Grab a Suppressed Rifle at Ammu-Nation and head to the water tower and climb up to the top. Shoot out the guards to cover Ron, as well as the patrol guards that he asks to be taken down. Clear out the lights when Ron asks you to. For the helicopter pilot, hit him through the front glass window of the chopper while it is hovering.
Switch to close-range weapons and move from cover to cover in the hangar. Shoot the enemies on both runway sides first. Next, shoot down the chasing vehicles. Jump out from the wing and ride your plane located at the end of the runway.
Next up, take off and don't forget to raise up the landing gear. While flying, keep following Ron and stay as low as possible to avoid getting detected by radar. Avoid flying over the airbase. After all the obstructions, chase Ron through the valley. The best path is through the bridges and the mountains on the leftside area.
While the airfield is still far off the horizon, line up and lower your gear while descending and cut the throttle near the runway. Finally, reverse once you are landing to avoid getting crashed.
