When Biddeford City Councilor Bradley Cote calmly announced his resignation, put on his jacket and walked out of council chambers Tuesday night in the middle of a council meeting, the looks on the faces of his fellow board members said it all.

“I did not see that coming. I don’t think anyone saw that coming,” said Mayor Alan Casavant. “If you looked closely, my jaw was probably on my desk.”

Cote’s resignation followed a council vote to spend city money to trim trees deemed an obstruction at the municipal airport, and another against spending $27,000 on an impact study of the airport. Cote said he supported the impact study because he felt councilors needed more information before spending on projects at the city-owned facility.

The unassuming councilor consistently questioned how taxpayer money was spent during his three years on the panel. He said the airport impact study vote marked a breaking point after months of frustration about a council he says has based decisions on gut feelings rather than facts.

“Some people look at it like I’m quitting, but I don’t really feel that way,” he said. “I don’t feel comfortable making decisions without facts and data. They’ll need to find someone else do to that.”

It will be up to Casavant to appoint, and the council to confirm, someone to fill out the remainder of Cote’s second term, which ends in November. The mayor has 30 days to make the appointment.

Cote’s departure is the third time a councilor has resigned in the past two decades, but the first in the middle of a meeting. In 2012, David Flood resigned shortly after being elected because of a job conflict. In the late 1990s, Roch Angers resigned because of a work commitment.

Cote, 34, grew up in Biddeford and said he decided to run for a council seat three years ago to give back to and improve his hometown. From the start, the young councilor became known for a calm and friendly attitude, thorough research and thoughtful but probing questions, according to other city councilors. An auditor and compliance specialist by day, Cote brought an analytical presence to the council.

“He’s a very smart individual and a great guy,” said council President John McCurry. “He always had good questions and he was always prepared.”

Cote said Wednesday that he wasn’t second-guessing his decision to step down. He had not planned to resign going into the meeting, he said, but had grown increasingly frustrated with how the council was making decisions about spending large amounts of money. In December, he voted against spending $700,000 from the city’s industrial park fund to buy a parcel of land on Elm Street.

With both the airport tree-trimming expenditure and the Elm Street land purchase, Cote said he did not feel the council had sufficient information to make informed decisions.

“I’ve always been a numbers geek. I’ve always wanted data and facts to make educated decisions and we haven’t been doing that a lot lately,” he said. “I’d come home from meetings and bang my head against the wall. I didn’t want to be part of it anymore.”

The City Council voted Tuesday to authorize the city manager to accept more than $900,000 in federal and state funds to trim or remove trees that the Federal Aviation Administration has said could obstruct air traffic. The city would contribute $48,000 – 5 percent of the project’s total cost.

Only Cote and Councilor Clement Fleurent voted against the project. Both also supported the economic study opposed by the council majority.

Fleurent said he understands Cote’s frustrations, but is sad to see him leave because of them.

“He’s a smart kid. We could not ask for any better,” he said. “I looked at him as a potential future mayor because of his wisdom and thorough study of the issues. He’s going to be hard to replace.”

McCurry and Casavant say they don’t fully understand why Cote resigned and disagreed with his contention that the council fails to gather sufficient information before making financial decisions. But they also said his absence leaves a hole on the council that will be hard to fill.

“By resigning, he took away a particular point of view and voice from the council. To see him remove himself is disappointing,” Casavant said. “I can understand the frustration to a certain degree, but we all get frustrated in politics.”

Casavant said he will try to find a replacement who can learn the ropes quickly as the council prepares to tackle the municipal budget.

“My objective is to find someone who will mesh with this council but also have a distinctive voice,” he said. “They need to be able to jump in and hit the ground running.”

For his part, Cote said he will not run for City Council again.

“My time in public service has come to a close,” he said.