Airfoilsguy From , joined Dec 1969, posts, RR: Posted (8 years 10 months 2 weeks 5 hours ago) and read 4620 times:
I have always wondered why they call the landing gear the "main landing gear". Calling it that would seem to imply there is a reserve landing gear. There a currently no planes to my knowledge that have back up landing gear. In my mind calling the landing gear "main" is redundant. Why is this done?
Quite right there. As opposed to a tailwheel on the non-conventional "conventional" landing gear.
Mains are the load carriers. Nosewheel or tailwheel are for steering and because engineers learned in geometry 101 "any three points form a plane" without them an airplane would tip over. They carry a very small portion of the total load on the ground.
Happiness is not seeing another trite Ste. Maarten photo all week long.
As others have already stated, the 'main landing gear' term is to denote the main set of gear that supports the majority of the aircraft's weight, is designed for the hardest impact of the landing, and is the first set of gear to touch the ground during landing. All other gear is misc. to the main landing gear, though equally important. But, the main gear supports the real forces of the aircraft functions on the ground.