An Airbus (AIR.PA) A400M military transport plane crashed outside Seville on Saturday, killing four test crew and prompting Britain and Germany to ground Europe's new troop and cargo carrier.
The aircraft was due to be delivered to another NATO customer, Turkey, and was on its maiden test flight when it crashed in a field one mile (1.6 km) north of Seville's San Pablo airport. It was the first ever crash of an A400M.
Airbus said four Spanish employees had been killed and two surviving crew were in hospital in serious condition.
The newspaper El Pais said the crew had detected a fault and asked permission to land, but hit an electricity pylon while attempting an emergency landing.
Tracking data from the Flightradar24 website indicated the plane had wheeled to the left before coming down.
An Airbus spokesman declined to comment on possible causes. Airbus said it had sent a team to investigate.
The crash delivers a fresh blow to Europe's largest defense project, which is still struggling to overcome delays and cost overruns that led to a bailout by European governments in 2010.
Britain and Germany said they were suspending A400M flights while they awaited more information on what caused the crash.
A plume of black smoke rose from the site, where hardly anything was left of the plane amid black, scorched earth.
Prime Minister Mariano Rajoy, speaking to journalists near the site, asked for maximum transparency from Airbus on the reasons for the crash.
"An incident like this is not the best for our industry ... It remains to be seen if it was purely circumstantial or if a mistake was made," he said, adding that the Spanish defense minister would meet his German and French counterparts on Sunday to discuss the incident.
The A400M Atlas was developed for Spain and six other European NATO nations - Belgium, Britain, France, Germany, Luxembourg and Turkey - at a cost of 20 billion euros ($22 billion), making it Europe's biggest single arms contract. It entered service in 2013 after a delay of more than three years.
The launch nations have ordered a total of 170 A400Ms. Malaysia, the plane's only export customer, has ordered four.
The planes, costing just over 100 million euros each, are assembled in Spain, which has long sought to emerge from France and Germany's shadow within Europe's largest aerospace company.
Problems in delivering the planes on time, and with all the required military features on board, resurfaced last year, triggering a management shake-up and more financial charges.
After receiving stinging criticism from both Germany and Turkey over the delays, Airbus hoped it was finally turning the corner, with an executive saying last week that it hoped soon to get a second export customer soon..
There was no immediate word on whether the accident would result in the halting of test flights, which could mean further delivery delays, nor whether the A400M would be grounded by its other current operators: France, Malaysia and Turkey.
Designed to put troops and heavy equipment into remote battlefields or carry out humanitarian missions, the aircraft was intended to fill a gap between the smaller Lockheed Martin (LMT.N) C-130 Hercules and the Boeing (BA.N) C-17 cargo jet.
It is powered by the West's largest turboprop engines, supplied by Britain’s Rolls-Royce (RR.L), France’s Safran (SAF.PA), MTU Aero Engines of Germany (MTXGn.DE) and Spanish aerospace firm Industria de Turbo Propulsores (ITP). Problems in developing these were blamed for much of the delay.