Hawker Siddeley Harrier single lever added in the cockpit. For horizontal flight, the nozzles are directed rearwards by shifting the lever to the forward position; for short or vertical takeoffs and landings, the lever is pulled back to point the nozzles downwards. The Harrier has two control elements not found in conventional fixed-wing aircraft: the thrust vector and the reaction control system. The thrust vector refers to the slant of the four engine nozzles and can be set between 0° (horizontal, pointing directly backwards) and 98° (pointing down and slightly forwards). The 90° vector is normally deployed for VTOL manoeuvring. The reaction control
McDonnell Douglas AV-8B Harrier II a demonstration of the Hawker Siddeley Harrier on the Italian Navy ("Marina Militare") helicopter carrier , the country began investigating the possibility of acquiring the Harrier. Early efforts were hindered by a 1937 Italian law that prohibited the navy from operating fixed-wing aircraft because they were the domain of the air force. In early 1989, the law was changed to allow the navy to operate any fixed-wing aircraft with a maximum weight of over 3,300 lb (1,500 kg). Following a lengthy evaluation of the Sea Harrier and AV-8B, an order was placed for two TAV-8Bs in May 1989. Soon, a