Airborn battle platform, it carries laser turrets, large missiles, and often it's compliment of Zudjari soldiers. If you can attack it quickly, you may be able to destroy before the soldiers jump out (though you won't get the XP for them).
Related salvage report
Salvage Report: Gunship
The gunship we faced was only one of a countless number of the Outsiders’ multi-purpose assault ships, but it has provided us with an excellent array of technological materials for study. The combined thrust/gravitic propulsion systems, elerium-transfer power source, and assorted environmental control systems should be especially useful if we are to take the fight to the enemy.
More generally, we find that while the enemy gunships are very sturdily built for war, they also bear evidence of extended heavy usage with only minimal repairs. In some cases, unnecessary systems (luxury and entertainment suites) have been cannibalized for use in more pressing repairs (weapons and propulsion), suggesting that the Outsiders have been running low on supplies in the course of their extended conquests. This may explain the urgency of their attack on Earth.