The lawsuit accuses Boeing Corp., Bell Helicopter Textron Inc. and Eaton Aerospace of negligence and recklessness.
The airplane-and-helicopter hybrid aircraft crashed at a military base outside Honolulu with 21 Marines and a Navy corpsman on board. Two Marines were killed, including Lance Cpl. Matthew Determan, 21, of Ahwatukee, Arizona.
His parents, Michael and Charlesa Determan, filed the lawsuit in federal court in Honolulu on Monday. Other defendants include unnamed government agencies and individuals the plaintiffs say they're unable to identify until attorneys are able to examine documents and interview witnesses.
Boeing and Bell Helicopter spokesmen referred requests for comment to the Marine Corps.
Marine Corps spokeswoman Capt. Sarah Burns said in a statement the Marines are committed to ensuring their aircraft are safe and that air crew who fly them are thoroughly trained. She said the Marines diligently investigate mishaps.
In November, a Marine Corps investigation found the MV-22 aircraft flew in sandy or dusty conditions for an extended period before its engine stalled. The stalled left engine then put the Osprey in an unavoidable freefall.
The probe said the pilots didn't violate any regulations or flight standards, but investigators found a proper risk assessment should have prompted the pilots to choose a different flight path or landing site to avoid dust or sand.
Investigators have recommended changes to help pilots make better decisions in similar situations.
The Osprey can take off and land like a helicopter, allowing it to go almost anywhere. Yet it can also fly as far and as fast as an airplane, giving it longer range than a traditional helicopter.
Determan was a member of the 15th Marine Expeditionary Unit based at Camp Pendleton in California. His aircraft had taken off from a Navy ship 100 miles offshore, and was flying to Oahu to drop off Marines for training on land, when it crashed.
This article was written by Audrey McAvoy from The Associated Press and was legally licensed through the NewsCred publisher network.