The Viper Mk. VII Is a great improvement over the Viper Mk. II, with superior battle capabilities and better flight informatino for the pilot. After the Cylons infiltrated a fatal backdoor in the Command Navigation Program, most Mk. VIIs have been retrofitted, losing part of their performing features. Most of the Mk. VIIs aboard the Galactica were destroyed when the Cylons hacked their navigation software. The surviving ones, retrofitted with older software, are still very effective when flown by skilled pilots such as Apollo.