A MD11 crew detected a vapor after takeoff and declared an emergency return to the departure airport where a chaffed oil line was found to have leaked oil which was then carried to an air conditioning pack.

Narrative

After starting #3 engine; noticed a foul odor coming from eyeball vents in cockpit. Started other two engines and taxied from ramp. Odor seemed to dissipate while taxiing out; smell was not irritating to eyes or lungs. Taxied to 22L and had normal takeoff. While climbing through about 12;000 FT-13;000 FT jumpseater came forward and told us that there was vapor/smoke; fumes in courier area. I was flying pilot; we engaged the autopilot and I donned my O2 mask. Captain went rear to investigate; then returned to cockpit and donned his O2 mask. Jumpseaters now occupied cockpit and donned O2 masks. At this point I did notice a vapor in the cockpit. We declared an emergency with Center and requested to return to the departure airport immediately. They gave us vectors back to the airport. While Captain was running 'Cabin Smoke' Checklist I was flying aircraft to an ILS approach. We fully configured the aircraft for landing with flaps 50 degrees. Landing was uneventful and we taxied clear of the runway at Taxiway Tango to the south of the runway. We were met by Airport Rescue and Fire Fighters (ARFF); and I established communications with them. I informed them that there were no fire or smoke indications/warnings and that no engines were shut down. At this point; it appeared that the vapor/fumes were dissipating from the cockpit. However; we remained on O2 until reaching the ramp and our parking spot. We started the APU on taxi in; and secured the engines once in the parking spot. Ran 'Shutdown/Secure' checklists and exited the aircraft. In hindsight; we probably should have just shut down the #3 engine right after it was started; due to the odd smell. However; due to many years of flying during the winter time and occasionally encountering that smell due to deicing fluid ingestion in the engines and packs when starting engines; we chose to remain on the engine start procedure and finished so that we could taxi out. Since the aircraft packs turn off for takeoff; we did not have any indication of vapors or fumes inside the aircraft until the packs turned back on after takeoff. Seeing how light the aircraft weighed; we climbed in altitude very quickly; and we had probably only been airborne about 3-4 minutes when the jumpseater came forward to inform us of the presence of vapors and fumes in the cabin. One thing the Captain mentioned was that due to the vapors and the lighting in the cockpit; it was difficult to see the verbiage on the blue pages of the QRH for the GE engined aircraft.