The Israel Aerospace Industries (IAI) has allegedly advised operators not to fly some Boeing 737 freighters converted by the aerospace manufacturer pending a review of a fix that it has submitted for certification by the CAA of Israel. IAI had previously said it had a potentially unsafe design issue in some of the converted aircraft.

IAI has recommended all operators of its converted Boeing 737 freighters to ground the aircraft after it detected an “apparent irregularity” in the production process of a rigid barrier installed in some of the total 47 converted 737s delivered to customers worldwide, Reuters reported.

IAI, a major aerospace manufacturer within the commercial market stated on December 11, it had come up with an “interim solution” to the design issue. The fix has been reviewed and is expected to be approved by the national aviation authority, the state-owned company said.

According to IAI, the rigid barrier installed on some aircraft, in front of the cargo cabin, is an additional safety feature designed to provide emergency support under extraordinary conditions. The company’s testing found that the part was not working as supposed to and that the issue “may limit the way the aircraft can be safely loaded for flight.”

“The rigid barrier does not affect flight under normal conditions,” the company stressed to Reuters. “To the best of IAI’s knowledge, there has never been a flight incident in connection with the rigid barrier on these 737 aircraft.” IAI is now waiting for an AD to be issued by the CAAI in the next few days, allowing the grounded freighters to resume flights with the implemented fixes.

It is not known how many operators currently fly IAI’s converted Boeing 737 freighters, one airline that has been affected is Qantas Airways. The Australian airline has already taken all four of its 737-300 freighters out of service. The aircraft are used on domestic cargo routes by the airline’s Sydney-based subsidiary Express Freighters Australia on behalf of Qantas Freight.