Date: 201212
Local time of day: 1801-2400
Location: ZZZ.ARTCC, US
Flight conditions: Mixed
Weather elements / visibility: Rain
Light: Night
Aircraft: MD-11
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Air Conditioning and Pressurization Pack
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Hazardous Material Violation; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight; Pre-flight
Result: Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Contributing factors: Aircraft; Weather
Primary problem: Aircraft

Narrative: We had a 2 hour delay initially due to ATC and weather. When arriving at A/C; I closed cargo door since it was raining and loading was complete. Shortly after I did; the Cabin Smoke Level 3 alert went off in cockpit. Captain tried to call Maintenance on radio; he was unable to use radios and there were multiple failures/messages and screens flashing in and out with X's on them. I informed tug driver; (he was the only one around the airplane); and Captain called Maintenance on his cell phone. After numerous maintenance personnel showed up; the Captain and I went inside to allow for them to work on the maintenance issues. Soon after we were asked to come back out to A/C to enter discrepancies in logbook. When we returned Maintenance was still working on aircraft. One of the mechanics referenced an odor and stated it was from a possible pack overheat. They left the cockpit and allowed us to start our preflight while they worked on the logbook. The Captain requested a visual inspection of the area and nearby cans where the smoke detector went off. The loaders started to unload cans so the inspection could take place. While this was taking place; we gained knowledge that the A/C had 2;200 lbs of dry ice; however there was not a dry ice notification on A/C.  Takeoff was max thrust due to wet runway. Initial climb out was routine; we did put anti-ice on during climb. Later in climb we received a Pack 3 OFF alert; followed by a bleed 3 off message. While retrieving checklist for Pack 3 off; message and alert went away as problem corrected itself. Shortly after; we received a Level 2 Fuel Quantity Fault alert with master caution. We ran the checklist for this issue; and I selected fuel to manual per the checklist. It was while running this checklist I asked the Captain if he thought the odor from the possible pack overheat on ground that Maintenance mentioned was getting better or worse. After completing the Fuel Qty Fault checklist; I informed the captain that the inside of my nose was starting to get irritated. I had not had this happen before; and I believed the odor could have been the cause; however was not certain. I told the Captain I thought I should go on oxygen to see if it made a difference; and he agreed and said he would also. After donning the oxygen mask; the captain and I discussed our options and assessed the situation. We decided the best course of action was to make a precautionary return. The captain exercised his authority and informed the company of our return via ACARS; while I informed ATC and asked for vectors to return. The Sensor Fail and Fuel Qty Fault alert with master caution continued to appear on and off after completing checklist and during our return. There was no indication of smoke or fire at any time. The decision to return was precautionary.  Factors considered and discussed when making the decision to return were: weather; familiarity; the fact that is was a non emergency situation; maintenance; fuel; etc.  After landing we were informed Dispatch had declared an emergency for our flight. After we returned inside and discussed with the ACP on duty; the Captain was asked to call Crew Scheduling. It was their intent to send us out in a different aircraft. The Captain informed them he didn't think that was a good idea and they decided to send a different crew. I did not think it was a good idea after the event to continue our duty day and was glad the Captain stated his concern; it would have led to a very fatiguing night.   On a side note; I want to express how much I appreciated the new oxygen masks. When coordinating the return; talking on the radio; and preparing for approach; it was apparent how less cumbersome it was with our new equipment. Thank you and KUDOS to all who were involved in making this change! Had this been a true emergency; there is no doubt in my mind the new O2 masks would have been a very beneficial asset that would greatly increase the ability to successfully workthrough any emergency requiring oxygen and smoke goggles.




Synopsis: MD11 First Officer reports a Cabin Smoke Level 3 alert during preflight shortly after closing the cargo door due to rain. It is discovered that there is 2;200 pounds of dry ice aboard without the proper paper work but eventually all is sorted out; signed off by Maintenance and the flight departs. Passing FL360 a Pack 3 OFF alert is noted; followed by a bleed 3 off message. Before any steps can be taken the problem self corrects followed shortly by a Level 2 Fuel Quantity Fault alert with master caution. This issue is dealt with then the pack odor returns and the crew elects to return to the departure airport.