I won't address the laws that could kill a party plane (some are security, most are regarding passenger safety, and others were too difficult to simplify and stuff it in this post) as the idea itself it already an accident waiting to happen. Party buses don't go fast and usually go on streets near a popular social area of a city, usually at 30 MPH at its fastest. As such, people can dance, drink, and be served cocktails in comfort while being transported slowly around town. With an aircraft, it is a completely different (and messy scenario). Supposing there is a party plane and it isn't a turbo-jet (making it too expensive to fly party-goers around and needlessly fast to be rushing around the elements with, what is essentially, a nightclub inside) and it isn't located at an international or busy airport (or else the passengers have to get through the airport with the security line at any other airport, and safety officials won't be happy having drunkards stumbling around their terminals and a party plane flying around large intercontinental airliners).
So you have your turboprop or piston aircraft picking up party goers at a small airstrip and you get everyone to the air. All is nice and fun until you hit turbulence and/or clouds. Then all of the drinks being served, the employees, and partygoers will be shaken around inside like the beans inside of maracas.
|Except the beans in the party plane are squishier and tend to eject their liquids while squished or by the nausea from the shaking|
Now, a party blimp might be functional, but not cost effective and the last thing you want is a partygoer getting sick up there with nowhere to go but down and fast. And it isn't like the blimp is going to be climbing up and down routinely like a ferris wheel. And if winds aloft hit this aircraft, things will get messy as well.
|Like your drink, you get shaken and stirred.|