In the mid-1980s, several U.S. Navy E-2Cs were made available to the U.S. Coast Guard and the U.S. Customs Service for counter-narcotics (CN) and maritime interdiction operations (MIO). This also led to the Coast Guard building a small cadre of Naval Flight Officers (NFOs), starting with the recruitment and interservice transfer of Navy flight officers with E-2 flight experience and the flight training of other junior Coast Guard officers as NFOs. A fatal aircraft mishap on 24 August 1990 involving a Coast Guard E-2C at the former Naval Station Roosevelt Roads in Puerto Rico prompted the Coast Guard to discontinue flying E-2Cs and to return its E-2Cs to the Navy. The U.S Customs Service also returned its E-2Cs to the Navy and concentrated on the use of former U.S. Navy P-3 Orion aircraft in the CN role.