-12 . In 2017,
2820-651: The United States . The USAF purchase of the CL-44 was complicated by two factors. It came in the aftermath of the cancellation of the Avro Canada CF-105 Arrow and involved a "swap deal" wherein 100 McDonnell F-101 Voodoo fighters were obtained in return for a contract for 232 CL-44-D4 transports for the Military Air Transport Service (MATS). The political controversy that resulted led to problems for
2914-985: The 309th AMARG at Davis-Monthan AFB by September 2009 and replaced with R models. Test-configured KC-135E. 55-3132 NKC-135E "Big Crow I" & 63-8050 NKC-135B "Big Crow II" used as airborne targets for the Boeing YAL-1 Airborne Laser carrier. KC-135As modified to carry JP-7 fuel necessary for the SR-71 Blackbird, 56 modified, survivors to KC-135T. 4 JC/KC-135As converted to Rivet Stand (Later Rivet Quick ) configuration for reconnaissance and evaluation of above ground nuclear test (55-3121, 59–1465, 59–1514, 58–0126; 58-0126 replaced 59-1465 after it crashed in 1967). These aircraft were powered by Pratt & Whitney J57 engines and were based at Offutt AFB , Nebraska . KC-135As and some KC-135Es re-engined with CFM56 engines, more than 417 converted Receiver-capable KC-135R Stratotanker; eight modified with either
Canadair CL-44 - Misplaced Pages Continue
3008-430: The 707, and is structurally quite different from the civilian airliner. Boeing gave the future KC-135 tanker the initial designation Model 717. In 1954 USAF's Strategic Air Command (SAC) held a competition for a jet-powered aerial refueling tanker. Lockheed Corporation 's tanker version of the proposed Lockheed L-193 airliner with rear fuselage-mounted engines was declared the winner in 1955. Since Boeing's proposal
3102-631: The 707. In 1954, the USAF placed an initial order for 29 KC-135As, the first of an eventual 820 of all variants of the basic C-135 family. 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 USAF in 1965. Developed in the early 1950s, the basic airframe is characterized by 35-degree aft swept wings and tail , four underwing-mounted engine pods,
3196-458: The Air Force, only a few KC-135s would reach these limits by 2040, when some aircraft would be about 80 years old. A later 2005 Air Force study estimated that KC-135Es upgraded to the R standard could remain in use until 2030. In 2006, the KC-135E fleet was flying an annual average of 350 hours per aircraft and the KC-135R fleet was flying an annual average of 710 hours per aircraft. The KC-135 fleet
3290-451: The Britannia 300 with two large cargo doors added on the port side on some aircraft, while the cabin was pressurised to maintain a cabin altitude of 2,400 m at 9,000 m (30,000 ft). The design used modified CL-28 wings and controls. The Yukon could accommodate 134 passengers and a crew of nine. In the casualty evacuation role, it could take 80 patients and a crew of 11. The rollout of
3384-689: The CL-44D4. Loftleiðir was the only passenger operator of the CL-44J, variant of CL-44D4 stretched on request by Canadair. It was the largest passenger aircraft flying over the Atlantic Ocean at that time. Loftleiðir marketed the CL-44J under the name "Rolls-Royce 400 PropJet". This led to the confusion that the CL-44J is sometimes referred to as the Canadair-400. Loftleiðir Icelandic Airlines merged with Air Iceland in 1973 and became today's Icelandair . In 1981
3478-537: The Canadian Forces Air Transport Command but for two factors: the need for an aircraft which could operate as an in-flight refueling tanker, and the chronic shortage and high cost of spares, the latter resulting because the CL-44 had never gone into large-scale production. All Yukons were sold to South American and African operators as they could not be registered in North America or Europe since
3572-524: The Canadian territory of Yukon . In the 1950s, Canadair acquired a licence to build the Bristol Britannia airliner. Their first use of it was to build the heavily modified Canadair CL-28 Argus patrol aircraft (RCAF designation CP-107 ) that combined the Britannia's wings and tail sections with a new fuselage and engines. The resulting aircraft had lower speed and service ceiling, but it had two bomb bays and greatly extended loiter times. The RCAF required
3666-518: The FAA refused to certify the original windshields which came from the Bristol Britannia because they did not meet flight crew vision standards. The General Dynamics CV880/990 windshields were compatible enough to be adopted into the flight deck structure, but the cost was prohibitive. The CC-106 had the original Bristol Britannia windshield and, on its retirement from RCAF operations, the cost of conversion
3760-565: The KC-135 Stratotanker in service with Regular Air Force SAC units from 1957 through 1992 and with SAC-gained ANG and AFRES units from 1975 through 1992. Following a major USAF reorganization that resulted in the inactivation of SAC in 1992, most KC-135s were reassigned to the newly created AMC. While AMC gained the preponderance of the aerial refueling mission, a small number of KC-135s were also assigned directly to United States Air Forces in Europe (USAFE), Pacific Air Forces (PACAF) and
3854-412: The KC-135's wings. The pods allow refueling of U.S. Navy, U.S. Marine Corps and most NATO tactical jet aircraft while keeping the tail-mounted refueling boom. The pods themselves are Flight Refueling Limited MK.32B model pods, and refuel via the probe and drogue method common to Navy/Marine Corps tactical jets, rather than the primary " flying boom " method used by Air Force fixed-wing aircraft. This allows
Canadair CL-44 - Misplaced Pages Continue
3948-641: The KC-135Q model received the CFM56 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 only external difference between a KC-135R and a KC-135T is the presence of a clear window on the underside of the empennage of the KC-135T where a remote controlled searchlight is mounted. It also has two ground refueling ports, located in each rear wheel well so ground crews can fuel both
4042-448: The KC-97, the mixed gasoline/kerosene fuel system was clearly not desirable and it was obvious that a jet-powered tanker aircraft would be the next development, having a single type of fuel for both its own engines and for passing to receiver aircraft. The 230 mph (370 km/h) cruise speed of the slower, piston-engined KC-97 was also a serious issue, as using it as an aerial tanker forced
4136-464: The RC-135As on-board photo-mapping systems. Later re-engined with Pratt & Whitney TF33 engines and a cockpit update to KC-135E standards in 1990 and were retired to the 309th AMARG at Davis-Monthan AFB , AZ in 2007. Air National Guard and Air Force Reserve KC-135As re-engined with Pratt & Whitney TF33-PW-102 engines from retired 707 airliners (161 modified). All E model aircraft were retired to
4230-519: The Soviet Union had the technology to create the airframe for a jet-powered strategic bomber comparable to Boeing's B-52 Stratofortress , they instead produced the Tupolev Tu-95 Bear, powered with four Kuznetsov NK-12 turboprops, mated to eight contra-rotating propellers (two per nacelle) with supersonic tip speeds to achieve maximum cruise speeds in excess of 575 mph, faster than many of
4324-721: The US Government Accountability Office sustained Boeing's protest of the selection of the Northrop Grumman/EADS's tanker. In February 2010, the US Air Force restarted the KC-X competition with the release of a revised request for proposal (RFP). After evaluating bids, the USAF selected Boeing's 767-based tanker design, with the military designation KC-46 , as a replacement in February 2011. The first KC-46A Pegasus
4418-588: The USAF from formally retiring them. The final KC-135E, tail number 56-3630 , was delivered by the 101st Air Refueling Wing to the 309th Aerospace Maintenance and Regeneration Group (AMARG) at Davis–Monthan Air Force Base in September 2009. The second modification program retrofitted 500 aircraft with new CFM International CFM56 (military designation: F108) high-bypass turbofan engines produced by General Electric and Safran . The CFM56 engine produces approximately 22,500 lbf (100 kN) of thrust, nearly
4512-490: The USAF in 1957; it is one of nine military fixed-wing aircraft with over 60 years of continuous service with its original operator. The KC-135 was supplemented by the larger McDonnell Douglas KC-10 Extender . Studies have concluded that many of the aircraft could be flown until 2030, although maintenance costs have greatly increased. The KC-135 is to be partially replaced by the Boeing KC-46 Pegasus . Starting in 1950
4606-540: The USAF operated the world's first production aerial tanker, the Boeing KC-97 Stratofreighter , a gasoline fueled piston-engined Boeing Stratocruiser (USAF designation C-97 Stratofreighter ) with a Boeing-developed flying boom and extra kerosene (jet fuel) tanks feeding the boom. The Stratocruiser airliner itself was developed from the Boeing B-29 Superfortress bomber after World War II . In
4700-499: The World's Aircraft . 2005–2006. Boeing KC-135 Stratotanker The Boeing KC-135 Stratotanker is an American military aerial refueling tanker aircraft that was developed from the Boeing 367-80 prototype, alongside the Boeing 707 airliner. It has a narrower fuselage and is shorter than the 707. Boeing gave the aircraft the internal designation of Model 717 (number later assigned to
4794-458: The Yukon was a near-disaster because the prototype could not be pushed out of the hangar since the vertical fin could not clear the hangar doors. The first flight took place 15 November 1959 at Cartierville Airport . During test flights many problems were encountered, from complete electrical failure to engines shaking loose and almost falling off. Rolls-Royce had problems delivering engines, resulting in
SECTION 50
#17328593338184888-568: The aircraft has undergone a number of avionics upgrades. Among these was the Pacer-CRAG program (compass, radar and GPS) which ran from 1999 to 2002 and modified all the aircraft in the inventory to eliminate the Navigator position from the flight crew. The fuel management system was also replaced. The program development was done by Rockwell Collins in Iowa and installation was performed by BAE Systems at
4982-706: The aircraft, including the RC-135 Rivet Joint and EC-135 Looking Glass aircraft were operated by SAC from 1963 through 1992, when they were reassigned to the Air Combat Command (ACC). The USAF EC-135 Looking Glass was subsequently replaced in its role by the U.S. Navy E-6 Mercury aircraft, a new build airframe based on the Boeing 707-320B. All KC-135s were originally equipped with Pratt & Whitney J57-P-59W turbojet engines, which produced 10,000 lbf (44 kN) of thrust dry, and approximately 13,000 lbf (58 kN) of thrust wet . Wet thrust
5076-543: The body tanks and wing tanks separately. Eight KC-135R aircraft are receiver-capable tankers, commonly referred to as KC-135R(RT). All eight aircraft were with the 22d Air Refueling Wing at McConnell AFB , Kansas, in 1994. They are primarily 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. The Multi-point Refueling Systems (MPRS) modification adds refueling pods to
5170-417: The compressor intake is at the aft of the engine, and the exhaust is situated forward, reducing the distance between the turbine and the propeller. Unlike the small-diameter fans used in turbofan engines, the propeller has a large diameter that lets it accelerate a large volume of air. This permits a lower airstream velocity for a given amount of thrust. Since it is more efficient at low speeds to accelerate
5264-459: The control system. The turboprop system consists of 3 propeller governors , a governor, and overspeed governor, and a fuel-topping governor. The governor works in much the same way a reciprocating engine propeller governor works, though a turboprop governor may incorporate beta control valve or beta lift rod for beta operation and is typically located in the 12 o'clock position. There are also other governors that are included in addition depending on
5358-493: The first jet aircraft and comparable to jet cruising speeds for most missions. The Bear would serve as their most successful long-range combat and surveillance aircraft and symbol of Soviet power projection through to the end of the 20th century. The USA used turboprop engines with contra-rotating propellers, such as the Allison T40 , on some experimental aircraft during the 1950s. The T40-powered Convair R3Y Tradewind flying-boat
5452-552: The first batch of replacement planes was to be an air tanker version of the Boeing 767 , leased from Boeing . In 2003, this was changed to contract where the Air Force would purchase 80 KC-767 aircraft and lease 20 more. In December 2003, the Pentagon froze the contract and in January 2006, the KC-767 contract was canceled. This move followed public revelations of corruption in how the contract
5546-546: The first deliveries of the Garrett AiResearch TPE331 , (now owned by Honeywell Aerospace ) on the Mitsubishi MU-2 , making it the fastest turboprop aircraft for that year. In contrast to turbofans , turboprops are most efficient at flight speeds below 725 km/h (450 mph; 390 knots) because the jet velocity of the propeller (and exhaust) is relatively low. Modern turboprop airliners operate at nearly
5640-615: The following: One CC-106 is known to have been preserved. The fuselage of construction number 13, last registered as HC-AZH, has been converted into a nightclub in Cuenca, Ecuador . Additionally, the single CL-44-O Skymonster remains extant at Bournemouth Airport in the United Kingdom. Data from http://en.avia.pro/blog/canadair-cl-44-tehnicheskie-harakteristiki-foto General characteristics Performance Related development Related lists Turboprop A turboprop
5734-558: The gas generator section, many turboprops today feature a free power turbine on a separate coaxial shaft. This enables the propeller to rotate freely, independent of compressor speed. Alan Arnold Griffith had published a paper on compressor design in 1926. Subsequent work at the Royal Aircraft Establishment investigated axial compressor-based designs that would drive a propeller. From 1929, Frank Whittle began work on centrifugal compressor-based designs that would use all
SECTION 60
#17328593338185828-455: The gas power produced by the engine for jet thrust. The world's first turboprop was designed by the Hungarian mechanical engineer György Jendrassik . Jendrassik published a turboprop idea in 1928, and on 12 March 1929 he patented his invention. In 1938, he built a small-scale (100 Hp; 74.6 kW) experimental gas turbine. The larger Jendrassik Cs-1 , with a predicted output of 1,000 bhp,
5922-524: The hinge-break enabled cabin pressure to be maintained, and eight hydraulic-operated locks assured structural integrity. The tail could be opened from controls within the tail in 90 seconds. The flight controls at the joint were maintained by a system of push pads. The CL-44D4 was the first large aircraft to be able to "swing" its tail, although some small naval aircraft had this feature to ease storage. These, however, required rigging before flight. There were only four original customers who bought and operated
6016-493: The late 1970s and early 1980s. The modified tanker, designated the KC-135E, was 14% more fuel-efficient than the KC-135A and could offload 20% more fuel on long-duration flights. Only the KC-135E aircraft were equipped with thrust reversers for aborted takeoffs and shorter landing roll-outs. The KC-135E fleet has since either been retrofitted as the R-model configuration or placed into long-term storage ("XJ"), as Congress has prevented
6110-520: The major avionic modules, with modification done at Tinker AFB . The KC-135Q variant was modified to carry JP-7 fuel necessary for the Lockheed SR-71 Blackbird by separating the JP-7 from the KC-135's own fuel supply (the body tanks carrying JP-7, and the wing tanks carrying JP-4 or JP-8 ). The tanker also had special fuel systems for moving the different fuels between different tanks. When
6204-503: The mission, the Navy and Marine Corps not having fitted their aircraft with flying boom receptacles since the USAF boom system was impractical for aircraft carrier operations. Crews also helped to bring in damaged aircraft which could sometimes fly while being fed by fuel to a landing site or to ditch over the water (specifically those with punctured fuel tanks). KC-135s continued their tactical support role in later conflicts such as Operation Desert Storm and current aerial strategy. SAC had
6298-598: The model number 717-166. All four RC-135As ( Pacer Swan ) were modified to partial KC-135A configuration in 1979. The four aircraft (serial numbers 63-8058, 63-8059, 63-8060 and 63-8061 ) were given a unique designation KC-135D as they differed from the KC-135A in that they were built with a flight engineer's position on the flight deck. The flight engineer's position was removed when the aircraft were modified to KC-135 standards but they retained their electrically powered wing flap secondary (emergency) drive mechanism and second air conditioning pack which had been used to cool
6392-406: The model, such as an overspeed and fuel topping governor on a Pratt & Whitney Canada PT6 , and an under-speed governor on a Honeywell TPE331 . The turboprop is also distinguished from other kinds of turbine engine in that the fuel control unit is connected to the governor to help dictate power. To make the engine more compact, reverse airflow can be used. On a reverse-flow turboprop engine,
6486-509: The most widespread turboprop airliners in service were the ATR 42 / 72 (950 aircraft), Bombardier Q400 (506), De Havilland Canada Dash 8 -100/200/300 (374), Beechcraft 1900 (328), de Havilland Canada DHC-6 Twin Otter (270), Saab 340 (225). Less widespread and older airliners include the BAe Jetstream 31 , Embraer EMB 120 Brasilia , Fairchild Swearingen Metroliner , Dornier 328 , Saab 2000 , Xian MA60 , MA600 and MA700 , Fokker 27 and 50 . Turboprop business aircraft include
6580-459: The new design was CC-106 Yukon , while the company's civilian variant was known as the CL-44-6 . In company parlance the CL-44 was simply "the Forty-Four." The RCAF specified the CL-44 to be equipped with Bristol Orion engines. When the British Ministry of Supply canceled the Orion program, the RCAF revised the specifications to substitute the Rolls-Royce Tyne 11 . The CL-44 fuselage was lengthened, making it 12 ft 4 in (3.75 m) longer than
6674-411: The newer jet-powered military aircraft to slow down to mate with the tanker's boom. Like its sibling, the commercial Boeing 707 jet airliner , the KC-135 was derived from the Boeing 367-80 jet transport "proof of concept" demonstrator, which was commonly called the "Dash-80". 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
6768-416: The pilot not being able to see out of the rear of the aircraft for backing and the amount of debris reverse stirs up, manufacturers will often limit the speeds beta plus power may be used and restrict its use on unimproved runways. Feathering of these propellers is performed by the propeller control lever. The constant-speed propeller is distinguished from the reciprocating engine constant-speed propeller by
6862-403: The point of exhaust. Some of the power generated by the turbine is used to drive the compressor and electric generator . The gases are then exhausted from the turbine. In contrast to a turbojet or turbofan , the engine's exhaust gases do not provide enough power to create significant thrust, since almost all of the engine's power is used to drive the propeller. Exhaust thrust in a turboprop
6956-494: The propeller that is converted to propeller thrust falls dramatically. For this reason turboprop engines are not commonly used on aircraft that fly faster than 0.6–0.7 Mach , with some exceptions such as the Tupolev Tu-95 . However, propfan engines, which are very similar to turboprop engines, can cruise at flight speeds approaching 0.75 Mach. To maintain propeller efficiency across a wide range of airspeeds, turboprops use constant-speed (variable-pitch) propellers. The blades of
7050-477: The propeller. This allows for propeller strike or similar damage to occur without damaging the gas generator and allowing for only the power section (turbine and gearbox) to be removed and replaced in such an event, and also allows for less stress on the start during engine ground starts. Whereas a fixed shaft has the gearbox and gas generator connected, such as on the Honeywell TPE331 . The propeller itself
7144-446: The propulsion airflow is less clearly defined for propellers than for fans. The propeller is coupled to the turbine through a reduction gear that converts the high RPM /low torque output to low RPM/high torque. This can be of two primary designs, free-turbine and fixed. A free-turbine turboshaft found on the Pratt & Whitney Canada PT6 , where the gas generator is not connected to
7238-585: The same speed as small regional jet airliners but burn two-thirds of the fuel per passenger. Compared to piston engines, their greater power-to-weight ratio (which allows for shorter takeoffs) and reliability can offset their higher initial cost, maintenance and fuel consumption. As jet fuel can be easier to obtain than avgas in remote areas, turboprop-powered aircraft like the Cessna Caravan and Quest Kodiak are used as bush airplanes . Turboprop engines are generally used on small subsonic aircraft, but
7332-625: The sarcastically-named "Yukon gliders" being parked outside Canadair as late as 1961. Initially, the CL-44-6 was produced for the RCAF as the CC-106 Yukon . Once initial problems were resolved, in RCAF service the Yukon performed well and in December 1961, a Yukon set a world record for its class when it flew 6,750 mi (10,860 km) from Tokyo to RCAF Station Trenton, Ontario, in 17 hours, three minutes at an average speed of 400 mph (640 km/h). Later,
7426-959: The tanker equipment installed) as their famed Vomit Comet zero-gravity simulator aircraft. The longest-serving (1973 to 1995) version was KC-135A, AF Ser. No. 59-1481 , named Weightless Wonder IV and registered as N930NA. Between 1993 and 2003, the amount of KC-135 depot maintenance work doubled, and the overhaul cost per aircraft tripled. In 1996, it cost $ 8,400 per flight hour for the KC-135, and in 2002 this had grown to $ 11,000. The Air Force's 15-year estimates project further significant cost growth through fiscal year 2017. KC-135 fleet operations and support costs were estimated to grow from about $ 2.2 billion in fiscal year 2003 to $ 5.1 billion (2003 dollars) in fiscal year 2017, an increase of over 130 percent, which represented an annual operating cost growth rate of about 6.2 percent. The USAF projected that E and R models have lifetime flying hour limits of 36,000 and 39,000 hours, respectively. According to
7520-617: The tanker to refuel two receivers at the same time, which increases throughput compared to the boom drogue adapter. A number of KC-135A and KC-135B aircraft have been modified to EC-135, RC-135 and OC-135 configurations for use in several different roles (although these could also be considered variants of the C-135 Stratolifter family). The KC-135R has four turbofan engines, mounted under 35-degree swept wings, which power it to takeoffs at gross weights up to 322,500 pounds (146,300 kg). Nearly all internal fuel can be pumped through
7614-455: The tanker's flying boom , the KC-135's primary fuel transfer method. A boom operator stationed in the rear of the aircraft controls the boom while lying prone, viewing through a window at the bottom of the tail. Both the flying boom and operator's station are similar to those of the previous KC-97. A special shuttlecock-shaped drogue, attached to and trailing behind the flying boom, may be used to refuel aircraft fitted with probes. This apparatus
7708-533: The turbine gas temperature, which is a primary limitation on many jet engines. This allows the use of more fuel for proper combustion and creates more thrust for short periods of time, similar in concept to " War Emergency Power " in a piston-engined aircraft. In the 1980s, the first modification program retrofitted 157 Air Force Reserve (AFRES) and Air National Guard (ANG) tankers with the Pratt & Whitney TF33-PW-102 turbofan engines from 707 airliners retired in
7802-410: The way down to zero pitch, producing very little to zero-thrust and is typically accessed by moving the power lever to a beta for taxi range. Beta plus power is a reverse range and produces negative thrust, often used for landing on short runways where the aircraft would need to rapidly slow down, as well as backing operations and is accessed by moving the power lever below the beta for taxi range. Due to
7896-465: Was already flying, the KC-135 could be delivered two years earlier and Air Force Secretary Harold E. Talbott ordered 250 KC-135 tankers until Lockheed's design could be manufactured. In the end, orders for the Lockheed tanker were dropped rather than supporting two tanker designs. Lockheed never produced its jet airliner, while Boeing would eventually dominate the market with a family of airliners based on
7990-455: Was awarded, as well as controversy regarding the original leasing rather than outright purchase agreement. The then Secretary of Defense Rumsfeld stated that that move would in no way impair the Air Force's ability to deliver the mission of the KC-767, which would be accomplished by implementing continuing upgrades to the KC-135 and KC-10 Extender fleet. In January 2007, the U.S. Air Force launched
8084-675: Was delivered to the U.S. Air Force on 10 January 2019. Two export users of the KC-135, the French Air and Space Force and the Republic of Singapore Air Force took deliveries of Airbus A330 MRTTs as replacements for their Stratotankers. Original production version powered by four Pratt & Whitney J57s , 732 built. Given the Boeing model numbers 717-100A, 717-146 and 717-148. Test-configured KC-135A. Airborne command post version equipped with turbofan engines, 17 built. Provided with in-flight refueling capability and redesignated EC-135C. Given
8178-453: Was destroyed in a bombing raid. In 1941, the engine was abandoned due to war, and the factory converted to conventional engine production. The first mention of turboprop engines in the general public press was in the February 1944 issue of the British aviation publication Flight , which included a detailed cutaway drawing of what a possible future turboprop engine could look like. The drawing
8272-651: Was estimated at $ 250,000.00 per unit, cost alone precluding its use in North America and Europe. In 1974, a special exclusion was granted for the CC-106 (Cargo) for civil operations in Canada. Four original customers who bought and operated the CL-44D4 were: Seaboard World Airlines, The Flying Tiger Line, Slick Airways and the Icelandic Airlines Loftleiðir. All other operators operated second-hand aircraft. ♠ original operators The Canadair CL-44 suffered 21 hull loss incidents during its operational history including
8366-668: Was initially purchased to support SAC bombers, but by the late 1960s, in the Southeast Asia theater, the KC-135 Stratotanker's ability as a force multiplier came to the fore. Midair refueling of F-105 and F-4 fighter-bombers as well as B-52 bombers brought far-flung bombing targets within reach, and allowed fighter missions to spend hours at the front, rather than a few minutes, which was usual due to their limited fuel reserves and high fuel consumption. KC-135 crews refueled both USAF and Navy/ Marine Corps aircraft; though they would have to change to probe and drogue adapters depending upon
8460-656: Was offered KC-135s again in 2013, after turning down the aging aircraft twice due to expense of keeping them flying. The IAF again rejected the offered KC-135Es, but said that it would consider up to a dozen of the newer KC-135Rs. Besides its primary role as an inflight aircraft refueler, the KC-135, designated NKC-135, has assisted in several research projects at the NASA Armstrong Flight Research Center at Edwards Air Force Base , California. One such project occurred between 1979 and 1980 when special wingtip " winglets ", developed by Richard Whitcomb of
8554-635: Was operated by the U.S. Navy for a short time. The first American turboprop engine was the General Electric XT31 , first used in the experimental Consolidated Vultee XP-81 . The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power. The technology of Allison's earlier T38 design evolved into the Allison T56 , used to power the Lockheed Electra airliner, its military maritime patrol derivative
8648-629: Was produced and tested at the Ganz Works in Budapest between 1937 and 1941. It was of axial-flow design with 15 compressor and 7 turbine stages, annular combustion chamber. First run in 1940, combustion problems limited its output to 400 bhp. Two Jendrassik Cs-1s were the engines for the world's first turboprop aircraft – the Varga RMI-1 X/H . This was a Hungarian fighter-bomber of WWII which had one model completed, but before its first flight it
8742-593: Was the first turboprop aircraft of any kind to go into production and sold in large numbers. It was also the first four-engined turboprop. Its first flight was on 16 July 1948. The world's first single engined turboprop aircraft was the Armstrong Siddeley Mamba -powered Boulton Paul Balliol , which first flew on 24 March 1948. The Soviet Union built on German World War II turboprop preliminary design work by Junkers Motorenwerke, while BMW, Heinkel-Hirth and Daimler-Benz also worked on projected designs. While
8836-481: Was very close to what the future Rolls-Royce Trent would look like. The first British turboprop engine was the Rolls-Royce RB.50 Trent , a converted Derwent II fitted with reduction gear and a Rotol 7 ft 11 in (2.41 m) five-bladed propeller. Two Trents were fitted to Gloster Meteor EE227 — the sole "Trent-Meteor" — which thus became the world's first turboprop-powered aircraft to fly, albeit as
#817182