If the person provides a personal service, bags, serve food/drinks, clean up your mess; in the US, they get a tip. It’s a societal norm, but that varies around the world. In Russia, hand the ground crew a carton of Marlboros and they’ll move mountains to move things along. By the way, yes I tipped the fueler, the lab service guy and the driver. Expensed it, too. To Insure Promptness, works

At EAL, we had a captain who would gather up the cash for dinner from the crew, pay on his credit card bill and add a meager tip. Any place with slow service was remarked by, BOS Captain Frank was here”. Which was very true in PDX, where nary a waiter was was seen until the owner came out and said, “ask Captain Frank why you’re not welcome here”. Tipping is social lubricant.

GF