(CNN) -- The underwater search for Malaysia Airlines Flight 370 is on hold -- and likely will be for at least four days -- because of a malfunctioning part on the submersible Bluefin-21 and a broken transponder on the Bluefin's mothership, the U.S. Navy's deputy director of ocean engineering said.
The Bluefin-21 currently is the only submersible looking for the Boeing 777, which has been missing since March 8.
The Bluefin-21 and the transponder were damaged earlier this week when the vehicle was being hoisted onto deck of the Australian vessel Ocean Shield. The vehicle struck the navigation transponder, which extends over the side of the ship, said Michael Dean, the U.S. Navy's deputy director of ocean engineering.
Damage to the Bluefin-21 was repaired. But in subsequent tests, operators said the acoustic communications link on the Bluefin-21 and the navigation transponder on the Ocean Shield's were malfunctioning.
No spare parts for either device were on the ship, Dean said.
Under a best-case scenario, it will take another four or five days to get parts to the ship. But it could take longer if the Ocean Shield has to return to port, Dean said.