What are the three stages of takeoff? Although the takeoff and climb is one continuous maneuver, it will be divided into three separate steps for purposes of explanation: 1.) takeoff roll; 2.) lift-off; and 3.) initial climb after becoming airborne. Reduced take-off and landing, or RTOL, is an intermediate stage for large aircraft unable to achieve economic vertical or short take-off and landing within the limits of existing technology. Reduced take-off can be achieved by modifications to existing designs, with additional flaps and slots and jetstream ducting, or by variations on existing design concepts, instead of the radical changes necessary for STOL. Catapult launch and arrested recovery CATOBAR (catapult assisted takeoff but arrested recovery) is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier. Under this technique, aircraft are launched using a catapult and land on the ship (the recovery phase) using arrestor wires. Although this system is more costly than alternative methods, it provides greater flexibility in carrier operations, since it allows the vessel to support conventional aircraft. Alternate methods of launch and recovery can only use aircraft with STOVL or STOBAR capability. Short Take Off But Arrested Recovery STOBAR (Short Take Off But Arrested Recovery) is a system used for the launch and recovery of aircraft from the deck of an aircraft carrier, combining elements of both STOVL (Short Take-Off and Vertical Landing) and CATOBAR (Catapult Assisted Take-Off But Arrested Recovery). Spacecraft (HTHL) Horizontal takeoff, horizontal landing (HTHL) — is the mode of operation for the first private commercial spaceplane, the two-stage-to-space Scaled Composites Tier One from the Ansari X-Prize SpaceShipOne/WhiteKnightOne combination. It is also used for the upcoming Tier 1b SpaceShipTwo/WhiteKnightTwo combination. A prominent example of its use was the North American X-15 program. In these examples the space craft are carried to altitude on a “mother ship” before launch. The failed proposals for NASA Space Shuttle replacements, Rockwell X-30 NASP used this mode of operation but were conceived as single stage to orbit. The Lynx rocketplane was a suborbital HTHL spaceplane developed by XCOR Aerospace that was slated to begin atmospheric flight testing in late 2011. However, after numerous delays, XCOR Aerospace went bankrupt in 2017 without finishing a prototype. Reaction Engines Skylon, a design descendant of the 1980s British HOTOL (“Horizontal Take-Off and Landing”) design project, is an HTHL spaceplane currently in the early stages of development in the United Kingdom. Both the Lynx rocketplane and SpaceShipTwo have been proffered to NASA to carry suborbital research payloads in response to NASA’s suborbital reusable launch vehicle (sRLV) solicitation under the NASA Flight Operations Program. An early example was the 1960s Northrop HL-10 atmospheric test aircraft where the HL stands for “Horizontal Lander”. Vertical takeoff and landing Different terms are used for takeoff and landing depending on the source of thrust used. VTVL uses rockets, whereas VTOL uses air, propelled via some kind of rotor system. Aircraft Vertical Take-Off and Landing (VTOL) aircraft includes fixed-wing aircraft that can hover, take off and land vertically as well as helicopters and other aircraft with powered rotors, such as tiltrotors. The terminology for spacecraft and rockets is VTVL (vertical takeoff with vertical landing). Some VTOL aircraft can operate in other modes as well, such as CTOL (conventional take-off and landing), STOL (short take-off and landing), and/or STOVL (short take-off and vertical landing). Others, such as some helicopters, can only operate by VTOL, due to the aircraft lacking landing gear that can handle horizontal motion. VTOL is a subset of V/STOL (vertical and/or short take-off and landing). Besides the ubiquitous helicopter, there are currently two types of VTOL aircraft in military service: craft using a tiltrotor, such as the Bell Boeing V-22 Osprey, and aircraft using directed jet thrust such as the Harrier family. In the civilian sector currently only helicopters are in general use (some other types of commercial VTOL aircraft have been proposed and are under development as of 20