RAAF Lead-in Fighter – McDonnell Douglas T-45 Goshawk

The Goshawk has only three external hardpoints — one centreline and one under each wing. In US Navy service the T-45 does not have a secondary operational air defence or ground attack role and the hardpoints are intended primarily to carry training rounds for weapons training (including AIM-9 Sidewinders), external fuel tanks, a baggage pod or an air combat manoeuvring instrumentation pod.

While the structural strengthening modifications of the Goshawk for carrier operations comes at a small weight penalty — the basic empty Goshawk weighs 4460kg (9835lb) compared with 4012kg (8845lb) for the Hawk 60 and 4400kg (9700lb) for the Hawk 100 — the airframe has a fatigue life of 14,400 hours, which is being validated by a full scale fatigue test. In addition a comprehensive fatigue life data recording and tracking system monitors fleet usage. The stronger carrier capable undercarriage would also be better able to absorb punishing landings.

In the cockpit the crew sit on Martin Baker NACES zero zero ejection seats and initial production aircraft are fitted with US Navy standard instruments and radios.

As principal subcontractor British Aerospace builds the Goshawk’s wings, the centre and rear of the fuselage, the fin, tailplane, cockpit canopy and flying controls. Production Goshawks are powered by a 5845lb (26.0KN) Rolls-Royce Turboméca F405-RR-401 turbofan, a navalised development of the Adour Mk 871. Changes to the Adour to create the F405 are relatively minor and primarily revolve around modifying it for naval operations. The unmodified Adour 871 powers the Hawk 100, as offered to the RAAF by British Aerospace.

At the request of Congress, McDonnell Douglas did study re-engining the Goshawk with the AlliedSignal F124 turbofan (a development of the TFE731, an afterburning F124 powers the Taiwanese IDF lightweight fighter). Any plans to fit the Goshawk with the American engine were abandoned in January 1994, and instead the Adours fitted to the 85th Goshawk and onwards will have an increased TBO (time between overhaul).

Originally the US Navy planned to acquire 54 ‘dry’ land based T-45B Goshawks followed by 253 carrier capable ‘wet’ T-45As. In 1984 the T-45B was dropped in favour of acquiring 300 carrier capable T-45As when studies proved the feasibility of extending the service lives of the T-2s and TA-4Js. Goshawk full scale development began in 1984 with construction of the first two prototypes (by Douglas in Long Beach) beginning in 1986. 1986 also saw funding approval granted for the first 60 Goshawks and 15 flight simulators. The two full scale development prototypes both had their first flights in 1988, with the first flying on April 16. Both these aircraft were powered by a 5450lb (24.2KN) F405-RR-400L turbofan, equivalent to the Adour 861-49. Deliveries of production Goshawks was originally planned for late 1989, however this was delayed somewhat by US Navy requested modifications to the airframe and engine. These changes included the more powerful F405-RR-401/Adour 871 to combat a perceived lack of thrust in high ambient temperatures, the increased height fin and larger ventral fin to improve carrier approach handling, and the squared off wingtips and the full span leading edge slats to combat wing stall.

In December that year production and responsibility was transferred from Douglas to McDonnell in St Louis (the first St Louis built T-45 flew in December 1991 and was delivered to the US Navy early the following year). Full rate production was authorised in January 1995 and will continue through to 2005 when the USN will have taken delivery of 197 production aircraft plus the two prototypes. When delivery is complete the Goshawk fleet will be able to conduct advanced training with 42% fewer aircraft than the previous T-2/TA-4 mix with 25% fewer flight hours and with a 46% reduction in support personnel.

From 1997, McDonnell Douglas will begin delivering T-45As fitted with the ‘Cockpit 21’ advanced cockpit. The Cockpit 21 layout is a glass cockpit built on digital architecture. Centrepiece of the digital cockpit are two 127mm x 127mm (5in x 5in) Elbit monochrome multifunction displays for both crew members and a Smiths Industries HUD in the front cockpit. The multifunction displays will provide navigation, weapons delivery, aircraft performance and communications data. The HUD displays attitudinal, navigation, weapons aiming and status information. Navigation data will be courtesy of a Litton ring laser gyro linked with a Collins GPS. The Cockpit 21’s MIL-STD-1553B databus also provides the flexibility for the future integration of other avionics components.

McDonnell Douglas says that as the Cockpit 21 T-45A’s cockpit configuration, information displays and functionality closely resemble those of the F/A-18, cockpit management and operating skills learnt in the T-45 will apply directly to the F/A-18, without having to unlearn procedures learnt in a cockpit that does not adequately represent the Hornet.

The first Cockpit 21 equipped T-45 flew in March 1994 (the 37th aircraft). New build Cockpit 21 Goshawks will be delivered to the US Navy from October 1997, while earlier production Goshawks will be retrofitted with the new cockpit. One thing the US Navy standard Cockpit 21 lacks is HOTAS (hands on throttle and stick) controls, something which McDonnell Douglas is specifically developing to meet the RAAF requirement.

Aside from the T-45 itself the other important aspects of the T45TS training system programme for the US Navy are a suite of comprehensive training aids and in-depth contractor maintenance. Key elements of the training system include 19 Hughes flight simulators, 32 computer aided instructional devices, a training integration system mainframe, and 133 computer terminals. US Navy experience with the T45TS thus far has been very positive and the system has proven to be more effective and less expensive than the previous training programme.

McDonnell Douglas is offering a similar training system to the RAAF, with students becoming proficient on the Goshawk in the simulator before beginning training in the real aircraft. The company says this reduces total training costs and keeps down aircraft flying hours, thus prolonging their useful lives.

McDonnell Douglas also provides a comprehensive Contractor Logistic Support programme for the US Navy’s T-45 fleet, where it performs all operational, intermediate and depot level maintenance, spares procurement and logistic support analysis. In essence the US Navy only provides the aircraft, the instructors, and airspace. Because of this experience McDonnell Douglas should be well placed to support the RAAF’s similar requirement for its lead-in fighter support, where the winning contractor will be responsible for all but line maintenance.

If the T-45 wins the lead-in fighter requirement, through life support (Integrated Logistics Support and Contractor Logistic Support) would be provided by Rockwell Australia. Rockwell Australia and McDonnell Douglas announced their teaming covering the T-45 and its training systems for the LIF in August last year and Rockwell, through ASTA, would assemble and flight test the T-45 at Avalon if the Goshawk is selected (ASTA Defence also assembled 73 of Australia’s 75 McDonnell Douglas Hornets at Avalon during the latter 1980s).

This is the final part of our analysis of the lead-in fighter programme and the three shortlisted contenders. The RAAF is due to announce its selection late this year with entry into service planned for mid 1999.

As Forrestal Navy

The similarities between the McDonnell Douglas Goshawk and the British Aerospace Hawk from which it was derived are obvious, although the Goshawk features significant changes to the airframe and cockpit. (McDonnell Douglas)