sentences:  The aircraft was a Lockheed C-130H Hercules more than fifty years old, with tail number 65-0968 and serial number 4110, that had been converted to a WC-130H for weather reconnaissance operations.It was assigned to the United States Air National Guard and operated by the 156th Airlift Wing of the Puerto Rico Air National Guard.On 12 January 1981, the Boricua Popular Army ("Ejército Popular Boricua"), a Puerto Rican separatist organization, carried out multiple bombings at the Muñiz Air National Guard Base.