Steven Slater, dressed in a trim blue suit, appeared in a Queens courtroom for a brief hearing on charges of criminal mischief, reckless endangerment and trespassing after last month’s meltdown aboard a JetBlue Airways Corp. flight from Pittsburgh that had just landed at Kennedy International Airport.

He was working Aug. 9 when, he said, an argument took place with a rude passenger. After landing at JFK, he went on the public address system, swore at a passenger who he claimed had treated him rudely, grabbed a beer and exited via an emergency chute, prosecutors said.

Attorneys on both sides said a deal was being discussed. Slater will be evaluated and may qualify for an alternative sentencing program, which means he could face community service and counseling instead of jail.

Queens District Attorney Richard A. Brown said Slater’s willingness to be evaluated shows he’s taking the charges more seriously than he had in the past. Slater had spoken out after the incident, as his public opinion swelled and hundreds of thousands of fans online cheered him for standing up to the inhospitable world of airline travel.

The district attorney, speaking to reporters after the hearing, said it would behoove the public to take the Aug. 9 incident more seriously, noting the slide cost $25,000 to repair and the plane had to be taken out of service afterward, causing passenger delays.

“It’s no laughing matter,” he said.

Slater’s attorney, Daniel J. Horwitz, said his client was taking the matter very seriously and said he had been under tremendous pressure because of his terminally ill mother, recently deceased father, and health problems of his own. (Slater is HIV positive.) He said he was hoping prosecutors would take into account Slater’s “long-standing and well-regarded reputation in the industry.”

Horwitz said he hopes they can come to an agreement that favorably resolves the case, but he wouldn’t specify what he was looking for. Brown said if Slater is admitted for alternative sentencing, he could undergo a treatment program lasting weeks, but he said it depended on the outcome of the evaluation and he’s not ruling out the possibilty of jail time yet.

Slater, his head held high, left the court without speaking to the swell of reporters surrounding him. His publicist and attorney said he’s in good spirits and has spent the past few weeks in California with his ailing mother.

Slater resigned from JetBlue last week after about three years there; JetBlue said only that he was no longer an employee. Slater has spent nearly 20 years in the airline industry, but it’s not clear what he’s going to do now.

“Right now we want to get past the criminal issues. Then we’ll worry about the future,” publicist Howard Bragman said. “Obviously he will be unemployed until all this is resolved.”

JetBlue suspended Slater after the incident. It told employees in a memo that press coverage was not taking into account how much harm can be caused by emergency slides, which are deployed with a potentially deadly amount of force.