Airmail

In this quest you have to shoot a red flare into the sky while being in the center of the old sawmill in the east of Woods. If the flare doesn't reach a certain height, the quest objective won't complete. You can use either the handheld RSP-30 red flare provided by Mechanic via in-game mail or a 26x75mm red flare cartridge which can be bought at Ref LL3, and is fired from a signal pistol. If you use the handheld RSP-30 red flare, make sure to aim it upwards, but not too much or it lands behind you.