A Porter Airlines plane, advised by the island airport to divert to Pearson, instead landed on the island after an 11 p.m. curfew, when the control tower was unstaffed — raising safety concerns among nearby residents.

Details of the Sept. 18, 2008, incident emerged Thursday at the Toronto Port Authority’s annual general meeting, amid accusations that board minutes detailing safety concerns from that night were altered.

Although it may surprise some that planes would land without aid from a control tower, Canada’s air navigation service provider says it’s standard practice at most of Canada’s 700-plus airports, only 41 of which even have control towers.

But when a commercial plane lands after hours at the island airport, it could be subject to a $5,000 fine under a curfew agreement. Porter has been fined, though a review is underway so fines are accruing.

“Why have board minutes been cleansed, and effectively edited by board members who weren’t even present for the initial discussion?” Councillor Adam Vaughan asked at yesterday’s meeting, leading the charge along with other airport opponents. “Why is there a cover-up?”

“That’s not true,” replied port authority chair Mark McQueen, who later told reporters the minutes were changed to eliminate “verbosity.” Earlier drafts were written like a court transcript, McQueen said, with repeated instances of “he said, she said.”

The minutes from 2008, approved in June, now reflect decisions taken and the rationale, he added.

The revisions came after the board of the arm’s-length federal agency was expanded to nine members late last year. Former member Doug Reid, whose term expired last month, said key details were eliminated.