Flight Crew Last 90 Days 191; Flight Crew Type 191
Situational Awareness
Aircraft Equipment Problem Critical
Aircraft Aircraft Damaged; Flight Crew Became Reoriented
Human Factors; Procedure
The conditions were clear; it was night and VMC; and the ramp was dry.  After arrival; there was an aircraft at our gate.  This aircraft needed to be towed off the gate and we waited nearly abeam the gate on the taxiway.   After the aircraft departed the gate; we were cleared into the ramp by Tower Control.  The number two engine was shut down in accordance with the FOM.  Upon lining up for the lead in line for the gate; both the Captain and I visually cleared the safety zone; which was clear; and verbally confirmed this with one another in accordance with the FOM prior to entering the zone.  The Marshaller had the proper wands and cleared us in.  After the brake was set; as the jetway pulled up to the aircraft; there began a low rumble and vibration.  Both the Captain and I checked the engine indications and then stated that we thought something might have been ingested into the engine.  The Captain shut the engine down immediately; the whole process took seconds.  The aircraft became dark and the Captain started the APU.  Not being sure of what had happened; I opened the window to ask the Ramp Personnel what was happening; but they had scattered due to debris being thrown forward and rear of the engine.  I gained the attention of a Ramper and asked what had happened and he ran out of view.  The Captain brought the APU online and the lights came up for our Passengers to deplane.  At this point; the Agent appeared on the aircraft and informed us that we had ingested the air conditioning hose into the number one engine.The safety zone was clear and according to the Agent; the hose was not chained down.  I think that we need to have a procedure where the wands that the Ramp uses to marshall us into the safety zone are attached or clamped to that chain that secures the air conditioning hose.  It could be as simple as the wands do not come off that chain until it is secured.  Once the aircraft is stopped and the hose connected to the aircraft; the wands would be clamped to the chain again.  After the APU is started and the hose disconnected from the aircraft the wands would not be removed for the wing walkers until the chain is secured.  After the aircraft is pushed back; the wands again would be secured to the chain and the whole process would begin again for the next aircraft.  You don't touch the wands until the chain is secured.  The Ramp is a busy place.  At night; the lighting is reduced and sometimes the Rampers are moving from one issue to the next.  This is something that needs to be [ingrained] into the Ramp's flow; like checking your configuration before landing.
A B737-700 First Officer reports a ground air conditioning hose being sucked into the number one engine as the the jetway was moved toward the aircraft.