As a deputy Chicago aviation commissioner, Bill Helm’s job was to oversee city truck drivers who patch, plow and preen O’Hare Airport’s maze-like network of surface roads, taxiways and landing strips.

Now, Helm is part of another labyrinth: a corruption investigation that’s been zigzagging across the political landscape, with federal investigators having raided southwest suburban village halls and appearing to hone in on a host of politicians and clout-heavy businessmen.

Helm isn’t well known, like some of the politicians he works for. But for decades, he’s been a old-school Chicago operator who has marshaled “volunteers” — often city employees — to circulate petitions and get out the vote for politicians. He also has used his contacts with bar and restaurant owners to hold fundraisers for campaigns, sources say.

He has gotten one plum government job after another, despite a history of disciplinary actions taken against him. In his latest job, at O’Hare, he got into trouble after being accused of allowing one of his workers to bring his wedding party onto the airfield for photos — without security clearance. In August, Helm abruptly resigned from that post, which paid him more than $125,000 a year.

Helm, 55, who hasn’t been charged with any crime, has deep ties to politicians as well as business owners who need friends in government — some of who’ve drawn the interest of the FBI and the IRS.

Reached at home, he declined to answer questions, saying, “Just let it play out.”

His name has surfaced in search warrants relating to the investigation, records show. The first one was used when the FBI searched the Springfield offices of state Sen. Martin Sandoval on Sept. 24. Another came two days later, when the feds hit the tiny southwest suburb of McCook and the offices of its mayor, Jeff Tobolski, who is also a Cook County commissioner.

The Sandoval warrant doesn’t give any specifics on Helm, who has worked on at least one campaign with Sandoval.

As for Tobolski, Helm and the county commissioner “are very close, political allies,” according to a source.

Helm also is a longtime friend of Tobolski’s top county aide, Patrick Doherty, his chief of staff.

Doherty has been a sales consultant for SafeSpeed, LLC — a contractor that operates red-light cameras in many suburbs and has been a focus of federal investigators, the Sun-Times has reported. SafeSpeed has denied any wrongdoing, and neither Helm nor the company would say whether he has been affiliated with SafeSpeed.

Helm’s relationship with Doherty dates to when both worked for the Cook County Forest Preserve District, sources said. Helm worked for the district from 1991 to 2003 and again from 2007 to 2011.

Helm is a longtime friend of Rick Heidner, a video-gaming magnate who was named in search warrants as part of the investigation. Heidner hasn’t been charged with any crime and says he’s done nothing wrong.

Until recently, Helm also was a sales agent for Heidner’s Gold Rush Gaming, also named in the search warrants, according to records and interviews.

Heidner says Helm was brought in to pursue “contracts” with bars and other establishments in Chicago to use Gold Rush’s video-gaming machines — contingent on a change in the law that now bans video gaming in the city. He also has done work for Gold Rush in the suburbs, a source says.

Heidner says he doesn’t know why federal investigators would be interested in Helm. Heidner says his own lawyer was told by federal prosecutors that Heidner isn’t a target.

The U.S. attorney’s office won’t comment.

After Heidner’s name surfaced in the Sandoval warrant, Gov. J.B. Pritzker’s administration announced it wouldn’t sell state-owned land in Tinley Park that was needed for a southwest suburban “racino.” The partners in that racino included Heidner. Pritzker’s move also came after the Chicago Tribune published a report linking Heidner to a banking family with reputed mob ties.

Helm also has ties to a cigar bar in Countryside — Casa De Montecristo — that’s a hangout for some of the movers and shakers who have attracted the interest of federal investigators. Helm held a campaign fundraiser for state Senate President John Cullerton at the cigar lounge in 2013, according to Cullerton. Tobolski was involved in that event, according to a source, and the cigar lounge contributed $3,500 to Cullerton’s campaign fund that year.

“That’s like a political club,” says another source familiar with the cigar lounge, also frequented by Cicero Town President Larry Dominick. “A lot of political guys go there. They sit there, smoke cigars and make deals.”

Sandoval also has gotten campaign money from the cigar lounge.

Another onetime regular of the cigar bar is Omar Maani, an investor in SafeSpeed. Business associates of Maani believe he is cooperating with federal authorities in the ongoing investigation, and the Sun-Times has reported he regularly entertained and socialized with political figures, including Tobolski, linked to the investigation,

Maani also runs Presidio Capital, which has gotten millions in taxpayer dollars to build affordable housing in Cicero and Summit and has drawn the attention of federal investigators.

The FBI and Chicago’s inspector general’s office interviewed O’Hare workers about claims that Helm pressured them to work on political activities, often on city time.

Helm faces a federal lawsuit by city workers over those allegations.

The workers are members of Teamsters Local 700. The union local’s leader at the time, Becky Strzechowski, wrote to members after the suit was filed, effectively taking management’s side and supporting Helm in the dispute.

Strzechowski resigned earlier this year, seven months before her mentor, longtime Chicago Teamsters boss John Coli Sr., pleaded guilty in an extortion case involving Cinespace Chicago Film Studios.

Helm started at O’Hare in 2014 when Mayor Rahm Emanuel was in office, and Helm helped Emanuel in his mayoral campaigns and, before that, when he ran for Congress, sources say.

Helm also helped the aldermanic campaigns of Emanuel’s ally and floor leader, Patrick O’Connor, the longtime Democratic boss of the North Side’s 40th Ward, sources said.

Emanuel didn’t respond to questions.

O’Connor says: “I’ve never . . . forced anyone to do political work.”

Helm has been a major part of O’Connor’s political operation in recent years. He got his start in politics, though, with the 47th Ward Democratic organization of former Chicago Park District boss Ed Kelly. Helm shifted his allegiance to former Ald. Gene Schulter when Schulter and Kelly split in 1987, sources say.

But Kelly, long retired, describes Helm as a Schulter guy.

Schulter didn’t return calls.

After Schulter retired from the Chicago City Council in 2011, Helm moved over to O’Connor — and the three 47th Ward precincts over which Helm and his brother held sway were moved into the 40th Ward as well.

A former high-ranking official of the Illinois Department of Transportation, Helm was hired by the city aviation department despite having been found by the state of Illinois’ in-house watchdog to have “engaged in approximately 41 hours of personal conversations on his personal telephone during work hours” over six months in 2011 and 2012 and to have “repeatedly used a state vehicle to visit and transport a non-state employee.”

Helm also got a red-light ticket in his state car, according to records that show he resigned.

At O’Hare, sources say Helm was facing heat for allowing a city truck driver who was involved in Helm’s political operation to bring his 2016 wedding party onto the airfield, without security clearance, for wedding photos.

That infraction “wasn’t the only thing” but was “a contributing factor” in Helm’s “abrupt” departure from the aviation department job, a source familiar with the investigation says.

That truck driver, who’s still working for the Chicago Department of Aviation, wouldn’t comment.