CONVAIR F-102 Delta Dagger

History

The CONVAIR F-102 "Triangle Dagger" is a product of the Cold War years following the end of World War II, during which jet technology and aerodynamics advanced to a whole new level. Consequently, the development of increasingly powerful and streamlined aircraft followed, leading to one of the most exciting times in military aviation.

One of the main threats to Western European and American interests remained the Soviet long-range nuclear bombers, for which "interceptors" were developed in response. Based on a pure velocity concept, the interceptor uses a sophisticated computerized fire control system (FCS) to engage air targets at range. The F-102 served as a deterrent to such enemies during its early tenure, eventually evolving into a limited ground attack mount during the Vietnam War. The F-102 is used by only a handful of countries in the world and served for over 20 years before being officially retired.

While the F-102 shares an undeniable appearance with the upcoming F-106 "Delta Dart," the F-102 was more of a preliminary intercept design until the F-106 achieved its original program goals.

In August 1945, the U.S. Army Air Force, which had just begun its cessation of World War II operations, was excited by the idea of ??a jet aircraft and asked for a supersonic capable interceptor. Jet propulsion was still in its infancy during the war, but eventually overcame many technical hurdles - including the arrival of the first combat jet fighter - the German Messerschmitt Me 262. The U.S.

Air Force required a top speed of 700 mph and a service cap of 50,000 feet - two qualities that would offset the Soviet bomber. CONVAIR eventually turned to the work of German engineer Alexander Lippisch, who advocated the use of a "delta-wing" wing design for high-speed flight. Convair was formed in 1943 by the merger of CONsolidated Aircraft and Vultee AIRcraft (hence the name "CONVAIR").

CONVAIR was eventually acquired by General Dynamics and lost in aviation history.

CONVAIR has been working on a proprietary development of a delta wing for the US Air Force known as the "XF-92A". The concept combines an extremely swept wing leading edge with a straight trailing edge, while eliminating the horizontal stabilizer found in traditional aircraft designs. The first flight of the experimental airframe took place on April 1, 1948.

Power comes from an Allison J33-A-29 series turbojet engine producing 7,500 pounds of thrust, providing a speed of 718 mph and a service ceiling of 50,750 feet. The fuselage is nicely streamlined but rather low in shape, topped by a triangular vertical tail and a triangular main wing assembly behind the framed cockpit shell. The engine was sucked in through the open headcase.

However, pilots did not respect the genre due to its inherent propensity to fly aggressively and its sub-par nature. The U.S. Air Force ended the research project with a formal rejection.

In October 1948, the U.S. Air Force issued a series of new requirements for interceptors built around the MX-1179 Advanced Electronic Fire Control System (FCS) to manage the proposed airborne radar and missile weapons.

The aircraft needed to be capable of Mach 2 and be ready for production by 1954, hoping to fill the USAF's inventory with high-performance interceptors and Soviet bomber deterrents. The project was developed on two fronts - Hughes was selected to produce the key FCS, and CONVAIR was eventually awarded the rights to develop the airframe.

CONVAIR leveraged the knowledge gained during the development of the XF-92 and presented its new XF-102 prototype, which has a similar shape.

The XF-102 was no different from the previous XF-92, although it had a longer fuselage and larger area delta wings. As with previous designs, all wing surfaces are triangular with pointed tips and swept leading edges. A single engine is embedded in the tubular fuselage to provide the necessary thrust, while the cockpit is incorporated into the design.

Despite the intention to install the upcoming Wright J67 series turbojets (based on licence from Bristol-Siddeley Olympus in the UK), delays forced the temporary selection of the Westinghouse J40 series. When the J40 project proved to be a disaster, the Pratt & Whitney J57 series was chosen.

Development of the MX-1179 FCS was also still ongoing, initially forcing the incorporation of the less complex MG-3 FCS system. As such, XF-102 will serve as a technical stepping stone to address the project's problems, while key technical components continue to be developed on their own schedules. It is clear that the XF-102 will be the base interceptor for the F-102A production line, while the later branded F-102B will introduce the required FCS and engines as planned.

With this approach, the USAF will obtain a capable interceptor until the program objectives are fully achieved, resulting in a very streamlined end product.

As with other USAF programs, the XF-102 prototype was further developed into the "YF-102" evaluation model form. The first flight was recorded on October 24, 1953, although the prototype was lost less than two weeks later. A second airworthy prototype was completed and launched in January the following year, but proved to be flawed - it couldn't break the sound barrier and could only fly at subsonic speeds.

CONVAIR engineers then addressed issues inherent in the YF-102 design by applying a "Whitcomb Zone Rule" design method inspired by wartime Germany, which allowed the fixed-wing aircraft to reduce drag at speeds at and beyond Mach 1. The YF-102 fuselage was then extensively redesigned with the addition of an elongated fuselage (by 4 feet) that was tucked into the middle. In addition, newer, more powerful J57 turbojets (PW J57-P-23 with 16,000 lb thrust) were installed and aspirated through revised air intakes, which were themselves larger.

The wing of the YF-102 was further improved, and in this improved form became the "YF-102A".

The first flight of the YF-102A on December 20, 1954 was able to achieve the required supersonic speed and peak service, proving the success of the redesign. After the new aircraft was improved to an acceptable level, the USAF ordered the model for serial production, known as the "F-102 Delta Dagger".

The initial production brand will be "F-102A" and the 889 will eventually be manufactured by CONVAIR. The arrival of the F-102 marked the world's first operational delta-wing supersonic aircraft. Production continued until September 1958.

The F-102 exudes speed in appearance, thanks to its sharp, clean lines and single-minded purpose. The fuselage is long and skinny, with a cockpit behind the nose cone assembly. The air intakes for the single engine intake are located on either side of the cockpit wall and extend the entire length of the fuselage to these intakes and are covered by the engine exhaust rings. The delta wing configuration is set on either side of the circular fuselage, heavily swept along the leading edge and straight along the trailing edge, where the two edges meet at the outboard point. The fuselage spine is covered by a large vertical tail, which is basically a third triangular face terminated by a truncated tip.

The cockpit is a two-piece frame unit that provides adequate side, forward and top views. Rear visibility is largely blocked by the raised fuselage spine, while the bulges of the side air intakes destroy any lateral "looking down" character. However, the core design of the F-102 is as an interceptor rather than a true "fighter", so cockpit visibility is not purely a requirement of the program.

The landing gear is a traditional "trike" arrangement, consisting of two main landing gear legs under the wings and a front wheel leg under the cockpit floor - all fully retractable. The original production brand received the Hughes MG-3 series FCS, while later models featured the more advanced Hughes MG-10 series.

Power is provided by a Pratt & Whitney J57P-23 series turbojet engine rated at 11,700 pounds of thrust. The afterburner, which can achieve 17,200 pounds of thrust, essentially pumps raw fuel directly into the engine, temporarily increasing speed at the expense of reduced operating range. This gives the aircraft a top speed of 825 mph and a service ceiling of nearly 54,000 feetthough not the Mach 2-capable aircraft originally envisioned, but far exceeding the Air Force's original interception requirements.

The range is 1,350 miles and the rate of climb is close to 17,400 feet per minute. As an interceptor, the F-102 must gain altitude, fly to the intercept point at high speed, and accurately deploy the gun within range within a given time window.

Interestingly, at the time these guns were located in three internal compartments hidden under the main hull section. This helps reduce external airflow under the aircraft and squeeze as much speed as possible out of the design. To some extent, this also reduces the aircraft's inherent radar signature. As an interceptor, the F-102 was armed with air-to-air guns and was designed to take out large predatory Soviet bombers. A total of six missiles can be carried, which are primarily a mix of semi-active radar-guided (AIM-4A Falcon) and infrared-guided (AIM-4C Falcon) to cover the two most likely target intercept scenarios.

Arranged for the transport of 24 x Folding Fin Aviation Rockets (FFAR) along the two forwardmost gun bay door panels, these rockets can be used at close range against large targets with acceptable results. The pilot or fire control system can manage the weapons through additional control columns in the cockpit. FCS can automatically guide the aircraft to the target.

Later in service, the F-102 was approved to carry the AIM-26A nuclear Falcon nuclear missile, expanding its deterrent nature against the Soviet Union. Since this was the era of military aviation, a major shift from airborne cannons to missile technology, the series never had a built-in cannon.

Drop tanks - one under each wing - became commonplace to increase the F-102's range.

As the Delta Wing fighter was a relatively new addition to the USAF contingent, this led CONVAIR to develop a viable two-seat trainer derivative, designated the "TF-102A". This form retained its combat capabilities, but was greatly hindered in performance, thanks to the revised curved forward fuselage section required to seat students and instructors side by side.

A total of 111 TF-102 brands were manufactured and used extensively in the training of all F-102 operators.

The F-102 was finally delivered to the pending USAF units in April 1956, two years after the scheduled proposal date, to produce a viable operational interceptor product. New pilots were trained using the existing two-seat TF-102A retrofit model. The F-102 also served with the U.S. Air Force Air Defense Command until 1960, protecting the continental United States from Soviet air strikes.

It wasn't until America's involvement in the Vietnam War expanded that the F-102s in service with the US Air Force were used in rage, where every capable aircraft seemed to be used to prevent South Vietnam from losing communist rule. Introduced in 1962, the F-102 was originally used as an interceptor because of its speed and is now painted in standard Southeast Asian camouflage patterns. Later in its tenure, the F-102 entered service, providing combat escort for the large, bulky and vulnerable Boeing B-52 Stratofortress bomber.

As the war progressed, the demand for "strike" aircraft increased, and the F-102 and TF-102 trainers were used for ground attack, armed with high-explosive rocket launchers. The F-102s remained in theater service until 1968, when only one of them was lost in enemy air combat.

In the end, a total of 15 F-102s were lost throughout the war.

When the Pratt & Whitney J75 series turbojet came out, the F-102 airframe was heavily redesigned and modified to accept it. Other changes to its design resulted in a basically new interceptor that bypassed the intended F-102B production brand and replaced it with a Mach 2-capable "F-106 Delta Dart" built elsewhere replaced by the production line, which is described on this website. The Delta Dart first flew on December 26, 1956, and the series was officially launched in June 1959.

342 prototypes of this type were produced and were very popular among pilots.

As the years of peak usage faded, the large stables of the F-102 fuselage were converted into manned and unmanned target drones for weapons training. The first modification took place in 1973 and eventually included 217 modifications, designated "QF-102A" and later "PQM-102A/B", with the last F-102 UAV destroyed in 1986.

These help hone the skills of USAF Top Gun pilots in an active and "live" classroom environment.

There is also a lesser known "strike variant" of the F-102, which would be called the F-102C if it were ever produced. This type is for close range work using a J57-P-47 series engine and internal cannon. A pair of underwing hardpoints should be added to support conventional throwing weapons. Internal refueling probes will expand the aircraft's operating range, as will the proposed larger internal fuel storage.

Eventually, two "YF-102C" development models were developed, but never implemented.

The F-102 has limited overseas service, delivered to U.S. allies in Turkey and Greece. Turkey began taking delivery of their 50 F-102As and trainers in 1968, which were models of the US Air Force. Turkish use of the F-102 ended in 1979.

Greece adopted its 24 F-102As and trainer mounts in 1969 and used them until 1978. The United States officially abandoned the use of the F-102 interceptor in 1976. He has served with Air Defense Command, Alaska Air Force Command, U.S.

Air Forces Europe, Pacific Air Forces, and the Air National Guard. In total, the F-102 stores an inventory of more than 70 interceptor squadrons, with 26 squadrons (all staffed by Air Defense Command) available at their peak.

The advent of more powerful "multi-role" aircraft and improved ground-launched interceptor missiles eventually led to the end of the "interceptor" as an accepted part of the modern battlefield. The comparable F-106 served in the Air National Guard until 1988.