The (F-84) Thunderjet thread

[LuftManu]

 

Hello friends!

 

It seems that in the future we will embark on a new era of aviation, where jets co-exists with famous and powerful props.

When we talk about the Korean War, everyone knows the MiG-15, the Sabre... even the venerable F-51 returning to service as a veteran.

But what about the others?

 

In the skies over the peninsula, there were several aircraft that also played very important roles. In this case, the F-84 was an incredible platform that took on ground-clearing missions, starting out as an escort fighter. Does that ring a bell for Thunderbolt enthusiasts?

Looks like we will be getting one in Korea, an it's the G variant.

 

In this thread, we’re going to talk a bit about it and its different variants.

 

Welcome to the Thunderjet lounge!

 

 

 

The birth of the Thunderjet

 

In 1944, Republic Aviation, under the direction of chief designer Alexander Kartveli, started developing a turbojet-powered replacement for the P-47 Thunderbolt, a piston-engined fighter.

 

Early efforts to adapt the P-47 for jet propulsion were unsuccessful due to its bulky fuselage. As a result, Kartveli and his team designed a completely new aircraft, the F-84 Thunderjet, with a slimmer fuselage housing an axial compressor turbojet engine and nose air intake. The USAAF set demanding performance requirements for the new day fighter, aiming for a top speed of 600 mph and a combat radius of 850 miles, along with heavy armament. However, these specifications were later reduced to more achievable goals due to the limitations of early jet engines.

 

In November 1944, Republic received an order for three prototypes, designated XP-84, and the aircraft was named "Thunderjet" to continue the legacy of the P-47 Thunderbolt. Wind tunnel testing revealed stability issues, and weight concerns due to the low thrust of early turbojets led to further design modifications. The first prototype was rolled out in December 1945, but engine availability delayed its first flight until February 1946. Despite initial challenges, the second XP-84 prototype set a national airspeed record in September 1946.

 

As the design evolved, Republic produced 15 service test YP-84As, which featured improved engines and the ability to carry wingtip fuel tanks. However, the impact of these tanks on the aircraft's structure was not fully understood, leading to problems later in the development process. By the time production of the P-84B variant began in 1947, the Thunderjet had undergone limited flight testing, which contributed to structural issues that surfaced during operational use.

 

With the establishment of the U.S. Air Force in 1947, the aircraft's designation was changed from P-84 (Pursuit) to F-84 (Fighter). Despite the challenges faced during its development, the F-84 Thunderjet became a significant aircraft in the early jet era, laying the groundwork for future advancements in jet-powered fighter design.

 

 

The Thunderjet Family

F-84G Cockpit

 

The Republic F-84 Thunderjet, particularly the early F-84B and F-84C models, experienced significant challenges after entering service. The F-84B became operational with the 14th Fighter Group in December 1947 but was immediately plagued by structural issues. Restrictions were imposed on its maximum speed and acceleration due to concerns about control reversal and fuselage skin wrinkling. Additionally, parts shortages and maintenance difficulties led to the aircraft being dubbed a "Mechanic's Nightmare." These issues culminated in the grounding of the entire F-84B fleet in May 1948 due to wing structural failures.

 

The F-84C, which introduced a slightly more reliable engine and modified systems, faced similar problems and was nearly identical to the F-84B. By 1948, a review of the F-84 program revealed that neither the F-84B nor the F-84C could be considered fully operational or capable of fulfilling their intended roles. The program narrowly avoided cancellation thanks to the upcoming F-84D model, which addressed many of the major faults found in earlier versions. The F-84D featured thicker wing skin, an improved fuel system, and a more powerful engine. It also had small triangular fins added to the wingtip fuel tanks to prevent structural failures caused by high-g maneuvers. The F-84D was gradually phased out by the Air National Guard (ANG) by 1957.

 

The first truly effective and combat-capable version of the Thunderjet was the F-84E, which entered service in 1950. This model included further wing reinforcement, a longer fuselage to accommodate a larger cockpit and avionics bay, improved radar and gunsight systems, and the ability to carry additional fuel tanks under the wings. These changes extended the aircraft’s combat radius significantly. Another innovation was the use of folding rocket racks that reduced drag after firing, a feature later adopted by other U.S. jet fighter-bombers. Despite these improvements, the F-84E struggled with poor operational availability, primarily due to engine shortages. The Allison engines required frequent overhauls, and the high operational tempo during the Korean War and NATO deployments exceeded the supply of replacement engines. The F-84E was eventually withdrawn from USAF service in 1956 but continued to serve with the Air Force Reserve until 1957 and with ANG units until 1959.

 

The final straight-wing variant of the Thunderjet, the F-84G, was introduced as a stop-gap measure while the more advanced swept-wing F-84F was being developed. That means that the USAF was already working into a "more advanced F-84" following the Sabre and other contemporary jets. The F-84G incorporated several significant upgrades, including a refueling boom receptacle for aerial refueling, an autopilot, an Instrument Landing System (ILS), and a more powerful J35-A-29 engine. It also had the capability to carry a Mark 7 nuclear bomb, making it one of the first jet fighters with nuclear strike capability.

 

The F-84G's canopy design was changed to a framed version, which was also retrofitted to earlier models. Production of the F-84G continued until July 1953, with over 3,000 units built. Of these, 789 went to the USAF, and the remainder were delivered to U.S. allies under military aid programs. The F-84G remained in service with the USAF until mid-1960 and played a critical role in building up NATO air forces during the early Cold War.

 

 

In summary, the F-84 Thunderjet's early models faced numerous technical difficulties and operational setbacks, but the program persisted and gradually improved with each new variant. The F-84D, E, and G models overcame many of the initial issues, leading to a more reliable and capable fighter-bomber that served both the U.S. Air Force and its NATO allies throughout the 1950s. Despite its challenges, the F-84 contributed significantly to the development of jet fighter technology and the strengthening of Western air power during the early Cold War period.

 

 

 

In the Korean Theater of Operations

 

 

The Republic F-84 Thunderjet played a significant role during the Korean War, demonstrating its capabilities despite facing several challenges. Following the entry of the People's Republic of China into the conflict in October 1950, the U.S. Fifth Air Force requested additional support, leading to the deployment of the F-84.

 

Initially, the earlier F-84B and F-84C models could not be deployed overseas due to their limited engine life of only 40 hours. Instead, the more advanced F-84D and F-84E models were considered suitable for combat. The 27th Fighter Escort Group, equipped with F-84Es, was transported to the Far East aboard the aircraft carrier Bataan, arriving in Japan on November 30, 1950. After maintenance, the F-84Es were stationed at Taegu airfield (K-2) in South Korea, beginning their operational missions on December 7, 1950. 

 

The Thunderjets initially focused on escorting B-29 Superfortress bombers. The first air-to-air victory by an F-84 was recorded on January 21, 1951, although it came at the cost of two Thunderjets. The F-84 struggled against the superior Mikoyan-Gurevich MiG-15, which was faster and more maneuverable. Consequently, the air-to-air combat role was shifted to the F-86 Sabre, while the F-84 transitioned to ground attack missions where it proved highly effective.

 

During the Korean War, the number of F-84 units in operation increased as Air National Guard groups were deployed and F-80 squadrons were converted. The Thunderjets flew a total of 86,408 missions, dropping 55,586 tons of bombs, 6,129 tons of napalm, and firing 22,154 rockets. The USAF credited the F-84 with destroying 60% of all ground targets during the conflict. Notable missions included the 1952 attack on the Sui-ho Dam. The F-84 also became the first USAF fighter to use aerial refueling, which was a significant operational milestone.

 

In terms of aerial combat, F-84 pilots achieved eight kills of MiG-15s, though Soviet claims suggested the loss of 64 Thunderjets. The total losses for the F-84 during the Korean War amounted to 335 aircraft, with 249 lost in combat and 56 in non-combat situations. According to the USAF FY1953 statistical digest, 305 F-84s were lost overall, highlighting the intense and challenging nature of the conflict.

Overall, the F-84 Thunderjet made substantial contributions to the Korean War effort, particularly in ground attack roles, and was a pioneering aircraft in terms of aerial refueling and operational effectiveness in a challenging combat environment.

 

More about combat operations and ground attack in future updates!

[LuftManu]

Reserved!

[=BLW=Pablo]

I say yes to your suggestion, but I would include the F-84F as well.

 

[Trooper117]

The F-84F never saw action, it didn't become operational until November 1954...

[Skycat1969]

F-84F Thunderstreak was supposed to be an easy conversion to a swept-wing design. It didn't work out that way and there was a delay delivering Thunderjets to Strategic Air Command's initial F-84F squadrons. Additional straight-wing Thunderjets were ordered in the interim, which is why there is the F-84G series.

[Avimimus]

Thought this belongs here as well (especially as the official thread for this video will eventually be locked):