Avro Canada CF-105

Avro Canada CF-105 Arrow
Replica of the CF-105 "Arrow"
Type:	Interceptor
Design country:	Canada
Manufacturer:	Avro Canada
First flight:	March 25, 1958
Commissioning:	Never put into service
Production time:	Was never mass-produced
Number of pieces:	5

The Avro Canada CF-105 Arrow was a delta wing - interceptor of the Canadian manufacturer Avro Aircraft (Canada) . The starting point was a 1953 design study. The CF-105 was capable of Mach  2 speeds at 50,000 feet (15,000 meters) .

The test program began in 1958, but was canceled in 1959, as was the development of the planned Orenda Iroquois engine. The debate about this demolition continues to this day.

prehistory

After World War II , the Soviet Union began developing long-range bombers capable of carrying nuclear weapons to Europe and North America. As a result, some Western countries designed interceptors to destroy these bombers before reaching their targets.

AV Roe Canada Limited , a subsidiary of Hawker Siddeley founded in 1945 , began designing a jet-powered fighter aircraft for the Canadian Air Force in 1946. The result was the Avro CF-100 "Canuck" all-weather fighter , which was put into service in 1953.

Due to the long development time for new fighter jets and the threat posed by jet-powered bombers of the Soviet Union, the search for a successor to the CF-100 began at an early stage. In March 1952, Avro Canada received the requirements profile for a supersonic, missile-armed, all-weather interceptor.

Design and development

German research during the Second World War had found some possible solutions for supersonic flight. In this way, the problem of the resulting shock waves could be solved by using very thin wings. However, these could not accommodate fuel tanks or weapon positions.

An alternative was the sweeping of the wings, as was already intended for the Canuck CF-103 further development. However, the development costs of the CF-103 would have been far higher than the increase in performance compared to its predecessor.

Instead, the designers opted for a delta wing , which had a larger area and more interior space than the swept wing. This made it possible to increase the flight altitude and - thanks to enlarged tanks - the range. In return, disadvantages at low speeds and altitudes were accepted, which played only a minor role in an interceptor.

Two versions of the C104 were up for discussion  - the single-jet C104 / 1 and the twin-jet C104 / 2 . Both aircraft were designed as low- wing planes and had newly developed Orenda TR.9 engines. The armament was Velvet Glove guided missiles developed by Canadair , for which internal weapon positions were available. The pilot should be assisted by a fully automatic weapon control system similar to that of the F-86D Saber .

The discussions between Avro and the Canadian Air Force led to a large number of possible designs with which the requirements from the Specification AIR 7-3 program of April 1953 could be met.

In particular, AIR 7-3 required:

• two pilots dispensing with a fully automatic weapon control system
• two engines to increase the total weight and thus the amount of fuel
• a range of 300 nautical miles (556 km) for normal flights
• a range of 200 nautical miles (370 km) for high-speed interception missions
• Use of 6,000 feet (1,830 m) long runways
• a speed of Mach 1.5 at 50,000 feet (15,000 m) altitude
• Changes in direction under 2 g load without loss of speed at Mach 1.5 and 50.0000 feet.
• The time between the start command and reaching the 50,000 feet operating altitude at Mach 1.5 should be less than five minutes
• The time between landing and restarting should be less than ten minutes

An investigation found that no US , French or UK aircraft could meet these requirements.

Avro presented its revised C105 in May 1953, basically a C104 / 2 with a two-man cockpit and Martin Baker Mk.5 ejection seats. The change to the shoulder- wing design led to improved accessibility to the weapons and engines. By placing the uniform wing on the fuselage, the construction could be simplified and the stability increased. The design required a very high, three-legged chassis with double tires, which had to be accommodated in the thin delta wing with a sawtooth leading edge that was swept at 60 °. After numerous tests, the wing area was set at 111 m² and contained six integral tanks (two more in the fuselage). On the side of the box-shaped fuselage were the rectangular air inlets and the engines. There were three drives to choose from. In the end, the Rolls-Royce RB.106 engine prevailed against the Bristol B.0L.4 Olympus and Curtiss-Wright J67 models . A braking parachute was attached under the large vertical stabilizer in a conical casing above the air outlet openings of the engines.

The gun bay was larger than that of the C104 / 2. The intended Hughes MX-1179 weapon system allowed the use of radar and infrared guided missiles, such as four to six Falcon. The development of the radar-controlled Velvet Glove missile was discontinued in 1956 due to unsolvable problems.

In July 1953 Avro was commissioned to build a design study, for which an initial $ 27 million was made available. In response to the new Soviet Myasishev M-4 bomber and the hydrogen bomb tests , an additional $ 260 million was released for five Arrow Mark 1 test aircraft and 35 Arrow Mark 2 series aircraft.

production

Avro Canada CF-105 "Arrow" (replica in the Toronto Aerospace Museum )

To save development time, classic prototypes were not built and the results of the test flights were implemented directly in series production. In order to keep the risk to a minimum, a very extensive test program was decided. In fact, very few changes had to be made, especially to the wings.

A magnesium - titanium alloy was used for the hull , an expensive material that was rarely used at the time. The construction was otherwise conventional, although the avionics with autopilot and automatic landing system were designed quite modern.

In 1954 the RB.106 program was canceled, instead the designers provided the J67 engine. Since this was no longer available since 1955, the P&W J75 drive had to be used for the first test flights . At the same time, Orenda began developing the Orenda "Iroquois" PS-13 with 125 kN afterburner thrust, which was to be built into the Mark 2 version. In the end, only the previously rejected Bristol-Olympus engine went into production.

In 1956 the decision was made to do without the MX-1179 system and the Falcon missiles. Instead, the Canadian Air Force requested the more advanced, but still untested fire control system RCA-Victor Astra and the also untested AIM-7 Sparrow .

Production of the Mark 1 began in 1955, the rollout of the first prototype RL201 (25201) took place on October 7, 1957. Since there were problems with the landing gear, the machine had to be modified and so the first flight did not take place until March 25, 1958 with Jan Zurakowski on board. The J75 engine served as the drive; a fire control system was not yet available. On the third test flight, the aircraft broke the sound barrier for the first time. When landing after the eleventh flight, the landing gear broke and the machine touched down on its stomach. But she flew again on October 5, 1958. The second prototype took off for the first time on August 1, 1958 and later reached the highest speed at Mach 1.96. A total of five copies were built and completed test flights by February 1959. The sixth prototype RL206, the first Mark 2, already had Iroquois engines. Further variants were in preparation, but were no longer built.

Abort the program

In June 1957 there was a change of government in Canada and thus a rethinking of the Arrows program. Now the threat posed by nuclear missiles was rated higher than that of enemy bombers. The money available was therefore to be spent on a missile defense system; there were no longer enough funds available for the CF-105. In addition, the Canadian Air Force was not enthusiastic about the machine due to its enormous size and its limited versatility. The Astra / Sparrow program was terminated as early as September 1958, and on February 20, 1959 it was finally terminated shortly before the sixth prototype was completed.

Around the same time, similar programs were discontinued, for example in the United States with the Republic XF-103 and the North American XF-108 . A similar decision concerned the UK's aircraft projects.

The Canadian government's decision resulted in the immediate layoff of 14,000 workers at Avro and Orenda. Around 30,000 jobs were lost, including suppliers.

For fear of espionage, almost all aircraft, components and production documents were destroyed within two months. This quick action encouraged the emergence of some conspiracy theories .

The bow section of the first Arrow Mark 2 (RL206) was the only one that remained and can be viewed in the Canada Aviation and Space Museum in Ottawa. A replica of the machine is also in the Canada Aviation and Space Museum .

Two true-to-scale test models of three meters in length from the development period were discovered in Lake Ontario in 2017 and are to be recovered.

Technical specifications

Parameter	Data
crew	2
length	23.71 m
span	15.24 m
height	6.25 m
Wing area	113.8 m²
Empty mass	22,245 kg
Takeoff mass	31,120 kg
Cruising speed	977 km / h
Top speed	2,104 km / h
Rate of climb	226 m / s
Service ceiling	18,290 m
Range	2,400 km
Radius of action	480-660 km
Engines	2 × Pratt & Whitney J75 -P-3 or P-5 with 104.6 kN thrust
Avionics	Hughes MX-1179 fire control system

Intended armament

• Guided missile: 8 × AIM-4 Falcon , Canadair Velvet Glove (until 1956), 2 AIM-7 Sparrow II 2D
• unguided missiles: 1–4 × AIR-2 Genie

Comparable types

• Convair F-106 Delta Dart
• English Electric Lightning
• McDonnell F-101B Voodoo
• North American XF-108 Rapier
• Saab 35 Draken
• MiG-25

See also

• List of aircraft types

Web links

Commons : Avro Canada CF-105  - Collection of images, videos and audio files

• Arrow Archive (English)

Individual evidence

1. ↑ FliegerRevue April 2009, pp. 83–85, The Broken Arrow - CF105
2. ↑ Avro Canada CF-105 Arrow 2. In: Collections. Canada Aviation and Space Museum, accessed December 9, 2014 . 
3. ↑ The secret flyer Arrow at the bottom of Lake Ontario . In: spiegel.de . December 3, 2017, accessed December 3, 2017.