Hawker Siddeley Harrier and better equipped for air defence, to replace their AV-8S Harriers; this investigation did not progress to a purchase. The last first-generation Harriers were retired by Thailand in 2006. Hawker Siddeley Harrier The Hawker Siddeley Harrier, developed in the 1960s, is the first of the Harrier Jump Jet series of aircraft. It was the first operational close-support and reconnaissance fighter aircraft with vertical/short takeoff and landing (V/STOL) capabilities and the only truly successful V/STOL design of the many that arose in that era. The Harrier was developed directly from the Hawker Siddeley Kestrel prototype aircraft, following the cancellation of a
McDonnell Douglas AV-8B Harrier II to the Lightning II would save $1 billion. After entering service in the mid-2010s, the F-35B will start to replace the AV-8B in 2016, with the AV-8B expected to continue service until 2025. Meanwhile, the AV-8B will receive revamped defensive measures, updated data-link capability and targeting sensors, and improved missiles and rockets, among other enhancements. The AV-8B Harrier II is a subsonic attack aircraft of metal and composite construction that retains the basic layout of the Hawker Siddeley Harrier, with horizontal stabilizers and shoulder-mounted wings featuring prominent anhedral (downward slope). The aircraft is powered by a single Rolls-Royce Pegasus turbofan