Jbgarrison wrote:VTOL = Vertical Take Off
OR Landing
STOL = Short Take Off
OR Landing
Not that this little detail is that important to the discussion.
Also, VTOL is not used to describe helicopters as that would be redundant.
While wikipedia is not necessarily a reliable source, it does read this:
"VTOL is an abbreviation for Vertical Take-Off
and Landing aircraft. See also V/STOL. [[Vertical
and/or Short Take-Off and Landing]] This classification 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. Autogyros, balloons, airships and rockets are not normally considered VTOL, but may be termed 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) mode. 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.
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."
Therefore to call a helicopter a VTOL aircraft is not redundant because that is it's classification.