Aussie Thunderstreaks

**Spinners** · May 3, 2015

Republic F-84M Thunderstreak - No.1 Squadron, Royal Australian Air Force, 1964

The swept-wing Republic F-84F Thunderstreak was an important fighter-bomber for the United States and her NATO allies and after a troubled development and delays in production the Thunderstreak programme soon recovered and, with massive orders to fulfill, the Farmingdale production line was supplemented by a second production line outsourced to General Motors at Kansas City. When the last straight-winged F-84G Thunderjet rolled off the Farmingdale production line on July 27th, 1953 production of the newer aircraft stepped up sharply and was boosted by the employment of several subcontractors including Kaiser Metal Products, Servel and Goodyear Aircraft.

Republic Aviation then started a self-financed project to replace the F-84F and RF-84F family and Alexander Kartveli's design team settled on a large, single-engined fighter-bomber initially known as the AP-63FBX (Advanced Project 63 Fighter Bomber, Experimental) but later to become the legendary F-105. Designed primarily for supersonic, low altitude penetration the F-105 was capable of delivering a single nuclear bomb carried in a small internal weapons bay and an enthusiastic United States Air Force soon rewarded Republic with a production order contract for 199 aircraft in September 1952. However, the expected end of the Korean War forced the United States Air Force to reduce their order to just 46 aircraft before cancelling the entire programme at the end of 1953 but then reinstating the programme in June 1954 with a small order for 15 F-105 aircraft (two YF-105A's, four YF-105B's, six F-105B's and three RF-105B's).

Faced with such uncertainty, Republic Aviation looked at ways of keeping the F-84F in production and focused on tackling the F-84F's mediocre flight performance and especially the poor takeoff performance with a more powerful engine. Kartveli quickly dusted down a previous study of fitting the Rolls-Royce Avon engine into the F-84F and with this fine engine being of a similar size as the Sapphire/J65 but now rated at 10,000lbs of dry thrust Kartveli looked no further than an F-84F modified to accept the Avon engine. The new version also incorporated several refinements learned from service experience such as stainless steel control rods and an improved all-flying tail that almost removed the vicious stall characteristics of the F-84F. Designated by Republic Aviation as the F-84M the new aircraft was marketed aggressively as a dedicated tactical fighter-bomber and soon picked up orders from Canada, New Zealand and Australia with the latter operating their F-84M's in action over Vietnam in 1964 and 1965.