sentences:  These flights were operated by Saab 340 and BAe Jetstream 31 propjet aircraft in 30-seat and 19-seat configurations, respectively.This service is no longer operational.On the cargo side, National Airlines operated two Douglas DC-8-63CF's (N921R/N865F) and one Douglas DC-8-71F (N872CA) on scheduled and charter operations worldwide, and later replaced one of the DC-8-63CF's with a DC-8-73F (N155CA).