The history
Development
In 1949, a swept wing version of the F-84 was created with the hope of bringing performance to the level of the F-86. The last production F-84E was fitted with a swept tail, a new wing with 38.5 degrees of leading edge sweep and 3.5 degrees of anhedral, and a J35-A-25 engine producing 5,300 pound-force (23.58 kN) of thrust. The aircraft was designated XF-96A. It flew on 3 June 1950 with Otto P. Haas at the controls. Although the airplane was capable of 602 knots (693 mph, 1,115 km/h), the performance gain over the F-84E was considered minor. Nonetheless, it was ordered into production in July 1950 as the F-84F Thunderstreak. The F-84 designation was retained because the fighter was expected to be a low-cost improvement of the straight-wing Thunderjet with over 55 percent commonality in tooling.
YF-84F and YRF-84F prototypes in 1952.
In the meantime, the USAF, hoping for improved high-altitude performance from a more powerful engine, arranged for the British Armstrong Siddeley Sapphire turbojet engine to be built in the United States as the Wright J65. To accommodate the larger engine, YF-84Fs with a British-built Sapphire as well as production F-84Fs with the J65 had a vertically stretched fuselage, with the air intake attaining an oval cross-section. Production delays with the F-84F forced the USAF to order a number of straight-wing F-84Gs as an interim measure.
Production quickly ran into problems. Although tooling commonality with the Thunderjet was supposed to be 55 percent, in reality only fifteen percent of tools could be reused.[ To make matters worse, the F-84F utilized press-forged wing spars and ribs. At the time, only three presses in the United States could manufacture these, and priority was given to the Boeing B-47 Stratojet bomber over the F-84. The YJ65-W-1 engine was considered obsolete and the improved J65-W-3 did not become available until 1954. When the first production F-84F finally flew on 22 November 1952, it differed from the service test aircraft. It had a different canopy which opened up and back instead of sliding to the rear, as well as airbrakes on the sides of the fuselage instead of the bottom of the aircraft. The aircraft was considered not ready for operational deployment due to control and stability problems. The first 275 aircraft, equipped with conventional stabilizer-elevator tailplanes, suffered from accelerated stall pitch-up and poor turning ability at combat speeds. Beginning with Block 25, the problem was ameliorated by the introduction of a hydraulically powered one-piece stabilator. A number of aircraft were also retrofitted with spoilers for improved high-speed control. As a result, the F-84F was not declared operational until 12 May 1954.
Thunderflash
RF-84F Thunderflash, the reconnaissance version of the F-84F.
The second YF-84F prototype was completed with wing-root air intakes. These were not adopted for the fighter due to loss of thrust. However, this arrangement permitted placement of cameras in the nose and the design was adopted for the RF-84F Thunderflash reconnaissance version. The first YRF-84F was completed in February 1952. The aircraft retained an armament of four machine guns and could carry up to fifteen cameras. Innovations included computerized controls which adjusted camera settings for light, speed, and altitude, a periscope to give the pilot better visualization of the target, and a voice recorder to let the pilot narrate his observations. Being largely identical to the F-84F, the Thunderflash suffered from the same production delays and engine problems, delaying operational service until March 1954. The aircraft was retired from active duty in 1957, only to be reactivated in 1961, and finally retired from the ANG in 1972.
Several modified Thunderflashes were used in the FICON project.
Design
The Thunderstreak suffered from the same poor takeoff performance as the straight-wing Thunderjet despite having a more powerful engine. In reality, almost 700 pounds-force (3.11 kN) or ten percent of total thrust was lost because the J65 was installed at an angle and its exhaust had a prominent kink. On a hot day, 7,500 feet (2,285 m) of runway were required for takeoff roll. A typical takeoff speed was 160 knots (185 mph, 300 km/h). Like the Thunderjet, the Thunderstreak excelled at cruise and had predictable handling characteristics within its performance envelope. Like its predecessor, it also suffered from accelerated stall pitch-up and potential resulting separation of wings from the airplane. In addition, spins in the F-84F were practically unrecoverable and ejection was the only recourse below 10,000 feet (3,000 m).
Operational history
A USAFE F-84F from the 91st TFS at RAF Bentwaters.
An Ohio Air National Guard F-84F in the late 1960s
F-84F Thunderstreaks flown by USAF Thunderbirds
F-84F
Project Run In completed operational tests in November 1954 and found the aircraft to be to USAF satisfaction and considerably better than the F-84G. However, ongoing engine failures resulted in the entire fleet being grounded in early 1955. Also, the J65 engine continued to suffer from flameouts when flying through heavy rain or snow. As the result of the problems, the active duty phaseout began almost as soon as the F-84F entered service in 1954, and was completed by 1958. Increased tensions in Germany associated with construction of the Berlin Wall in 1961 resulted in reactivation of the F-84F fleet. In 1962, the fleet was grounded due to the corrosion of control rods. A total of 1,800 man hours were expended to bring each aircraft to full operational capacity. Stress corrosion eventually forced the retirement of ANG F-84Fs in 1971.
On 9 March 1955, Lt. Col. Robert R. Scott, in a F-84F Thunderstreak, set a three-hour, 44-minute and 53-second record for the 2,446 mile flight from Los Angeles to New York.
With the appearance of the Republic F-105 Thunderchief, which also used wing-root mounted air intakes, the Thunderstreak became known as the Thud's Mother. The earlier F-84A had been nicknamed the "Hog" and the F-84F "Super Hog," the F-105 becoming the "Ultra Hog".
In what is probably one of the very few air-to-air engagements involving the F-84F, two Turkish Air Force F-84F Thunderstreaks shot down two Iraqi Il-28 Beagle bombers that crossed the Turkish border by mistake during a bombing operation against Iraqi Kurdish insurgents. This engagement took place on 16 August 1962.
The F-84F was retired from active service in 1964, and replaced by the North American F-100 Super Sabre. The RF-84F was replaced by the RF-101 Voodoo in USAF units, and relegated to duty in the Air National Guard. The last F-84F Thunderflash retired from the ANG in 1971. Three Hellenic Air Force RF-84Fs that were retired in 1991 were the last operational F-84s.
General characteristics
Crew: 1
Length: 43 ft 4¾ in (13.23 m)
Wingspan: 33 ft 7¼ in (10.25 m)
Height: 14 ft 4¾ in (4.39 m)
Wing area: 325 ft² (30 m²)
Empty weight: 13,830lb (5,200 kg)
Loaded weight: lb (kg)
Max. takeoff weight: 28,000 lb (12,701 kg)
Powerplant: 1 × Wright J65-W-3 turbojet, 7,220 lbf (32.2 kN)
Performance
Maximum speed: 695 mph (604 knots, 1,119 km/h, Mach .91) at sea level
Range: 810 mi (704 nmi, 1,304 km) combat radius with two droptanks
Service ceiling: 46,000 ft (14,000 m)
Rate of climb: 8,200 ft/min (42 m/s)
Wing loading: 86 lb/ft² (423 kg/m²)
Armament
6× .50 in (12.7 mm) Browning M3 machine guns,
Up to 6,000lb (2,727 kg) of rockets and bombs, including one Mark 7 nuclear bomb
Avionics
A-1CM or A-4 gunsight with APG-30 or MK-18 ranging radar
Communications Equipment
AN/ARC-33 or 34 command set radio
AN/APX-6 or 6A IFF set
AN/AR-6 radio compass
AN/APW-11 or 11A radar set
AN/APN-21 TACAN set
That's all for now
, another big favourite of mine is the F105 Thud 
, one of the few early jet that look good in cam.
