After a pandemic hiatus, the Transportation Security Administration is relaunching a self-defense training course for flight attendants and pilots that includes suggestions for deterrence and ideas on the most vulnerable places to hit an attacker.

The move comes as coronavirus restrictions are waning and airline employees have reported thousands of instances of unruly behavior by passengers this year, ranging from refusals to wear masks to assaults.

The voluntary, hands-on training is meant to prepare crew members to handle “potential physical altercations,” according to the TSA. It includes help recognizing suspicious behaviors, gauging the seriousness of incidents and tools for deterring passengers who might become a threat.

It also includes techniques for searching cabins for bombs, maneuvers pilots might take to protect the aircraft, defenses against “edged or contact weapons,” and the most effective ways to strike or restrain attackers, according to federal law. A TSA video featuring one of the courses includes flight attendants practicing gouges to the eyes and kicks to the groin.

“While it is our hope that flight crew members never have need for these tactics, it is critical to everyone’s safety that they be well-prepared to handle situations as they arise,” said Darby LaJoye, the TSA’s top official. With incidents of unruly behavior “on the rise, TSA remains committed to equip flight crews with another tool to keep our skies safe,” the agency said in a statement.

Sara Nelson, president of the Association of Flight Attendants-CWA, who has taken the training, said the course should be mandatory rather than voluntary, and taken repeatedly.

Given a rise in onboard incidents, Nelson said, the program’s resumption in July “should send a message to the public as well that these events are serious and flight attendants are there to ensure and direct the safety and security of everyone in the plane.”

The Federal Aviation Administration last month released details of a December incident that shows the depths of troubles flight crews can face.

The agency said a passenger on a Delta Air Lines flight from Honolulu tried to open the cockpit door, then hit a flight attendant in the face and pushed him to the floor. Flight attendants, helped by a customer, restrained the passenger with plastic handcuffs, but the individual slipped a wrist out and hit the Delta employee in the face again, the agency said. The passenger was taken into custody after landing, and the FAA has proposed a $52,500 civil penalty.