Northrop Grumman and EADS, the main parties behind the Euro Hawk programme, have defended the unmanned air vehicle's performance after criticism from its customer, the German air force, which led to the cancellation of the procurement worth up to €1 billion ($1.3 billion).
The two companies also believe they have developed an "affordable and achievable plan" to convince the customer to change its mind.
Germany pulled the plug on Euro Hawk earlier in May, citing problems with the RQ-4 Global Hawk-derived high-altitude, long-endurance UAV's flight control system and "significant certification issues" preventing the completion of its test programme.
However, in a joint statement, Northrop and EADS deny the programme has encountered any setbacks. "The full Euro Hawk system, including the mission control system and the sensor, has performed flawlessly and safely throughout the entire flight test programme.
"Media reports that indicate there are challenges with the aircraft's flight control system, as well as excessive costs associated with completing airworthiness certification, are inaccurate."
It will continue to work with the customer, it adds, to "provide an affordable and achievable plan to complete flight testing of the initial asset and the eventual production and fielding of the full system of four additional aircraft".