
The Vickers Type 125 Vireo was designed against Specification 17/25, which sought a low power, single-seat shipboard fighter aircraft. The Vickers design featured all-metal construction with an underlying primary structure covered by thin, externally stiffened, skins to wing and fuselage.
Power was provided by a single 235 hp Armstrong Siddeley Lynx IV engine. The Vireo was a low wing monoplane which carried two machine guns in the wings, firing outside the propeller disc. The sole prototype (N211) was first flown in early March 1928, a delay being incurred due to extensive structural investigations carried out at the Royal Aircraft Establishment (RAE) during the construction of the prototype.
Early flying indicated a lower than expected performance, attributed to a much reduced engine output than that expected.
In the interim, the Vireo was delivered to Martlesham Heath for official trials (in a landplane configuration) as the planned tests in a seaplane configuration were deferred, awaiting the delivery of a replacement engine.

During the tests at Martlesham, the aircraft suffered a number of niggling failures and a tendency to drop suddenly just before landing. Despite this deficiency, the aircraft was overhauled and flown to Gosport on 12th July for the purpose of deck landing trials on HMS Furious.
The planned seaplane trials did not take place and the concept of a low-powered fighter was deemed unsuccessful, due to its flight performance offering no advantage over the contemporary Fairey IIIF.
Variants & Numbers
- One only, serial number N211.
Specification
Powerplant
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One 235 hp Armstrong Siddeley Lynx IV engine
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Span
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35 ft 0 in
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Maximum Weight
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2,550 lb
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Capacity & Armament
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Pilot; two Vickers machine guns in the wings, firing outside the propeller arc.
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Maximum Speed
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120 mph
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