MODIFIED JUMPMASTER DUTIES AND JUMPER ACTIONS24-4. The JM relies on the loadmaster to obtain and relay en route information. Under IMC, the JM still attempts to perform all of the required checks. They may not be able to observe safety hazards beyond the immediate area of the door.24-5. Jumper actions during descent under normal conditions are modified in IMC training. Modifications are made when using the T-11 and MC-6 series parachutes.