Cato Novus

In the first part of Mission 13, where you have 6 objectives, of which you need to succeed at 4, you need to obtain a rank of at least two S and two A; although at least 3 S ranks would be better. I recommend the CFA Nosferatu, loaded up with the ADMM Special Weapon, which is amazing against both Air and Ground targets.

The two Objectives you should clear first and foremost are the Steel Gunners Airfield Recapture(Objective A) and the Marigold Naval Assault(Objective D). The Nosferatu's ADMM makes assisting the Marigold too easy, even at Expert Difficulty(I dunno about Ace, I flew a F-15E Strike Eagle that time). It lets you destroy the Estokvakian ships two or three, sometimes even four, at a time. As for the Airfield Recapture, you don't get as many Objective Targets clustered together at once, but you can still clear a path for the Emmerian ground forces quickly and cleanly.

After those two objectives, I'd suggest the two Anti-Air Objectives to clear up the sky, Objectives E and F where you assist Windhover and Avalanche to take down the Estovakian Radar Jammers and their ESM craft. It may help to land at the airfield and swap out your ADMM for the EML, because some of those Radar Jammer craft are very heavily armored, and will take one hell of a beating before they fall.

Once those are all down, whether you did or didn't change out your SP, land at the airfield to either switch back to the ADMM, or at the very least, reload it. You will need it for the fight with Pasternak.

The reason people have trouble with getting an S on this second half of the mission is because they think they're supposed to kill Pasternak fast. This is not true. While speed does help, you actually have to destroy not only Pasternak, but at least 30 of the drones flying around with him. This is why you need the Nosferatu's ADMM, it can take many down at once, 12(one for each warhead in a single firing) each time, if you're lucky. I for one still say that the drones in this game are ridiculous, but oh well.

Now, if you managed S on the second half, and your average for the first four missions an S rank, you should come out of this with the highly sought Mission 13 overall S rank.

Fly fast and shoot straight.