Landing gear Exercise 9

Landing gear usually includes wheels equipped with ______________ for solid ground. 

Sometimes a small tail wheel or skid is added to aircraft with tricycle ______________, in case of tail strikes during take-off.

In retractable gear systems, the compartment where the wheels are stowed are called ______________, which may also diminish valuable cargo or ______________. 

Pilots confirming that their landing gear is down and locked refer to "three green" or "three in the green", a reference to electrical indicator lights from the ______________and the two main ______________. 

Multiple ______________ are usually provided to prevent a single failure from failing the entire landing gear extension process.