Israel Aerospace Industries has asked the nation's defence ministry to extend the deadline in its contest for a brigade-level unmanned air system, to give it more time to test an all-new tiltrotor design.

The company has meanwhile provided first details of its developmental K-80 design, which it says offers a totally new line of systems for use by infantry units. It hopes to gain approval to pitch the tiltrotor for the Israel Defence Force's brigade-level requirement, responses for which were due by 20 September.

IAI has already performed a series of test flights with the design, which has a maximum take-off weight of 60kg (132lb), a 6h endurance and can carry a day and night (cooled) imaging payload.

The K-80 takes off vertically by using three tiltrotors powered by electric motors: two positioned on the wings and one on the aft part of the fuselage. This will enable infantry soldiers to launch the UAV, even in places that cannot accommodate a catapult. Take-off and landing will be fully automatic, with the flight profile to be either autonomous or controlled by a handheld unit.

Sources suggest that some early flight tests revealed excessive drag, plus a problem with the capacity of the aircraft's batteries. For some of the flights the aft motor was used to drive a helicopter-type rotor, but the operational configuration will have three tiltrotors.

IAI says test flights are continuing on schedule, and that the K-80 will be flown with different payloads in early 2011. The system has been developed by a team from its Malat division, with help provided by personnel from other parts of the company.

A senior IAI source desrcibes the new design as "unique and revolutionary", and says it will answer the operational needs of the nation's armed forces and foreign clients.

Elbit Systems has already offered a version of its Skylark 2 for Israel's brigade-level UAV requirement, but other potential competitors have not proposed systems. This lack of competition "complicates the situation", according to a defence ministry source.

If the selection process is not delayed to allow IAI to offer its K-80, the ministry may be forced to reissue the tender with different specifications.

Source: Flight International