The NTSB is considering taking over the crash investigation AND altering the findings . . .
The NTSB is a United States entidy, it hardly has jurisdiction "to take over" an accident investigation in Thailand and assign official probable cause. The NTSB may be
invited by the Kingdom to send representatives to
help in the investigation.
Filing a lawsuit in the United States for damages has jurisdictional constraints, because the only thing "American" is the airplane. And the MD80 has had a proven track record for many decades. So, unless the plaintiffs can identify a "design flaw" of the airplane which directly contributed to this accident, then the law suit will have no merit. US courts have no jurisdiction of foreign registerd airplanes crashing in foreign lands, nor do they have jurisdiction of foreign airlines that do not overfly U.S. airspace and do not carry passengers or cargo into the U. S.