Car: Hoonigan 1979 Hoonigan ‘Loki’ K5 Blazer
Tune: "Airport Jump" by Maka91
Settings: Stability Control - Off
The Gold Mine and Shipwreck jumps are pretty simple, but it's important to practice good habits right away. Approach with good grip, light turns and minimize the bumps in the road to maintain a high speed. Tweak the takeoff angle to see what works best as well. These should be easily grabbed with the above tune.
The Airport Danger sign is a lot more difficult and requires some extra precision, but the above tune should be able to generate at least 7-8 feet of extra distance than what is required. Get a good run up, follow the road, maintain grip, minimize the large bumps in the road, cut through the trees, and shoot left off the ramp. If done correctly, you should be able to grab it, but it might take some practice. The entire run up from start to finish is recorded in 1 take in the video, and I've used this tune to grab this achievement 4 times now so it does work. You'll also grab a little bit of extra distance if the front wheels of your car touch the ground before the back wheels!
Other tips: If you're very close to the goal, don't be afraid to use the rewind feature and slightly tweak your approach for some extra distance. Also, you can take down trees and shrubs and then use fast travel and they will stay down. Use this to clear the path for yourself as well!
Note: The units in the video display km/h and meters.