Airbus said Wednesday that three of the four engines on an A400M military plane failed before it crashed near Seville, Spain last month, killing four people.

In a statement, Airbus Defense and Space says the faulty engines were confirmed by Spanish accident investigators after completing their preliminary analysis of the aircraft's digital flight data and cockpit voice recorders.

The crash May 9 killed two pilots and two flight test engineers. The crash remains under investigation.

Three of the hulking gray aircraft's four turboprop engines suffered what it called "power frozen" after lift-off, and failed to respond to the crew's efforts to regain control. A fourth engine responded normally. No other problems have been identified by the preliminary analysis.

Airbus says the A400M's eight-bladed turboprop engines are the most powerful in production. They are built by a consortium made up of Rolls Royce, Snecma, MTU and ITP.

The A400M can carry 116 fully equipped paratroopers or carry up to 37 tons of cargo, including armored vehicles and helicopters.

Last month Airbus sent a so-called Alert Operator Transmission notice to all operators of the giant airlifter, warning them of the need to perform checks of its Electronic Control Units before they are next flown.

Airbus said investigators' latest analysis is consistent with that AOT and doesn't call for any further recommendations.

Four of the five countries that already have A400Ms — Britain, Germany, Malaysia and Turkey — grounded the plane after the crash. France, which has six, says it will only use the aircraft in urgent operations.

The 20 billion euro A400M program saw its first deliveries in 2013. Some 174 aircraft have been ordered by eight countries — including Spain — to replace their aging military transport fleets. Twelve of the aircraft were delivered as of March, with Malaysia's air force being the most recent customer. A further five aircraft were due to be delivered to Germany this year, but Airbus has notified the German government to expect delays.