Aircraft of the ADF-Al5 CH-47 Chinook

Shortly after the Australian order was announced, the Chinook began suffering turbine failures in the twin Lycoming T55-L-11 engines. Other alternatives considered were the adoption of the GE T64 engine of the CH-53, or the lower rated T55-L-7 of the earlier CH-47B. After delays in ready to accept the Chinook.

The first of the RAAF Chinooks (or Chooks, as they were often called) A15-001, began its air trials at the Vertol Division of Boeing in Philadelphia, USA, during June 1973, and was accepted by the RAAF on October 9. Meanwhile, No 12 Squadron had formed at RAAF Amberley on September 1 1973 to become a dedicated Chinook unit.

The twelve aircraft were serialled A15-001 to A15-012, derived from the Boeing constructor’s numbers E-001 to E-012, and had been allocated the US Army serial numbers 73-12970 to 73-12981. The Australian aircraft were known to Boeing by the model number BV-165.

The Chinooks were shipped to Australia on the RAN flag-ship HMAS Melbourne, together with five new RAAF Iroquois helicopters. These aircraft were offloaded in Brisbane in March 1974. After becoming operational in December 1974, the 12 Squadron Chinooks provided the Army with logistic support in moving fuel, artillery, ammunition, stores and troops. Aeromedical evacuation was another capability. A15-011 crashed on June 26 1975 when an engine turbine disintegrated and the aircraft made an emergency landing. The extensive damage presented a challenge to No 3 Aircraft Depot, with no previous experience in major Chinook repairs. After six years, A15-011 was finally returned to squadron service on May 21 1981.

Other varied missions for the Chinooks have been lifting Wessex helicopters for the RAN, and wrecks of wartime Boston bombers from the jungles in Papua New Guinea. Also lifted was an extremely large statue of Australian aviation pioneer Sir Lawrence Hargrave onto Mt Keira at Wollongong, typical of many tasks undertaken for the civil community.

On February 4 1985, disaster struck when A15-001 crashed into Perseverance Dam near Toowoomba resulting in the death of an RAF exchange officer. In 1986, this airframe was issued to Fire Section as a training aid.

In May 1989, the Defence Minister announced the withdrawal of the Tactical Transport Group Chinook fleet on cost grounds, and that Army Black Hawks would perform the essential roles of the Chinook. Accordingly, No 12 Squadron was disbanded on June 30 1989, with the intention of the RAAF Chinooks being sold.

It soon became obvious to the Army that the Black Hawk could not do the job of the Chinook. In late 1989, the Chinook sale was put on hold, and the option of exchanging the eleven CH-47Cs on a no-cost trade, for between four and six CH-47D models, was pursued.

The D model modernisation involves composite rotor blades, new transmissions, upgraded engines and avionics, and a rebuilt airframe providing a 30 year life extension.

On May 30 1991, the Defence Minister announced that four to six upgraded Chinooks would be obtained. The “trade-in” deal of the eleven RAAF Chinooks went ahead, but with the expense of the only four of the new D models could be afforded. The eleven aircraft were shipped back to the US in September 1993. Seven were sold to the US Army for $40m, which goes part of the way toward funding the upgrade, however, there were the added expense of spares, training and support equipment.

The “new” Chinooks are due off the production line from January through to April 1995, and will be shipped to Australia in pairs in April and July that year for operation with the Army’s 5th Aviation Regiment at Townsville. The aircraft will become fully operational during 1996 and will largely be used for pre positioning fuel and supplies, and for transporting oversize equipment.

The CH-47D Chinooks will retain the A15 prefix, but the individual numbers will alter in line with Army policy to designate a different model from the original batch. The first aircraft, ex A15-002 will become A15-102. The other three will be A15-103, A15-104 and A15-106.

Soon these Army Chinooks may not be the only ones operated in the region as Singapore is currently considering the acquisition of eight CH-47D models.