The NYPD says the officer arrived in Moscow Tuesday and it's not clear how long he will stay.
He will learn about the bombing, which killed 35 people, gathering information to help New York guard against a similar attack. The detective has been to Moscow previously to learn about the subway station bombing in 2010.
The detective is normally assigned to Tel Aviv as part of a program where some NYPD officers are stationed around the world to help learn from overseas incidents.
Monday's explosion at the international terminal at Moscow's largest airport also wounded 180 people. Authorities in part blamed lax security.