SNECMA Atar

Atar 08 and 09

With the Atar 101 now sitting at the low end of the power scale, in 1954 SNECMA started the design of a more radical upgrade, the Atar 08.

Overall design and dimensions were similar to the 101, but the new engine included a nine-stage compressor in place of the earlier seven-stage one, and a smaller two-stage turbine to power it.

There were many detail improvements as well, including the replacement of the original compressor rotor with a new one made of magnesium alloy.

The first Atar 08 B-3 produced 9,500 lbf (42,000 N) and had a slightly improved overall pressure ratio of 5.5:1.

A new and much improved afterburner was designed for the engine, resulting in the Atar 09.

It was first tested in January 1957 at 12,350 lbf (54,900 N), and was soon improved to 13,230 lbf (58,800 N).

A further improved afterburner with eighteen flaps in place of the two-flap system of the earlier designs was introduced on the 09C model in December 1959.

This version also featured a new starter from [Vous devez être inscrit et connecté pour voir ce lien] that provided compressed air directly into the engine allowing it to start without the compressor running at full speed.

The Atar 9D replaced the exhaust and afterburner area with one made of [Vous devez être inscrit et connecté pour voir ce lien] that allowed continual operation at Mach 2, up from the C's 1.4.

Air cooling was re-introduced for the Atar 9K models, further improving overall performance, and especially fuel economy.

With the Atar 8 and 9 series, the long ten years of development had finally resulted in a successful commercial design.

Thousands were produced for a variety of aircraft, including the Étendard and Super Étendard strike aircraft, Mirage III, Mirage 5 and Mirage F1 fighters, the Mirage IV bomber, and a variety of test aircraft.

Atar 9

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Super Atar

In 1955 the French government started a project to explore flight speeds up to Mach 3.0.

SNECMA began studies on an engine to power it, initially consisting of the compressor design of the existing Atar 101,
but replacing all of the light alloys with steels in order to handle the increased [Vous devez être inscrit et connecté pour voir ce lien].

This also demanded the use of an air-cooled turbine, similar to the ones from the earliest prototypes.

Such an engine, the M.26, ran in May 1957, giving 47,00 kN (10,364 lbf) without an afterburner.

Further improvements led to the M.28, which ran in September 1958 at 52,00 kN (11,466 lbf).

This work led to the Super Atar design of 85,00 kN with afterburning.

This version also included [Vous devez être inscrit et connecté pour voir ce lien], which were in the process of being widely introduced in the industry.

However, the project to build the test aircraft, the Griffon III, never went ahead and SNECMA ended development of the Super Atar in 1960.


Other developments

The Atar design was also used for a variety of larger, smaller, and experimental developments.

Of particular note are the R.104 Vulcain, a scaled-up Atar, and the much smaller R.105 Vesta.

Both engines were developed in parallel to the Atar in the early 1950s in order to fill particular performance niches, the Vulcain for the Mystère IV D, and the Vesta for a variety of designs.

None of these entered production, however; the Mystère IV D was cancelled, and the Vesta lost out to the [Vous devez être inscrit et connecté pour voir ce lien], which was also abandoned.

Description

The original Atar 101 featured a seven-stage [Vous devez être inscrit et connecté pour voir ce lien] using aluminum alloy blades attached to an aluminum rotor.

The front bearing was held in place by four vanes, with the "left" one as seen from the front containing a power takeoff shaft.

One unique feature of the Atar designs was the separate Atar 5000 accessories section, which could be mounted in front of the engine, driven by an extension shaft.

The combustion area consisted of twenty steel flame cans arranged in a "canular" layout, exiting into the single-stage turbine.

Early models were 2.85 m long, 0.9 m in diameter, and weighed 850 kg, while The C models and on were 3.68 m lone including the long extension, 0.89 m in diameter, and weighed 940 kg.

Later versions were generally similar to the C model, although the inclusion of the afterburner increased lengths to 5.23 m, and weights varied from 925 to 1,240 kg depending on the model.

The Atar 8 and 9 used a 9-stage compressor similar to the 101, but including a steel first stage in order to improve damage resistance.

The turbine included two stages.

Length and width remained the same as the 101 models, deliberately, but weights further increased up to 1,350 kg
for the 9B.

9C

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9C

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9C

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9 K50

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9K50

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Variants


Atar 101

Used in [Vous devez être inscrit et connecté pour voir ce lien] fighter-bomber

Atar 08

Two-stage turbine and improved compressor, non-afterburning, developed in 1954-1956.
Atar 08B

Used in [Vous devez être inscrit et connecté pour voir ce lien]

Atar 08K-50

Simplified non-afterburning version of Atar 9K-50 for [Vous devez être inscrit et connecté pour voir ce lien]

Atar 09

Integrated starter, improved compressor optimized for [Vous devez être inscrit et connecté pour voir ce lien] flight, afterburner.

Atar 09C

Used in [Vous devez être inscrit et connecté pour voir ce lien] fighters

Atar 09K-10

Improved combustion chamber, turbine blade cooling; used in [Vous devez être inscrit et connecté pour voir ce lien] bombers

Atar 09K-50

improved Atar 9C with a redesigned turbine and upgraded compressor resulting in improved fuel consumption and thrust; used in [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien].

Atar Plus

Joint development with ITP and Denel, new compressor, new turbine, new electronics.

8 K50

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9 K

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9 K50

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