A clash of generations: the key question in advanced jet trainers is whether new designs should now take over, thereby providing a quantum leap in angle-of-attack, specific excess power and possibly Mach number. Lower down the scale, can turbofan-powered basic trainers really compete against turboprops?
Military fixed-wing training aircraft are discussed below as four distinct categories: piston/rotary-engined primary trainers, turboprop basic trainers, turbojet/turbofan basic trainers and advanced trainers.
The purpose of the primary training or screening is to quickly identify students who will probably not complete the syllabus in a reasonable time. This is traditionally argued to require an engine of around 200 kW and more difficult handling characteristics than a civil trainer.
Such aircraft are undoubtedly suitable for screening university graduates, but it is arguable that air forces with lower entry standards should consider less demanding civil trainers, such as America's 600-kg Light Sport category. Examples include the Cessna LSA (which has been flying since October 2006 and was given the go-ahead in 2007 and is now called the Model 162 SkyCatcher) and the Sport Aircraft Works SportCruiser. The latter is built by the Czech Aircraft Works, and is listed at only $ 74,500 with a 75-kW Rotax 912ULS engine, or $ 78,000 with a 90-kW Jabiru 3300.
Higher up the weight scale are the 750kg Diamond Aircraft DA20 Katana (as used in DA20C1 form with 93 kW Teledyne Continental engine for screening for the US Air Force) and the Hansa-3. The latter was developed by India's National Aerospace Laboratories and is produced by Taneja Aerospace and Aviation. The baseline DA20 and Hansa-3 are both powered by 75-kW Rotax engines.
Civil trainers tend to be lightly stressed, but the New Zealand-based Alpha Aviation has acquired from Apex International (owners of Robin Aviation) global rights to the Robin HR200 and R2000 series, stressed to +6G. The baseline trainer is the R2120-based Alpha 120T with a 90-kW Textron Lycoming, while the R2160-based Alpha 160 has a 120-kW unit.
In a more traditional military category, Pacific Aerospace has recently unveiled the 225-kW CT-4F, developed by Raytheon Australia and equipped with multi-function displays and the mission system from the Beechcraft T-6B. The CT-4F is aimed at the lower component of Royal Australian Air Force Project Air 5428. This will combine a new primary trainer, replacing contractor-operated Eads/Socata TB10s from perhaps 2010, and a new basic trainer, replacing the RAAF PC-9/A from 2012.
Few manufacturers can survive on sales of trainers alone. Germany's 194kW Grob G120A, which is now contractor-operated for the services of Canada, France and Israel, is only one element of a very successful family. Grob has sold over 400 G 115/120s. The widely used T67 Firefly is likewise only one of Slingsby Advanced Composites' many products ranging across aerospace, defence and maritime sectors.
A really good trainer can be sold almost indefinitely. Sweden's MFI-17 first flew in 1971, was manufactured by Saab as the Safari/Supporter, and is now built as the Mushshak (Urdu for 'proficient') by the Aircraft Manufacturing Factory of the Pakistan Aeronautical Complex. The baseline Mushshak retains the 149-kW Textron Lycoming, while the Super Mushshak has a more powerful (194 kW) version.
In March 2006 Turkey's Undersecretariat for Defense Industries contracted Tusas Aerospace Industries (TAI) to develop a Primary and Basic Trainer Aircraft to be named 'Hurkus' after the country's pioneer aviator Vecihi Hurkus. Two static test vehicles and two flying prototypes are to be built.
The primary trainer category will benefit from the introduction of diesel engines capable of burning avtur (aviation turbine) fuel. Thielert Aircraft Engines took the lead when its 100-kW Centurion 1.7 became standard equipment for the Diamond Aircraft DA42 in 2001. Now produced as the Centurion 2.0, this engine is approved for 25 aircraft types, and over 1500 examples have been manufactured. The 260-kW Centurion 4.0 is also available.
Since the 1960s a whole generation of basic jet trainers has been replaced with turboprop-powered aircraft. In essence, it is far more economical in terms of both flyaway price and operating cost to replace a turbojet with a smaller turbine engine, employing a propeller as a thrust-augmentor.
However, trainers at the lower end of the turboprop range have had little success. Siai-Marchetti (now taken over by Alenia Aermacchi) has sold only 50 SF-260TPs (and twelve conversion kits), compared to 707 military and 125 civil piston-engined SF-260s. The new owner has withdrawn the M-290TP Redigo from its product range.
The major turboprop trainer players have been Pilatus with the PC-7 and PC-9 and Embraer with the Tucano, both series using Pratt & Whitney Canada PT6 engines. Pilatus, which has delivered over 800 such trainers to 32 air forces, teamed with Raytheon to win the Pentagon's Jpats (Joint Primary Aircraft Training System) contest, resulting in the PC-9-based Beechcraft T-6 Texan II.
The potential Jpats market is for 454 T-6s for the US Air Force and 328 for the US Navy. Over 450 T-6s have already been delivered. The US FY08 budget request is for 39 for the US Air Force and 44 for the US Navy, indicating a domestic unit cost of $ 6.65 million with spares. The T-6A has been exported to Canada (26 for NFTC) and Greece (45).
Starting in 2009 the US Navy plans to have 283 Texans completed to T-6B standard, with upgraded avionics by CMC Electronics, including 'glass' cockpits with a Hud in the front. The $ eight million AT-6B is a light-attack development of the T-6B with a new mission computer and provisions for a ventral sensor turret, cockpit armour, a datalink and light weapons. A variant with external tanks and Raytheon AIM-9X air-to-air missiles has been offered for US homeland security, to replace the fighters protecting 15 cities from repeats of 9/11.
Press reports indicate that up to 50 AT-6Bs may be acquired via the US Air Force for the Iraqi Air Force. This Coin requirement calls for the first of a batch of eight aircraft to be delivered in November 2008 and the last by April 2009, with the option of subsequent six-aircraft batches. The cockpit and engine are to be lightly armoured, and the aircraft must be able to carry EO/IR sensors and laser-guided air-to-ground weapons.
Acknowledging its inability to compete in the international market against the political clout behind the T-6, Pilatus has developed a completely new trainer, the PC-21, in a higher performance category. Powered by an 1195-kW P&WC PT6A-68B, the PC-21 was probably aimed initially at the UK requirement for a Tucano replacement. While waiting for the British decision, Pilatus has recorded PC-21 sales to Singapore (21) and Switzerland (six). It is planned that the PC-21 will take Swiss Air Force pilots directly to the Boeing F/A-18C/D.
If the Shorts-built Tucano is included, approximately 650 Tucanos have been manufactured for 17 air forces. Embraer is now producing the EMB-314 Super Tucano with a stretched fuselage, a pressurised cockpit and a 970-kW P&WC PT6A-68A engine. It formed the basis for the ALX programme for the Brazilian Air Force, to provide basic flying training and close air support. The initial order was for 25 single-seat A-29s and 51 two-seat AT-29s, with an option on 23 more A-29s. The sale of Super Tucanos to Venezuela was stopped by Washington, but the aircraft has been sold to Colombia (25, specifically for light attack) and selected by the Dominican Republic.
Korea Aerospace Industries (KAI) has built 85 KT-1 basic trainers and 20 light-attack KO-1s for the Republic of Korea Air Force, both types equipped with the 708-kW P&WC PT6A-62A engine. Twelve KT-1Bs have been ordered for the Indonesian Air Force. In late 2006 KAI signed an agreement with Indonesian Aerospace (PT Dirgantara Indonesia), licensing the latter to produce the KO-1. The KT-1C with a glass cockpit by CMC Electronics was due to fly around the end of 2006, and to be available by 2010. KAI plans a Super KT-1 with enhanced engine and avionics for delivery around 2015.
In July 2007 Turkish Aerospace Industries signed an agreement with KAI for license-manufacture of the KT-1. This is expected to lead to the production of 40 aircraft for the Turkish Air Force, with an option on 15 more.
In early 2007 it was revealed that US Aircraft is collaborating with Brazil's Geometra on a tandem-seat, turboprop, light-attack aircraft similar in configuration to the Tucano and powered by a 930-kW PT6A-68. It reportedly retains the name of the former company's A-67 Dragon, which had side-by-side seating and crashed at the end of its maiden flight in October 2006.
The 1950s produced some highly successful jet-powered basic trainers, notably the Cessna T-37, which first flew in 1954. The Aermacchi MB-326 followed in 1957 and the Aero Vodochody L-29 in 1959.
The availability of turbofans from the 1960s raised the possibility of a new generation with much longer endurance, but the only major success was the Aero Vodochody L-39, which flew in 1968. In the absence of a Warsaw Pact turboprop trainer, over 2800 L-39s were built.
In the late 1970s the US Air Force issued a requirement for a T-37 replacement, and in 1982 selected the Fairchild Republic T-46A with two Garrett TFE76 turbofans. However, the T-46A had development problems, and in 1987 was abandoned.
Attempting to repeat the success of its piston-engined SF-260 primary trainer, which sold to 27 air forces, Siai-Marchetti developed the S-211, combining an 11.12-kN P&WC JT15D-4C turbofan with a supercritical wing (designed with Boeing assistance). The S-211 flew in 1981 and appeared to have everything going for it, but only 58 were built. Singapore bought 30 and the Philippines 19. For some observers, this was proof that turbofan-powered basic trainers cannot compete with turboprops.
Despite the S-211 experience, Alenia Aermacchi took over Siai-Marchetti, continuing production of the piston-engined SF-260 (a batch of 30 SF-260EAs is being built for the Italian Air Force) and launched development of the M-311, effectively an S-211 with a 14.23-kN JT15D-5C and 'Cockpit 4000' by CMC Electronics.
If a turbofan basic trainer is to succeed it needs a major launch customer. One such project is the Hindustan Aeronautics (Hal) IJT-36 Sitara (Morning Star), which has a potential domestic market of 211 aircraft, including 24 for the Indian Navy. The IJT-36 began flight trials in 2003 with the GRTS Larzac engine, but the production version will have the Hal-built 17.8-kN Saturn AL-55I. Deliveries will begin in 2009.
On the subject of new turbofans, Aero Vodochody has plans for a modernised L-39 with European avionics and a 27.7-kN Ivchenko-Progress AI-228-28, to circumvent the US embargo on sales of the Honeywell F124-equipped L-159 to countries such as Venezuela.
Digressing briefly, most L-159s were built as single-seaters (L-159As) for the Czech Air Force, and have so far proved un-sellable elsewhere, although Nigeria may buy around a dozen. The only successful single-seat version of a jet trainer was the Aermacchi MB-326K. The MB-339K and BAE Systems Hawk 200 are no longer marketed.
One basic jet trainer with a large potential domestic market is the Hongdu/Pac JL-8 or K-8 (export designation), which was jointly developed by China and Pakistan and first flew in 1990. Pakistan may eventually acquire up to 100 K-8s with Honeywell TFE731s. The JL-8 is thought to have the Progress AI-25TLK or a Chinese copy, the WS-11. China's Avic-II group is believed to have sold at least 226 K-8s to more than ten air forces. The principal user is Egypt, which has manufactured 80 K-8Es.
The Javelin Mk 20, developed by Colorado-based ATG (Aviation Technology Group) with some assistance from IAI/Lahav, is powered by two 7.56-kN Williams FJ33-4 engines.
In recent years the BAE Systems Hawk has enjoyed a virtual monopoly of the advanced trainer market, with significant wins in South Africa and India. There are 22 Hawk users around the world, and the series is now available with the uprated 29-kN Rolls-Royce Adour 951, and with radar and weapons simulation. Deliveries of the improved Hawk 128 to Britain's RAF begin in August 2008.
The Boeing T-45A/C Goshawk carrier-capable derivative of the Hawk has so far made no impact on the export market, but is being offered to the Indian Navy, whose MiG-29K pilots train on US Navy T-45s. The US Navy plans an eventual total of 233 T-45s, of which the 200th was delivered in March 2007. There is no provision for production in the Pentagon's FY08 budget, but $ 91 million is requested for modifications and upgrades.
A new generation of advanced trainers is approaching maturity, the European leader being the Aermacchi M-346, developed from the Yakovlev Yak-130 and powered by two 28-kN Honeywell F124 turbofans. The first of two prototype M-346s flew in 2004, and the first pre-series aircraft is to be rolled out before the end of 2007. Having twice as much thrust as a Hawk, the M-346 must be expensive, but will provide better war-load-radius performance in operational roles. In the training role, it offers higher specific excess power and angle-of-attack and (at a later stage) handling characteristics that can be changed to simulate different operational aircraft.
The eleven-nation Eurotraining programme currently appears likely to be launched as three or four regional groupings. Italy's Ministry of Economic Development has recently announced that it will provide [euro] 200 million for a preliminary batch of 14 M-346s. This is hoped to encourage procurement by the United Arab Emirates and pave the way for a multi-national training programme based in Italy, using the M-346.
Despite the crash of the third prototype Yak-130 in July 2006, the Russian Air Force has placed a firm order for an initial batch of twelve aircraft out of a planned 60 and a long-term total of 250. Algeria has ordered 16 for training and light attack duties, and Irkut has referred to a total of 82 further orders. The Yak-130 is powered by two 24.5-kN Salyut-built Ivchenko-Progress AI222-25 turbofans.
Although it lost the Russian Air Force contest to the Yak-130, the MiG-AT is being offered to India with two of the Saturn AL-55I engines planned for the IJT-36. The MiG-AT prototypes were powered by two Larzac engines, but one is being flown with one Larzac and one AL-55I, the latter rated at 16.9 kN. Hindustan Aeronautics has its own HJT-39 advanced trainer project, with two 22.24-kN AL-55Is.
In the absence of support for its supersonic Mako project, Eads reportedly favours the KAI T-50 Golden Eagle for the Eurotraining programme. Developed with help from Lockheed Martin and powered by a 78.5-kN afterburning General Electric F404, the first T-50 flew in 2002. Some 72 T-50s have been ordered by the South Korean Air Force, and student instruction began in April 2007. The FA-50 is a light attack derivative, of which South Korea may buy up to 60.
China's Mach 1.6 Guizhou/Avic-I JL-9 or FFC-2000 is a derivative of the MiG-21UTI with lateral intakes. It first flew in December 2003 and manufacture of a pre-series batch reportedly began in May 2007. It is competing with the more modern Hongdu/Avic-II JL-15, which was designed with assistance from Yakovlev and resembles the Yak-130. The JL-15 first flew in March 2006. It is currently powered by two Ivchenko-Progress AI-222-25 engines but will later have 41-kN afterburning AI-222FKs, which are hoped to produce a speed of Mach 1.4. The Plaaf is due to decide between the two in late 2007.