Israel Aircraft Industries (IAI) is to conduct later this month the first test flight of a Heron unmanned air vehicle powered by a diesel engine. Ground trials of the 180hp (135kW) powerplant have already been completed by the company's Malat division, which will next conduct a series of flight tests at varying altitudes to evaluate its suitability for sustained operations.

The Heron's current 100hp Rotax gasoline engine is capable of delivering a mission endurance of around 51h, but the company says the adapted commercial diesel design will provide several benefits for operators, including improved fuel efficiency and increased operating altitude. Diesel UAVs will also be able to use the same fuel as ground vehicles and be safer to refuel, it says.

IAI plans to equip all its future UAVs with diesel powerplants and says existing and potential customers have indicated a clear preference for heavy-fuel engines.

The increased weight of diesel engines has until now prevented their use by UAVs, but this issue is becoming less acute, it says. The company's heavy-fuel work is expected to support its proposed delivery of a new variant of the Heron for the US Army's extended-range multipurpose UAV programme.

Dubbed the Strike Heron, or Hunter II, this is being promoted by IAI in conjunction with Northrop Grumman and Aurora Flight Sciences as a replacement for the army's RQ-5A Hunter air vehicles.

* Meanwhile, IAI is close to finalising a deal with the Indian defence ministry for advanced UAV systems for use by the country's army during border surveillance operations. The deal, worth roughly $230 million, is expected to cover the delivery of about 50 Heron and Searcher IIair vehicles equipped with payloads, including synthetic aperture radar sensors.



Source: Flight International