Thousands of aircraft MRO operations in the US and abroad may get increased scrutiny to ensure they are not used by terrorists looking to sabotage US aircraftduring routine maintenance and repairs.

A Transportation Security Administration (TSA) regulation proposed recently would for the first time enable the agency to inspect MRO facilities. On TSA advice, the Federal Aviation Administration (FAA) could then suspend a facility’s operating license.

Commercial and smaller recreational aircraft undergo maintenance and repairs at more than 4,200 facilities across the US as well as at 700 facilities outside the US, in countries such as France, Germany, China, Singapore, Malaysia, India, Egypt and Jordan. But it is unclear how the TSA would deal with overseas facilities as it has no authority outside of the US.

The TSA says the greatest danger is posed by MRO facilities that are air-side, or next to airports because a terrorist could take control of an aircraft. TSA assistant administrator Lee Kair said the new requirement “guards against the potential threat of an aircraft being destroyed or used as a weapon.”