Republic F-84F Thunderstreak

In 1948, 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 Oscar 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.

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 (a unique design, the canopy was mounted on a pair of hydraulic rams and a pivoted lever arm that allowed it to lift up and backwards while remaining almost level with the fuselage, instead of the more common simple hinged canopy), 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 improved upon 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

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.

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 jet pipe was not perfectly straight (in addition to the usual thrust losses from the long jet pipe). On a hot day, 7,500 feet (2,300 m) of runway were required for takeoff roll. A typical takeoff speed was 160 knots (180 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).

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 miles (3,936 km) flight from Los Angeles to New York.

With the appearance of the Republic F-105 Thunderchief, which used wing-root mounted air intakes of a similar design to those fitted on the RF-84F, the photorecon variant Thunderflash 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 with the USAF 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 RF-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.

YF-84F

Two swept-wing prototypes of the F-84F, initially designated YF-96.

F-84F Thunderstreak

Swept wing version with Wright J65 engine. Tactical Air Command aircraft were equipped with Low-Altitude Bombing System (LABS) for delivering nuclear bombs. 2,711 built, 1,301 went to NATO under Mutual Defense Assistance Program (MDAP).

GRF-84F

25 RF-84Fs were converted to be carried, and launched from the bomb bay of a GRB-36F bomber as part of the FICON project. The aircraft were later redesignated RF-84K.

RF-84F Thunderflash

Reconnaissance version of the F-84F with intakes relocated to the wing-roots, 715 built.

RF-84K Thunderflash (FICON)

RF-84F with a retractable probe for hookup with carrier GRB-36Ds and tailplanes with marked anhedral, 25 redesignated from RF-84F.

XF-84H

Two F-84Fs were converted into experimental aircraft. Each was fitted with an Allison XT40-A-1 turboprop engine of 5,850 shaft horsepower (4,365 kW) driving a supersonic propeller. Ground crews dubbed the XF-84H the Thunderscreech due to its extreme noise output.

YF-84J

Two F-84Fs were converted into YF-84J prototypes with enlarged nose intakes and a deepened fuselages for the General Electric J73 engine; the YF-84J reached Mach 1.09 in level flight on 7 April 1954. The project was cancelled due to the excessive cost of converting existent F-84Fs.

 Belgium

• Belgian Air Force - 197 x F-84F, 34 x RF-84F operated from 1955.

 Denmark

• Royal Danish Air Force - 23× RF-84F received, in service from 1957 to 1971.

 France

• French Air Force - 328 F-84Fs and 88 RF-84Fs received from 1955.

 Germany

• West German Air Force - 450 F-84Fs and 108 RF-84Fs received. In service from 1956 to 1966.

 Greece

• Greek Air Force

 Israel

• Israeli Air Force - 18 French F-84Fs along with their pilots were temporarily transferred to the IAF during the Suez Crisis.

 Italy

• Italian Air Force - operated 194 Republic F-84F Thunderstreak and 78 RF-84F Thunderflash from 1956 until 1974

 Netherlands

• Royal Netherlands Air Force (180× F-84F, 24× RF-84F 1955-1970)

 Norway

• Royal Norwegian Air Force (35× RF-84F 1956-1970)

 Taiwan (Republic of China)

• Republic of China Air Force - About 25 RF-84Fs operated from 1954.

 Turkey

• Turkish Air Force

 United States

• United States Air Force (1496× F-84F, 388× RF-84F 1952-1972)

• On 7 July 1954, one F-84F of a flight of four en route to Bergstrom Air Force Base in Austin, TX, crashed into the Kansas City, Kansas business district shortly after departing Fairfax Municipal Airport, Kansas City, KS. 2nd Lt. John H. Kapeles, pilot, assigned to the 27th Fighter Escort Wing, died in the crash. Three civilians died on the ground when the plane crashed onto their homes. The plane had just come off the General Motors Fairfax Assembly Plant production line and had been test flown. Eyewitnesses reported that the plane plunged at a high speed toward the ground after the flight had banked toward the west from the east. The three remaining planes returned to Fairfax Municipal Airport.
• On 9 December 1955, a USAF F-84F on an instrument training flight from RAF Sculthorpe in Norfolk experienced a flameout and the pilot ejected. The aircraft crashed into Lodge Moor Hospital, Sheffield. The crash killed one patient and injured seven others.
• On 19 February 1956 1st Lt Thomas W. Sonnett a pilot for the Air National Guard and an officer in the 146th Fighter Interceptor Squadron based out of the Pittsburgh International Airport. Returning from a routine training flight Sonnett experienced a flameout at 2500 ft. Rather than bailout over populated areas, he announced to his wingman that he was going to try and "crash it". He was able to make it as far as an open farm field just a few miles from base but, seconds before reaching the ground his landing gear clipped some trees. Sonnett, age 32, did not survive the crash. He just 1 mile from his home where his wife and children had been awaiting his return. [from pg 14 of "The Tanker Times" 2023]
• On 4 April 1957, the USAF Captain Richard W. Higgins died after a low ejection near the Fürstenfeldbruck Air Base. He was flying one of the first F-84Fs of the German Air Force.
• On 1 August 1960, Captain Finn Erik Andersen of the Royal Norwegian Air Force flying F-84F Thunderflash registration T3-S crashed into the Styggmann peak of Skrimfjella in Southern Norway. The pilot was killed. As of 2023, some wreckage remains on the mountain.
• On 20 November 1960 a F-84F Thunderstreak of the Royal Netherlands Air Force crashed at 7:50pm into a farm in Lutjelollum between Wjelsryp and Franeker, the Netherlands. The pilot and the family of six people who lived at the farm were all killed. The farm was destroyed and burned down and the livestock was killed.
• On 14 September 1961, two West German F-84Fs of the West German Luftwaffe crossed into East German airspace due to a navigational error, eventually landing at Berlin Tegel Airport, evading a large number of Soviet fighter aircraft. The event came at a historically difficult time during the Cold War, one month after the construction of the Berlin Wall.
• On 28 January 1962, the USAF Lieutenant Donald Slack died after striking a 6,188 ft (1,886 m) (ASL) mountain in central France in his F-84F of the New Jersey Air National Guard. The book Stranger to the Ground by Richard Bach was dedicated to him.

Belgium

F-84F Thunderstreak

• 52-6584, FU-197, Balen-Keiheuvel Aerodrome
• 52-7169, FU-30, Royal Museum of the Armed Forces and Military History in Brussels
• 53-6677, FU-66, Kleine Brogel Air Base
• 53-6888, FU-177, Leopoldsburg/Beverlo Airfield

Denmark

RF-84F

• C-581, Flyvestation Karup Historiske Forening Museet, Karup
• C-264, Danish Collection of Vintage Aircraft, Skjern

Germany

F-84F Thunderstreak

• tactical number DC-101 - behind main gate, inside Büchel AB, Büchel.
• tactical number DD-113, at the entrance road towards Memmingen Airport

Greece

F-84F Thunderstreak

• tactical number 26595 - Hellenic Air Force Museum (Μουσείο Πολεμικής Αεροπορίας)
• tactical number 37050 - Larissa air base

RF-84F Thunderflash

• tactical number 17-011 (s/n 51-17011 - ex-Luftwaffe) - Hellenic Air Force Museum (Μουσείο Πολεμικής Αεροπορίας)

F-84F Thunderstreak

• tactical number unknown - Rentina Agrafon (Ρεντίνα Αγράφων).

Italy

F-84F

• 53-6892, Italian Air Force Museum, Vigna di Valle near Rome.
• D1003 - Museo Nazionale Scienza e Tecnologia Leonardo da Vinci, Milan

RF-84F Thunderflash

• 52-7458, Italian Air Force Museum, Vigna di Valle.

Netherlands

F-84F

• 52-7185 - P-134, in storage at ROCvA Airport College, Hoofddorp
• 53-6600 - P-254, in storage at Nationaal Militair Museum, Soesterberg
• 53-6612 - P-226, on display at Nationaal Militair Museum, Soesterberg

RF-84F

• 51-11253 - TP-19, in storage at Nationaal Militair Museum, Soesterberg

Poland

F-84F

• 52-7157 (Ex-Belgium), Polish Aviation Museum, Kraków

Turkey

F-84F

• 52-8733, Istanbul Aviation Museum

RF-84F

• 51-1860 - Bursa Uludag University
• 51-1901, Istanbul Aviation Museum
• 51-1917, Istanbul Aviation Museum

United Kingdom

F-84F

• 52-6541, North East Land, Sea and Air Museums, Sunderland
• 52-7133 - Bentwaters Cold War Museum

United States

XF-84F

• 49-2430, National Museum of the United States Air Force, Dayton, Ohio

F-84F

• 51-1386, Barksdale Global Power Museum, Barksdale AFB, Louisiana
• 51-1620, Empire State Aerosciences Museum in Glenville, New York
• 51-1640, Hill Aerospace Museum, Hill AFB, Utah
• 51-1659, Combat Air Museum, Topeka Regional Airport at Forbes Field, Topeka, Kansas
• 51-1714, Strategic Air Command & Aerospace Museum in Ashland, Nebraska
• 51-1739, Korean War memorial South Whitley, Indiana
• 51-1772, Aerospace Museum of California in McClellan, California
• 51-1786, Virginia Air & Space Center in Hampton, Virginia
• 51-9350, Air Force Flight Test Center Museum at Edwards AFB, California
• 51-9396, Holloman AFB, New Mexico.
• 51-9432, March Field Air Museum in Riverside, California
• 51-9433, Castle Air Museum in Atwater, California
• 51-9495, Air Force Armament Museum, Eglin AFB, Florida
• 51-9501, Yankee Air Museum, Belleville, Michigan
• 51-9531, Palm Springs Air Museum, Palm Springs, California, formerly at Octave Chanute Aerospace Museum in Rantoul, Illinois
• 52-6385, VFW Post 2503, Omaha, Nebraska.
• 52-6455, American Legion post #490, Houston, Texas
• 52-6526, National Museum of the United States Air Force in Dayton, Ohio
• 52-6553, Window on the Plains Museum in Dumas, Texas
• 52-6555, Wings of Freedom Aviation Museum in Horsham, Pennsylvania
• 52-6563, Pima Air & Space Museum in Tucson, Arizona
• 52-6701, Museum of Aviation, Robins AFB, Georgia
• 52-6993, Wilbur Wright Birthplace and Museum near Millville, Indiana.
• 52-8886, South Dakota Air and Space Museum at Ellsworth AFB, South Dakota
• 52-9089, Kansas Aviation Museum, Wichita, Kansas

RF-84F Thunderflash

• 51-1944, Pima Air & Space Museum in Tucson, Arizona
• 51-1948, Harlan Airport (HNR) in Harlan, Iowa.
• 52-7259, National Museum of the United States Air Force in Dayton, Ohio
• 52-7265, Planes of Fame Museum in Chino, California
• 52-7421, Yankee Air Museum, Belleville, Michigan

Data from Fighters of the United States Air Force, Combat Aircraft since 1945

General characteristics

• Crew: 1
• Length: 43 ft 4.75 in (13.23 m)
• Wingspan: 33 ft 7.25 in (10.25 m)
• Height: 14 ft 4.75 in (4.39 m)
• Wing area: 325 sq ft (30 m²)
• Empty weight: 13,830 lb (6,200 kg)
• Max takeoff weight: 28,000 lb (12,701 kg)
• Powerplant: 1 × Wright J65-W-3 turbojet, 7,220 lbf (32.1 kN) thrust

Performance

• Maximum speed: 695 mph (1,119 km/h, 604 kn) at sea level
• Range: 810 mi (1,304 km, 704 nmi) 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/sq ft (423 kg/m²)

Armament

• 6× .50 in (1,300 mm) Browning M3 machine guns, four mounted in nose over intake, two mounted in the wing roots, 1,800 rounds total
• Up to 6,000 pounds (2,700 kg) of rockets and bombs, including one Mark 7 nuclear bomb

Avionics

• A-1CM or A-4 gunsight with AN/APG-30 or MK-18 fire-control radar
• AN/ARC-33 or AN/ARC-34, UHF command radio transceiver
• AN/APN-21, TACAN set
• AN/APW-11/11A, Radar transponder
• AN/APX-6/6A, IFF Mark X (SIF) transponder
• AN/ARN-6, Radio compass

Richard Bach, who later wrote the bestseller Jonathan Livingston Seagull, was an ANG F-84F pilot who was once activated for duty in Europe. His first book, Stranger to the Ground, described in detail what it was like to fly the Thunderstreak in the course of an operational flight at night from England to France in adverse weather.

F-84Fs were also used to represent North Korean MiG-15 fighters in the 1958 film version of James Salters' novel "The Hunters", because none of the Soviet fighters were available during the ongoing Cold War for filming. They were painted a flat gray with red star insignia.