Mayor Bill de Blasio took an NYPD helicopter from Prospect Park to Long Island City, a spokesman said. View Full Caption Alexandra DiPalma

PARK SLOPE — Mayor Bill de Blasio used an NYPD helicopter for an 8-mile trek from Prospect Park to Long Island City during Friday evening rush hour, a spokesman said Monday.

Onlookers were puzzled to see the police chopper blowing clouds of dust off a baseball field in Prospect Park at 5:15 p.m. Friday, Patch first reported.

Nypd helicopter in prospect park ðŸ¤” pic.twitter.com/aQFQb08lBy — Alexandra DiPalma (@LSDiPalma) October 14, 2016

The mayor's press office did not immediately respond to a request for comment Monday morning, but spokesman Eric Phillips said on Twitter that de Blasio was in Brooklyn "for meetings" and took the bird to an event in Long Island City.

@joshrobin was in BK for meetings - he didn't land there. Left from there for an LIC event. — Eric Phillips (@EricFPhillips) October 17, 2016

The mayor's public schedule Friday included a 6:30 p.m. speech at an electricians union's new training center.

The NYPD declined to elaborate on the trip.

"The security and transportation of the mayor are determined by the NYPD," said John Miller, the NYPD's deputy commissioner for intelligence and counterterrorism, in an emailed statement. "We do not discuss the specifics of security."

The Prospect Park Alliance did not respond immediately to a request for comment.

Social media posts indicated that the helicopter landed on the Long Island City waterfront, roughly two miles west of the electricians union event.

Google Maps lists the trip from Prospect Park to the union event as about 30 minutes by car, an hour on public transportation, or about 50 minutes via bicycle.

The mayor has used helicopters to venture to Queens in the past. In 2015 he took one to visit the Sandy-damaged Rockaways, and a spokeswoman said then that the mayor only uses helicopters when "it’s impossible to get from one place to another in time allotted," the Daily News reported.

After facing criticism for being late to several events, de Blasio told told NY1 in 2015 that helicopters are "not my thing" and that he prefers "to be on the ground."

De Blasio is routinely criticized for driving the 12 miles from Gracie Mansion on the Upper East Side to his beloved exercise sessions at the YMCA in Park Slope, Brooklyn, a practice he's defended as essential to helping him do his job effectively.