With their rotors close to sensitive structures, particularly on the small deck of vessels such as patrol boats, these UAVs were regarded as posing an acute danger.
Rotary-wing UAVs are maturing rapidly, with the growing demand for unmanned craft to support naval vessels operating in the littorals, as well as on the open sea. Several versions of Vertical Take-Off and Landing (VTOL) UAVs are now designed to operate from frigates and corvettes as well as submarines. One of the competitions for a shipboard UAV currently heating up in Europe is the UK Ministry of Defence plan to launch the maritime VTOL UAV. Among the contenders are Northrop Grumman offering the MQ-8B Fire Scout, EADS offering systems based on the ORCA or SHARC and Thales UK, teamed with the Austrian company Schiebel offering the S-100 Camcopter
Similar programs are expected to follow in Germany and France and later in Spain and Italy. SHARC, a fully autonomous demonstrator VSTOL UAV developed by EADS Defense & Security (DS) made its first flight prior to the 2007 Paris Airshow. In this flight the 200 kg unmanned rotary wing vehicle tested the coaxial dual-rotor propulsion and overall stability, demonstrating some of its impressive flight characteristics. The SHARC is designed for autonomous operations from shipdeck, offering highly stable flight characteristics and large payload capacity. Its dual rotor configuration provides 30 per cent more lift compared with conventional main rotor and tail boom designs. Its egg shaped oval fuselage is 2.50 metres long, 0.70 m wide and 1.2 metres high. Its maximum takeoff weight is 190 kg, carrying 60 kg of mission equipment. The helicopter is equipped with redundant flight control unit, a laser altimeter, mission control system and datalinks. The counter-rotating rotors are designed to operate with electrical actuators, thus eliminating all hydraulic components onboard. One advanced capability in SHARC's flight control system is attitude stability, improving the helicopter's ship roll compensation correction, a prerequisite for autonomous deck landing. Typical payloads considered for SHARC include maritime search radar, SAR, and electro-optical payloads. The vehicle's skin can be used in part to accommodate flat panel antennae for communications and radar.