Setup: Iron Mule is a mission in Grand Theft Auto Online as part of the Agents of Sabotage update. It is part of the Oscar Guzman Flies Again mission strand.
Description[]
After accepting the mission, Oscar Guzman will provide the player with Dune Buggies and signal jammers. Oscar will send the location of a weapon testing site set up by Eberhard Munitions at the Redwood Lights Track.
The mission is to plant signal jammers in the area, force Eberhard to send reinforcements in their DH-7 Iron Mules, jam their flight systems and steal the vehicles to be used to carry Titan 250 D ammunition crates.
Arriving at the weapon testing site, the player must plant the jammers at four strategic locations. After the jammers are planted, the player must destroy as many of Eberhard's assets as they can find in the area (fuel tanks, vehicles, crates, etc.) in order to make Eberhard call in their DH-7 Iron Mule air support.
Once the four DH-7 Iron Mules arrive with reinforcements, the player must activate the jammers they have just planted. This will cause the helicopters to lose control of their flight system and be forced to land, allowing the player to steal one of them.
After stealing the first DH-7 Iron Mule, the player must deliver it to McKenzie Field to be stored by Oscar. The first DH-7 Iron Mule will be used to steal the Titan 250 D ammunition in the next setup, and will be used by Oscar during The Titan Job to transport the ammunition to the Titan once it is finally stolen.

Optionally, the player can steal one to three additional DH-7 Iron Mules (to be used to steal additional cargo in the next setup) and an Insurgent Pick-Up Custom from the Redwood Lights Track.