HALIFAX — The final report on the investigation into the crash of Swissair Flight 111 is to be released next month, more than four years after the disaster that left all 229 aboard dead.

The Transportation Safety Board of Canada, which conducted the massive inquiry, informed relatives of the victims this week that the report is being released March 27. "I know this is not going to be a pleasant thing for most people," Myles Gerety, head of a families group, said in an interview Thursday.

Gerety, whose brother Pierce died in the crash, said many families members are expecting to hear that the aircraft's onboard entertainment system was the likely cause of the disaster.

The system was identified early in the investigation as a possible cause of the electrical failure that led to a loss of control of the MD-11 jet.

"The betting is that that's probably a cause, which is completely ironic and horrible," Gerety said from Bridgeport, Conn.

"It just seems like a total, stupid waste. If it is the entertainment system, I'm going to be really upset."

In its Feb. 24 letter to family members, chief investigator Vic Gerden said those who can be in Halifax on March 27 will be given a private briefing on the findings more than two hours before the general release of the report. No advance copies will be provided.

For those unable to travel to Halifax, additional briefings will be given in New York, Los Angeles, Geneva and Paris in the weeks following.

Gerety added that the safety board could have provided more notice to families to allow them to make travel plans.