A heavy carrier-based two-seat fighter armed with a turret-mounted B-25 Roc was developed in accordance with the O.30 / 35 specification. The new aircraft was developed on the basis of the "B-24 Skua" by installing a standard four-gun turret "Boulton Paul" on it.

The prototype, also known as the first production aircraft (L3057), took to the air for the first time on December 23, 1938. The second and third examples (L3058 and L3059) were prototypes of a hydro-fighter (specification 20/37) with floats. However, the test program showed the futility of further work on this option, and all the vehicles were again equipped with a wheeled chassis.

A total of 136 aircraft were produced.

Combat use. The 803rd Squadron became the first combat unit to receive the Rock in April 1939. A month later, the 800th began to receive planes. The standard number of squadrons for the summer of 1939 was determined at 6 Skua and 3 Roca. However, despite the fact that the factories regularly produced serial vehicles, by the beginning of autumn, only two combat squadrons were armed with new vehicles.

One of the Rock seaplanes was tested as a target towing machine with a winch installed in place of the turret, and was able to lift a target on a cable 1830 m long to an altitude of 3050 m, after which several land aircraft were used as target towing vehicles. By mid-1943, all aircraft were decommissioned, the last two were decommissioned in August 1943.

Photo	Description
	Drawing B-25 Roc
	Pair of B-25 Roc in flight

Bibliography

• "Encyclopedia of military engineering" /Aerospace Publising/
• "British warplanes of World War II" /under cor. Daniel March/