Philadelphia ? An assembly line worker charged with vandalizing a military helicopter at a Boeing plant was upset about a job transfer and cut a bundle of about 70 electrical wires during his last shift on the Chinook line, federal investigators said Tuesday.

Matthew Kevin Montgomery, 33, of Trevose, had worked at the plant near Philadelphia for about 18 months before his arrest Monday, nine days after the H-47 Chinook aircraft was disabled.

Authorities say he is not currently a suspect in a separate act of vandalism on another helicopter at the plant, in which a suspicious washer was found.

Montgomery continued to work at the plant, where he made $19.10 an hour working the second shift, until meeting with federal investigators Monday, when he allegedly confessed.

U.S. Magistrate Judge Henry Perkin agreed at a hearing Tuesday to release Montgomery on $25,000 bail and ordered him to live with his parents in Southampton, undergo a mental health exam, and have no contact with Boeing or its employees.

“He’s very concerned and very remorseful,” said public defender Mara Meehan. “He’s been pretty upset, which is one reason why concerns have been raised about mental health.”

He admitted cutting the wires on the morning of May 10, according to an arrest affidavit. The helicopter would not have been able to fly with the cut wires, investigators said.

The production line was shut down early last week after the vandalism was discovered by workers inside the Ridley Park plant. Federal officials handed out fliers to workers, offering a $5,000 reward for information.

The Chinook is the Army’s workhorse aircraft, used to move troops and supplies. Boeing is producing new Chinooks for the Army, as well as updating older models.