FLUG REVUE October 2003: KAI T-50 testing continues

KAI T-50 TRAINER: TESTS MOVE AHEAD

By Karl Schwarz

On 28 July, the T-50 Golden Eagle faced the real test at last: after over 100 development test flights with the first two prototypes of the jet trainer, regular pilots from the Republic of Korea Air Force (ROKAF) were sitting in the cockpit for the first time for the Initial Operational Assessment. Testing of the suitability of the new type for advanced training through to the transition to operational aircraft was conducted until August 14.

KAI T-50 in flight

“We know that we have a sound, reliable aircraft,” said Colonel Lee Hee Woo of ROKAF confidently at the beginning of the trials. Now it was a matter of examining the handling and performance parameters of the aircraft developed by Korea Aerospace Industries (KAI) on typical training flights. What are the landing characteristics, how well can the instructor in the back seat monitor the student, how simple are the systems to operate – these and similar questions needed to be answered.

The IOA report is one of three preconditions that have to be satisfied before the government in Seoul will signal the go-ahead for production, expected in October. The necessary number of flying hours had already been achieved in June, and the assessment of the integrated logistics programme was favourable. “We are very pleased with progress on the programme. So far there have not been any major problems and the schedule has been met in every respect,” said Ahn Taek Soon, vice president for strategic business development at KAI.

Lieutenant Colonel Cho Gwan Je, ROKAF's chief T-50 test pilot, also spoke positively about the trainer recently. “The T-50 is great to fly and it handles very well in the flight envelope tested so far. Our student pilots should get used to the aircraft very quickly.”

Cho Gwang Je should know, as he has flown more hours on the T-50 than anyone else to date. It was he who was at the controls of the Golden Eagle during its maiden flight in Sachon on 28 August 2002. This entailed carrying out the first handling tests, initially at an altitude of 2,130m and then at 4,570m, before bringing the aircraft in to land after 39 minutes. The maximum angle of attack on that flight was 13 degrees and the maximum speed 450 km/h.

Cho Gwang Je also conducted the first flight of the second test aircraft on 8 November 2002. On that occasion he flew a similar programme to the maiden flight of the first prototype, remaining in the air for 47 minutes. The second prototype has additional instrumentation for the measurement of flight loading and accurate recording of engine parameters. It also has a digital camera system and a parachute as protection during spin trials.

At the end of November Cho Gwang Je took the T-50 up to its operational ceiling of over 14,000m for the first time. There he carried out flutter tests at Mach 0.6. By this time 24 flying hours had been logged. “The flight test programme was designed to have a somewhat slow start,” explained Tom Ryan of Lockheed Martin, sent out to Sachon to act as adviser. “Flight tests with a jet are new for the team of KAI technicians and the military. Besides, during the monsoon period the weather can be quite dreadful here.”

By mid-February 2003, the number of flying hours had risen to over 60. Then on 19 February the T-50 went supersonic for the first time with Major Choong Hwan Lee at the controls. With the General Electric F404-GE-102 operating at full afterburner power, a speed of Mach 1.05 was achieved at an altitude of 12,190m and then maintained for around a minute with afterburner set to minimum. Since then the aircraft has been flown at Mach 1.2.

The two remaining pre-series aircraft were scheduled to take to the air in the late summer. The test programme, using a total of 4 Golden Eagles, is then due to run to the end of 2005. “We could complete testing of the trainer version in 18 months,” explained Craig Lawrence of Lockheed, “but 60 percent of the programme is to be carried out on the LIFT [Lead-in Fighter Trainer] version, with radar, cannon and weapons plus the associated avionics. We also have to conduct weapons tests.”

If everything goes smoothly, the T-50 will enter service with ROKAF at the end of 2005. The 3rd Air Wing, which is responsible for the training, has its hangar right on the opposite side of the runway in Sachon from the KAI manufacturing facility. The Golden Eagle is expected to cover a major part of the training programme, thus replacing the BAE Hawk, T-38 Talon and F-5B Tiger in service up to now. For its ab initio training, ROKAF is currently procuring the turboprop trainer KT-1 Wong Bee, also from KAI. This will replace the Cessna T-41 Mescalero and the T-37 jet.

“The T-50 should be viewed as a training system,” explains No Sun Park, plant manager in Sachon. “This includes dome simulators, cockpit trainer, maintenance trainer, theoretical training with computer support and a comprehensive management system for the instructors, including an evaluation system.”

“Air forces all over the world want a complete training package,” says Park. This is also the view of Lockheed Martin. The US defence giant is funding 13 percent of the development costs and is helping KAI with the international marketing. The Koreans are optimistically hoping to export 600 Golden Eagles. However, this figure presupposes that USAF replaces its T-38's with the T-50.

At the Paris Air Show in June it was said that the company was in discussion with potential customers in the Middle East, Asia and Eastern Europe. As far as costs are concerned, the programme is fully competitive. The aircraft itself is expected to sell with a price tag of $18-20 million. This is between $3 and $5 million more expensive than, for example, an M-346 from Aermacchi. However, the T-50 also offers supersonic flight. The value of this during training is disputed, so it will be interesting to see which trainer is the most successful over the next few decades.

Korean prestige programme

The T-50 is the first jet aircraft to have been developed in South Korea and is thus an important element of that country's ambitions to expand its aerospace industry. Feasibility studies for the development of a high-performance jet trainer designated the KTX-2 were carried out in 1992, at that time by Samsung. The company was supported in this under an offset agreement, following the purchase of F-16's from General Dynamics in Fort Worth.

By mid-1995 a basic design for the KTX-2 had been developed, but then the programme had to be suspended as the government was not in a position to provide further funding. It was not until Lockheed Martin came onboard after a prolonged search for a partner that the government officially gave the programme the green light on 3 July 1997. Two years later, Samsung Aerospace, Daewoo Heavy Industries and Hyunday Space and Aircraft merged into Korea Aerospace.

After 4,800 hours of wind tunnel testing, the aircraft, renamed the T-50 Golden Eagle, passed the critical design review in August 2000. Final assembly commenced on 15 January 2001 with the assembly of three fuselage segments. Then in June Lockheed Martin delivered the wings, in time for the roll-out celebration to take place on 31 October 2001 in the presence of President Kim Dae-jung.

As one would expect, given the influence of Fort Worth, the T-50 looks like an F-16 shrink. It has variable-camber wings; however, these are somewhat thicker than on the US fighter. The control surfaces are relatively larger so as to give sufficient control authority. Naturally the installation includes a digital flight control system (FADEC).

Once again, the cockpit resembles the F-16, with two large colour displays to the side and a head-up display. On the other hand, the sidesticks are movable, so that the instructor can feel the inputs of the student pilot.

The powerplant selected was the tried and trusted F404 from General Electric. When it came to the systems, extensive use was made of equipment already available from well-known manufacturers such as Martin-Baker, BAE Systems, Smiths Industries, Honeywell and Raytheon.

The airframe design is somewhat conventional. It was optimised with the aid of a CATIA system. Thus, for example, the centre fuselage initially consisted of three parts, which were then reduced to two. “We had to draw up plans for 12,000 parts,” recalls plant manager No Sun Park. “Thanks to the computer design, the changes were relatively trivial. We did not build a single mock-up. Everything was done on the computer.”

Performance-wise, the T-50 should approach the agility and acceleration capability of current and future fighter aircraft. As well as the basic version, a LIFT version is also to be built. This will prepare students specifically for the operational types. For this purpose, an APG-67 radar is to be installed. Armaments will comprise cannon, bombs and missiles. Such an aircraft can then be marketed as a light combat aircraft (A-50).

From page 44 of FLUG REVUE 10/2003

Last updated 1 September 2003

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