Satchel Corso, 25, was arrested about 9:30 p.m. within the 107th Precinct, which covers neighborhoods including Kew Gardens Hills and Fresh Meadows, according to the NYPD.
He is expected to be charged with criminal possession of a weapon, defacing a weapon, and criminal possession of a controlled substance, police said.
Details about his weapon or how much cocaine he had were not immediately available.
Corso had only worked for the MTA for the past two weeks as a probationary employee on his way to becoming a conductor, a transit spokesman said.
He has been fired, the spokesman added.