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49-453: The IPTN N-250 was a turboprop regional airliner designed by Indonesian firm IPTN ( Industri Pesawat Terbang Nusantara ) (now Indonesian Aerospace ). This aircraft was IPTN's first major effort to win the market share of the regional turboprop class of 64–68 seat airliners. The aircraft's development was eventually terminated after the Asian financial crisis of 1998. As of 21 August 2020,

98-400: 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, the compressor intake is at the aft of the engine, and

147-415: 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 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

196-598: A Boeing 737-500 aircraft equipped with 120 seats in two classes. Upon its launch, NAM Air became the first airline to allow its female flight attendants to use a hijab as part of their uniform on any given flight. NAM Air was included in the EU airline blacklist of carriers that did not meet necessary safety standards to fly to airports in the European Union, and was thus banned from operating in European airspace. It

245-520: 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 was very close to what

294-615: A capacity of 64–68 passengers, and it was designated as the N250-100. The N250-100 was planned to have its first flight in May 1996, but the PA-2 prototype instead had its initial flight eight months behind schedule on 19 December 1996. The third and fourth prototypes were planned to first fly in July 1996 and September 1996 respectively. Construction for the additional prototypes was halted because of

343-442: 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 the model, such as an overspeed and fuel topping governor on

392-502: A memorandum of understanding with Leonardo Aerostructures to help fund and complete the development of the R-80. The company hoped to build four hundred R-80 aircraft over 20 years. It completed a preliminary design and feasibility test of the 80-90 seat aircraft in 2016 and hoped to finish detail designing and prototype manufacturing by 2019. RAI planned to build six prototypes, with flight testing from 2020 to 2022, and targeted issuance of

441-410: 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 the way down to zero pitch, producing very little to zero-thrust and

490-487: A reduction in engine capacity, and the removal of the fly-by-wire system. The planned reborn plane was planned to be named N250R. In August 2012, both developing parties, Erry Firmansyah of PT Eagle Cap and PT Regio Aviasi Industri (RAI), led by both of Habibie's sons, agreed to finance N-250. It will use a new name, R-80. On 26 September 2013, Nam Air signed an order for 50 R-80 with an option for 50 more aircraft, to be delivered in 2018. On 22 February 2018, RAI signed

539-520: A risk-sharing partner to help complete the program. There has been some consideration concerning the program's revival by the former director of the IPTN and, later, the former Indonesian president B. J. Habibie after having received approval from the incumbent president Susilo Bambang Yudhoyono . However, to reduce production costs and improve price competitiveness in international markets, changes were made which have resulted in reduced performance such as

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588-581: 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 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

637-591: 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

686-673: A type certificate from the European Aviation Safety Agency (EASA) in 2025. The price of the R-80 would be USD$ 25 million. B. J. Habibie's son, Ilham Akbar Habibie, advocated for the production of the aircraft as one of its competitors, the Fokker 50 , was no longer produced by Fokker which went bankrupt in 1996. The remaining two competitors for the N-250 were the ATR 72 and Bombardier Dash 8 . Data from Jane's all

735-402: 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 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

784-407: 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 the gas generator section, many turboprops today feature a free power turbine on a separate coaxial shaft. This enables

833-421: 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 the pilot not being able to see out of the rear of the aircraft for backing and

882-595: The Allison GMA 2100 turboprop to power the aircraft. In early 1994, Indonesia announced that Great Britain and four states in the United States were interested in hosting production lines for the final assembly of the N-250. In January 1995, IPTN added Long Island, New York and Macon, Georgia to the previous list of U.S. semifinalists that included Mobile, Alabama , Phoenix, Arizona , and Portland, Oregon , out of an original list of 26 contender cities. In

931-634: 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

980-841: 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

1029-614: 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,

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1078-403: 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 a constant-speed propeller increase their pitch as aircraft speed increases. Another benefit of this type of propeller

1127-587: The Mobile factory. The flying aircraft was officially unveiled at the Indonesian Air Show '96, and it also performed at the 1997 Paris Air Show and the 1998 Asian Aerospace show. The first assembled prototype, which had a capacity of 50 passengers, was initially rolled out on 10 November 1994 in Bandung during the run-up to the 1994 Asia-Pacific Economic Cooperation (APEC) summit, which Indonesia

1176-537: The PA-1 prototype is on display at Dirgantara Mandala Museum , Yogyakarta, as its 60th collection. The N-250 development plan was first revealed by PT IPTN (now PT Dirgantara Indonesia, Indonesian Aerospace ) at the Paris Air Show in 1989, but was first introduced in 1986 when the Indonesian Air Show 1986 was held. The N-250 was initially described as a propfan commuter plane, but on 12 July 1990, IPTN selected

1225-533: 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

1274-590: The World's Aircraft . 2005–2006. Nam Air The creation of NAM Air was announced on 26 September 2013, originally envisioned as a full-service subsidiary for the Sriwijaya Air Group that was to compete with the Indonesian state-owned flag carrier, Garuda Indonesia and Lion Air Group 's Batik Air . The airline's inception was announced by Sriwijaya Air President, Chandra Lie, who dedicated

1323-409: The World's Aircraft 2000–01 General characteristics Performance Related development Aircraft of comparable role, configuration, and era Turboprop A turboprop 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

1372-400: The airline in the name of his father, Lo Kui Nam. The airline's full service intentions was later scrapped in favour of being a feeder carrier to Sriwijaya Air, akin to the relationship between Wings Air and Lion Air ; under this arrangement, Sriwijaya Air would serve mainline routes, whereas NAM Air would operate secondary routes not targeted by its parent. Following the announcement,

1421-601: The airline planned on launching its maiden flight in October 2013. The launch was later postponed due to the pending issuance of the carrier's Air Operator's Certificate (AOC) by the Indonesian Ministry of Transportation . NAM Air acquired its AOC on 29 November 2013 and flew its first testing flight from Jakarta to Pangkal Pinang on 11 December 2013. On 19 December 2013, the airline operated its maiden commercial flight from Jakarta to Pontianak to Yogyakarta with

1470-414: 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 the control system. The turboprop system consists of 3 propeller governors ,

1519-612: The effects of the Asian financial crisis . Although the IPTN was about halfway through its 1,400-hour flight test program, the International Monetary Fund (IMF) required the Indonesian government to end support of the N-250 program as part of the IMF's US$ 43 billion government bailout plan. Because of this event, IPTN postponed the aircraft's certification from March 1999 to the fourth quarter of 2000. Later, IPTN postponed certification indefinitely so that it could recruit

IPTN N-250 - Misplaced Pages Continue

1568-407: 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 a large amount of air by a small degree than

1617-499: 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

1666-564: 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

1715-468: The following month, IPTN selected Mobile and Macon as the final candidates. On May 19, 1995, Indonesia awarded the U.S. assembly of the N-250 to Mobile. The U.S. assembly site would be run by American Regional Aircraft Industry (AMRAI), in which IPTN would hold a 40-percent stake. Planned production was to be one plane per week from IPTN's home factory in Bandung, West Java and up to two planes per week from

1764-465: 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

1813-623: 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

1862-493: 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 is normally a constant-speed (variable pitch) propeller type similar to that used with larger aircraft reciprocating engines , except that

1911-534: 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 the gas power produced by the engine for jet thrust. The world's first turboprop

1960-403: 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 is the mode for all flight operations including takeoff. Beta,

2009-592: 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

IPTN N-250 - Misplaced Pages Continue

2058-406: 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 the propulsion airflow is less clearly defined for propellers than for fans. The propeller is coupled to

2107-475: 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 the propeller. This allows for propeller strike or similar damage to occur without damaging the gas generator and allowing for only

2156-573: 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, was produced and tested at the Ganz Works in Budapest between 1937 and 1941. It

2205-405: Was hosting. This prototype, which had a serial number of PA-1, then flew for the first time on 10 August 1995. It was successfully tested to a cruise speed of 727.8 kilometers per hour (452.2 mph; 393.0 kn) at 7,600 meters (25,000 ft) altitude, and 744.5 km/h (462.6 mph; 402.0 kn) at 5,200 m (17,000 ft) altitude. The second prototype was a stretched variant with

2254-467: 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 was destroyed in

2303-714: 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

2352-454: Was removed from the blacklist, along with every other Indonesian airline in June 2018. On 8 November 2018, NAM Air and its parent, Sriwijaya Air, entered a cooperation agreement with Garuda Indonesia, effectively taking over the operations and financial management of both airlines through its subsidiary, Citilink Indonesia . The agreement was made in order to facilitate the financial recovery of

2401-603: 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

#1998