It was mostly in jest. But on a serious note, many of the NG folks work heavy machinery for a living. At least many of the HIANG folks that I know. They work on the bigger planes though.
NG units find the same types of billets (jobs) as the active units. Communications-Computers, satellites, automotive mechanics, aircraft mechanics and loadmasters, pilots, navigators, air traffic controllers, security (SPs), and on and on. They are trained to augment the active forces if they are ever required to deploy with them.
The heavy machinery operators are mostly Army and Navy. The AF does have similar types of skills for forklifts and bulldozers, but for building levies and bridges, the SeaBees and Army Corps of Engineers are loaned out for a lot of that.
I was a Computer-Comms officer (Reservist on active duty -- ROTC grad), but I still had training and a military license for driving up to 2-ton trucks.
