To complete this mission Viper 1, 2, and 3, and GUNs Mu, Rho and Tau need to be killed. There are 3 GUNs in each group. On starting this mission assign the three CRVs to memory, that way they are easy to find during the battle. Send your wingmen after the first CRV (the nearest), they will launch Torpedoes at it and normally get it's sheilds down. You can then fire two more torpedoes into it to finish it off. The GUNs will be coming after you now so tell your Wingmen to go after the second CRV and engage the GUNs yourself. As all nine GUNs are present at once there is not much point in disabling them. Use a ELS setting of 100/75 and switch to dual fire lasers to take them out one at a time. Do not use your torpedoes on the GUNs. After you have destroyed them head for the second CRV and kill that if your Wingmen are not able to (assign Top Ace Wingmen at the start if you can). Fire your last six torpedoes into the second CRV. This will kill it. If the shields are already down just use 2 torpedoes as that will be enough. Then use whatever you have left on the third CRV and finish it off with lasers. You will have to make sure that you keep your shields charged and balanced as the GUNs fire a lot of missiles at you. Fortunatly the Y-Wing has excellent shields and can stand a couple of hits. Then if you feel like it go after the STD, this will bring on another group of GUNs, but it is not needed to complete the mission.