Three choices on explosive usage for the airship group: 

1. Blow up zombie Tennant
2. Blow up Sload's barrier 
3. Destabilize the airship balloon.

Success on option 1 bypasses zombie fight. Success on 2 weakens both Sload and zombie. Success on 3 have a chance of ending the encounter, but also have the chance for casualties; more dice rolling is required is 3 is chosen.