Flight Crew Air Transport Pilot (ATP)
Confusion; Human-Machine Interface
Aircraft Equipment Problem Critical
Flight Crew Returned To Gate; General Maintenance Action; General Declared Emergency
Aircraft; Human Factors
When cleared to taxi into position and hold Runway 25R we received a #2 engine fire indication. We complied with the QRH including firing a fire bottle. We also called for CFR as an added precaution. The #2 engine fire system had an MEL for LOOP B INOP and the switch was in the proper position locking out LOOP B per MEL. As a result there was only had one operable loop on that engine. After the bottle was dispensed and the FIRE light extinguished we tested the FIRE DETECTION SYSTEM and it tested OK for all engines with the exception of the locked out loop. CFR scanned the engine with a heat signature device of some sort and confirmed there was no fire. Several minutes later we received a second fire warning on #2. Fire Indications remained on even with maintenance on board at the gate.
A DC-10 flight crew took appropriate QRH actions when they received a fire warning on the number two engine as they taxied into position for takeoff. The warning was ultimately determined to have been false.