At first glance I thought, Oh, a typo for 'checker.'
But with your context, I picture the guys who stand out on the tarmac wearing earmuffs and reflective vests, and toss the pieces of luggage from the luggage wagon (ungently) onto the conveyor belt that goes up into the cargo hold.
You're probably familiar with 'chuck' as a verb meaning to throw or toss casually, so if that seems to fit, I'd go with it. If so, the description is probably more humorous than official. (-:
*f5* As pengu said more concisely, sorry.
to chuck sth. [coll.] – etw.[acc.] schmeißen
to chuck sth. [coll.] – etw.[acc.] werfenDictionary: to chuck