Good point about the hovering, and running out of fuel, if you played a "Fast" zombie game, with fast infections, maybe somebody on board would turn and attack the crew...?
Each turn a roll of a double 1 on 2d6, that would force the helio not to hang around to much.
I`m looking forward to 28 weeks later, its out in the Uk 11th may
I guess for my zombie rules the trait would be
fast infection
When killed by a zombie, roll a d6, on a 3+ instead of staying dead, the bits infect you and you are now a zombie
Again any transpot units used to move troops around the battlefield, a 2d6 needed a double 1 for a infection killing the crew, only rolled when troops enter the transport
Off to watch some Tv, hope that got your mind working overtime..!!