Northrop Grumman has received an additional $143 million from the US Air Force to cover an overrun on Global Hawk unmanned air-vehicle development caused principally by higher than expected costs to engineer the airframe of the enhanced RQ-4B version.

The overrun on engineering and manufacturing development has pushed the average procurement cost of the UAV up by 18%, triggering a so-called Nunn-McCurdy unit-cost breach and requiring the US Department of Defense to notify Congress.

A source says two-thirds of the overrun is due to higher than estimated non-recurring engineering costs at Aurora Flight Sciences for the stretched fuselage and at Vought Aircraft Industries for the longer wing. The rest is blamed on costs and unfunded requirements arising from operational use of the Global Hawk technology demonstrators in Iraq. The first RQ-4B, or Block 20, Global Hawk is in production and will fly next year.

The US Defence Acquisition Board, meanwhile, has approved release of $85 million to continue development of the Global Hawk and its Advanced Signals Intelligence Programme and Multi-Platform Radar Technology Insertion Programme payloads. Another $50 million in procurement funding has been cleared to avoid a break in production, with the remainder to be released on successful completion of the Block 20 wing static test in June. The resulting acquisition decision memorandum also supports the deployment of two RQ-4A Block 10 initial-production UAVs to Iraq for an operational assessment to be completed by March .

GRAHAM WARWICK/WASHINGTON DC

Source: Flight International