Spain's Defence Ministry has withdrawn flying permission for Airbus A400M planes in the production phase until an investigation determines the cause of a crash last weekend.
The crash near the southern city of Seville killed two pilots and two flight test engineers.
Minister Pedro Morenes told Spain's Onda Cero radio today that "it's not a good idea for those planes in production phase, and about to do tests, to fly without knowing what really happened with the (crashed) plane".
He said all precautions must be taken, adding that he had no details on the investigation's progress.
Four of the five countries that already have A400Ms - Britain, Germany, Malaysia and Turkey - have grounded the plane. France, which has six, said it will only use the aircraft in urgent operations.
The measure means that planes in the final stages of assembly in Seville will not be able to carry out test flights.
Mr Morenes said probes involving such planes are complicated and the need to know what happened as soon as possible should not interfere with the rigour necessary in a proper investigation.
He said human and technological factors would be taken into account but added that the possibility that the pilot might have manoeuvred the plane in the final moments to avoid a more serious accident may provide a clue to what happened.
"It appears that the pilot made a manoeuvre to try to avoid worse things happening in the accident," Mr Morenes said. He gave no further details.
Some media outlets cited Airbus Sevilla union representative Francisco Figueroa as saying that the pilot, by landing the plane in a field, apparently avoided crashing it into a nearby shopping centre and factories.
The permit suspension will not affect a planned A400M test flight from Toulouse, France, to Seville.
Fernando Alonso, the head of military aircraft at Airbus Defence and Space, is expected to take part in the test as a flight engineer in a symbolic show of confidence in the plane.
Mr Alonso took up his post in January after Airbus dismissed his predecessor following complaints by governments about continued delays in finishing the cargo plane whose rollout went billions over budget and years over deadline.
Seville is the final assembly point for the A400M - a 20 billion euro (£14 billion) programme that saw its first deliveries in 2013. Some 194 aircraft have been ordered by eight countries - including Spain - to replace their ageing Hercules fleets.
Also today, authorities are holding a funeral mass in Seville for the four dead.
An Airbus statement said it was too early to say how this would affect the delivery schedule for the planes.
"We are working very closely with the military authorities as well as our customers to manage this situation," the statement said.
The southern Andalusian justice department in Seville said the judge in charge of the crash probe, Ana Rosa Curra, had placed a secrecy order on investigations, meaning no details would be released officially for the time being.