Lyric discussion by Jivin 

Cover art for Jet Pilot lyrics by System of a Down

this is going to sound really simple and retarded but... maybe its talking about how transportation has evolved... how a horse used to be a popular medium of travel (and a horse cant ride through a bay (dont get techincal :P)) and now we have jets...

and maybe the singer is a passenger, saying 'my horse is a shackled old man' referring to the pilot.

thanks for not laughing :)