Raytheon has revealed plans to challenge Boeing and Lockheed Martin for a US Navy contract to modify a torpedo for high-altitude launch by a P-8 Poseidon.

The Raytheon Fish Hawk programme integrates a wingkit, flight-control surfaces and a guidance system to a Mk 54 or Mk 46 torpedo, says Mark "Smoke" Borup, senior business development manager for Raytheon's advanced missiles and unmanned aircraft systems unit.

The objective of the USN's High Altitude Anti-Submarine Warfare Concept (HAAWC) programme is to allow the P-8 to launch at high altitude. The stand-off distance protects the P-8 from an emerging new class of submarine-launched, anti-aircraft missiles. The concept also would reduce the stress caused by diving to low altitude on the P-8 airframe.

Raytheon's approach with the Fish Hawk is unique among its competitors in a key area, Borup says. Instead of modifying an existing wing-kit for the Fish Hawk, Raytheon developed an all-new design over the last three years, he says. The purpose-built design allows the Fish Hawk to be loaded on each of the P-8's internal and external weapons stations.

The Raytheon design also includes a unique pivot-wing, with a spring-loaded mechanism releasing the wing into position after the torpedo is launched. The Fish Hawk is designed to be launched upside-down and right itself after the wing deploys. A tail guidance section, which includes four fins, is also deployed at the same time as the wing.

Raytheon has performed a single flight test in March 2008 to demonstrate that the technology works, Borup says. Raytheon had planned to perform two flight tests, but the single event achieved all of the desired test results, he adds.

The Fish Hawk uses a global positioning/inertial navigation system to glide to a location in the proximity of the targeted submarine. As the weapon reaches a specific point in space, the wingkit and guidance section is jettisoned. The torpedo drops into the water, using its terminal guidance system to fix the position of the target.

Raytheon has not integrated a datalink on Fish Hawk. However, Borup says, the company is aware that the USN eventually plans to adopt a datalink for such weapons, and has made provisions for the Fish Hawk to accept a datalink.

Source: Flight International