WASHINGTON D.C.The Federal Aviation Administration (FAA) on Thursday issued a new safety directive for all Boeing 737 Max airplanes and some other 737 planes to address a potential issue with reduced fire suppression capabilities.

The FAA said planes may have a failed electronic flow control of the air conditioning packs that vent air into the cargo hold from other areas of the plane. The directive prohibits operators from transporting cargo in the cargo hold if airplanes are operating with this condition unless they can verify items are nonflammable and noncombustible.

The airworthiness directive impacts 663 airplanes registered in the United States and approximately 2,204 worldwide.