sentences:  Boulton Paul Bittern
  
  The Boulton Paul Bittern was a 1920s British night-fighter aircraft built by Boulton Paul Limited of Norwich, named after the marsh bird of the same name.Designed to Air Ministry Specification 27/24, which called for a single-seat night fighter for use against enemy bomber aircraft, the Bittern design was unusual for its time in that it was a twin-engined shoulder wing monoplane rather than a single-engine biplane.