The British built Harrier is the most successful vertical take off warplane in history. But it's a complex beast and dangerous to fly. The most energetic users of Harriers, the U.S. Marine Corps, have lost a third of their 397 Harriers to accidents in the last 31 years. There have been 143 accidents involving Harriers, and 45 Marine pilots have died as a result. Five Harriers have been lost in combat, along with two pilots. All this was during the Persian Gulf war. The Harriers put out a lot of heat in many different directions when hovering, and this made them ideal targets for Iraqi portable anti-aircraft missiles. The Harrier is also serving in Afghanistan. The marines still have 154 Harriers, and they are to be replaced by a vertical take off version of the new F-35. The new aircraft is designed to be safer to operate than the Harrier. The marines have constantly reduced the Harriers accident rate, but the F-16, also a single engine fighter, has an accident record half that of the Harrier. The newer F-18 has an accident rate that is only about 30 percent that of the Harrier.