Date: 201501
Local time of day: 0001-0600
Location: ZZZZ.ARTCC, FO
Flight conditions: IMC
Weather elements / visibility: Turbulence
Aircraft: MD-11
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
ATC / advisory: Center ZZZZ
Aircraft component: Pneumatic Ducting
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Captain; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Maintenance Action; General Declared Emergency
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: 25 minutes into flight a level 1 AIR SYS 2 OFF (Air System 2) came up. As I was pulling out the QRH a level 3 AIR MANF 2 (air manifold 2 fail) FAIL came up. The air system protected itself and did the automatic decay check. We followed QRH procedures which requires us to LAND AT NEAREST SUITABLE AIRPORT. I sent a message to Dispatch with our emergency and said that we were going to return to the departure airport. We started to slow up and declared an emergency with ATC and requested to return. They put us on a vector and gave us new routing instructions. We also needed to dump 27K of fuel to land below max landing weight. ATC gave us approval to start dumping fuel as we were descending from FL255 to FL170. We request one turn in holding to complete the dump and to finish checklist. I briefed a CAT 1 auto land. After one turn in holding we were cleared inbound to an uneventful landing. The AC system operated as designed when the jet pump hose broke and was sending hot air into the AC. It was due to the failure of a part which is not readily accessible to inspect.


Second narrative: Had an inflight emergency (air manifold 2 fail) which required a return and dumping of approximately 27K of fuel. After an uneventful return I wrote up the air malfunction and failed to write up the fuel dump in the Logbook. Once we blocked in there were numerous mechanics and other personnel on board due to us declaring an emergency. In addition; the ramp was pushing us to go to another plane to start the preflight since they were going to trans load the freight. Not until we took off in the new plane I was reading the FOM on reports and realized I should have written up the fuel dump. I ACARS Maintenance Control and asked them to notify ramp maintenance to write up the fuel dump of 27K in the Logbook. I also made a SATcom call to Dispatch to minimize any misunderstanding.Allowing the numerous personnel onboard the AC during post flight to distract me from completed a proper post flight. Slow down and read over procedures that we do not do every day. I allowed all the personnel on the plane after we landed to distract me from completing a proper post flight.


Synopsis: MD11 flight crew receives a Level 1 alert AIR SYS 2 OFF followed by a Level 3 alert AIR MANF 2 FAIL shortly after level off in cruise. An emergency is declared; fuel is dumped and the flight returns to the departure airport.