It took opposing papers on summary judgment and a judge’s partial ruling on the burden of proof to tee up a settlement in the last remaining wrongful death action seeking to hold United Airlines and its security subcontractor liable for allowing five armed terrorists to hijack Flight 175 on Sept. 11, 2001.

The family of former National Hockey League player and talent scout Mark Bavis reached an agreement with the airline on Monday for an undisclosed sum, cutting off a trial scheduled for November at which Donald Migliori, the Bavis family lawyer, had promised a full exploration of a flawed airline security system that allowed 19 men to commit mass murder by seizing and crashing four airplanes.