This achievement is for completing the fourth mission of the game and can be obtained on any difficulty.
This is my playthrough of Mission 04 - Rescue on normal.
Aircraft used: F-15E
Special weapon: 6AAM (6 air to air missiles)
Score required: None
Time limit: 15:00
Take this slowly and don't try to rush - I did and it took a few attempts as a consequence.
I would recommend making use of the map and expanding it to it's largest size using the view button (the old back button). You can then fly between the radar coverage and avoid being detected. I reduced speed through narrow gaps, making fine adjustments with my yaw controls but be aware the wind picks up and will try to knock you off course.
Tip: I played through a couple of hours of multiplayer, gaining enough MRP (in game currency) to purchase the F-15E which made this a lot easier and more fun than the starting F-16C. Around Mission 12, I had enough to purchase the F-22A which is the most capable aircraft I've found so far. The currency, planes and most part upgrade unlocks work across multiplayer / singleplayer but some upgrades are exclusive to multiplayer. You can also go into 'Free Mission' to replay for some extra cash.