The Saunders-Roe SR.N5 (or Warden class) was a medium-sized hovercraft which first flew in 1964. It was the first production-built hovercraft in the world. A later "stretched" variant of the SR.N5 was produced in greater numbers as the SR.N6.14 SR.N5s were built, seven of them by Bell Aerosystems under licence in the United States as the Bell SK-5. Some of the SK-5 production became military Patrol Air Cushion Vehicle (PACV). At least two Bell SK-5s were used for civilian work.