Platform or Boom Caught Overhead or Boom Movement
Prevented by Boom Control System

Lowering the boom onto an object or structure may cause the boom control system
to prevent movement of the machine. This can include movement necessary to lift
the boom off the object. Additionally, if the platform or boom becomes jammed or
snagged in overhead structures, movement of the boom can be regained by doing
the following:

1. Shutoff the machine.
2. Rescue all people in the platform before freeing the machine. Personnel must
   be out of the platform before operating any controls on the machine.
3. Use cranes, forklifts, or other equipment to stabilize motion of the machine to
   prevent a tip over as required.
4. From the ground controls, use the Auxiliary Power System to carefully free the
   platform or boom from the object.
5. Onceclear, restart the machine and return the platform to a safe position.
6. Inspect the machine for damage. If the machine is damaged or does not
   operate properly, turn off the machine immediately. Report the problem to the
   proper maintenance personnel. Do not operate the machine until it is declared
   safe for operation.

Auxiliary power function for emergency lowering

Auxiliary power — normal emergency recovery

Start/Auxiliary Power switch is on the ground-control station. The auxiliary pump can provide hydraulic flow when the main engine/pump cannot operate. JLG states that it can operate functions including main boom lift, main telescope, swing, jib functions and platform rotation.

The basic sequence is:

1. Go to the ground controls.
2. Pull out the Power/Emergency Stop.
3. Select GROUND with the Platform/Ground selector.
4. Do NOT start the engine if you are using auxiliary power
5. Hold the Auxiliary Power switch DOWN.
6. Operate the required boom function.
7. Only operate one function at a time when using auxiliary power.
8. Lower/retract the boom to a safe position.

JLG specifically warns that auxiliary-power functions operate more slowly and that operating more than one function simultaneously can overload the auxiliary pump.