Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Air Traffic Control Provided Assistance; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; Flight Crew Requested ATC Assistance / Clarification
Aircraft
During climb out we received a level 1 alert indicating the Manifold Drain valve was open. Utilizing the QRH we verified the switch was actually not in the open position; verified the light bulb was operable; and the QRH consequence of not utilizing the cross-feed manifold as the fuel would drain if it were open. This was followed by another alert Tank 2 LOW with an indication of ZERO fuel on the synoptic display. Engine 2 continued to operate. The tank lo alert disappeared; we cycled to manual and back to automatic on the Fuel Controller and the Manifold Drain alert disappeared. Almost immediately later at the top of climb the above two alerts re-appeared with zero again in tank 2 but with 600 LBS and 1200 LBS of fuel in tank 1 & 3 respectively without tank 1 & 3 low alerts. The Fuel Quantity/Used Check along with a WHITE 'possible fuel leak' alert displayed on the Fuel synoptic. Captain requested and executed an immediate turn-back and when queried if it was a mayday event replied yes. We received excellent ATC support and flew directly back to the airport. The procedures for preparing to return went exceptionally smooth after the event. We approached high and fast just in case and had time to re-verify our fuel; discuss airspeeds and take pictures of the status on the synoptic displays. At the FAF; we were stable and in the groove followed by an uneventful landing. The fuel system went back to normal and the 32;000 LBS of actual fuel on board was on display. The fuel system was giving erroneous indications first with a manifold drain valve alert suggesting the drain valve was open and to not utilize cross-feed. We verified the alert was questionable by observing that the Manifold Drain switch did not indicate open and the bulb was verified operable. The second alert indicated Tank number 2 fuel was low and the indication was ZERO 0! Engine two continued to operate without cross-feed so again we verified the alert was probably erroneous. The follow on alerts were an escalation of more suspected indications but were treated as possibly actual as there is no way of knowing with certainty that they were erroneous.
Received diversion report from [this] flight as it approached top of climb. ACARs sent to crew; they confirmed returning to [the airport] due to fuel quantity issue. Aircraft landed safely; after which Captain called on to advise they had received multiple fuel quantity; fuel low and fuel manifold alerts and were unable to determine exactly how much fuel was on aircraft. Crew [informed of the mayday event] on the return; no fuel was dumped. [Supervisor] notified manager on duty (no airport manager present) and I notified duty officer and submitted shift note as per procedure. At time of [this report]; aircraft is still down in at the airport and next leg will likely cancel.
An MD-11 flight crew reported erroneous indications from the fuel systems during climb; resulting in a return to the departure airport.