Date: 201303
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: B737-300
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Aircraft component: Fire/Overheat Warning
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Human factors: Time Pressure; Training / Qualification; Troubleshooting; Workload; Human-Machine Interface
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Other Takeoff Roll
Result: Flight Crew Became Reoriented; Flight Crew Took Evasive Action; Flight Crew Rejected Takeoff; Flight Crew FLC complied w / Automation / Advisory
Contributing factors: Aircraft; Company Policy; Procedure
Primary problem: Aircraft

Narrative: I was pilot not flying on flight. It was the first flight of the day on day four. All preflight checks were accomplished with no anomalies found. We pushed back two minutes late and taxied to Runway 8R. We were cleared for takeoff and the Captain pushed the thrust levers up and called; 'Set takeoff thrust.' By the time I got the levers adjusted and said; 'Set;' I called '90 KTS.' At approximately 115 KTS; the Fire Warning Light on the glareshield illuminated and the associated bell sounded. I immediately said; 'Fire Warning.' The warnings went away almost as soon as they appeared; but came on again; and I repeated 'Fire Warning.' At about 130 KTS (V1; VR 144; 145); the Captain pulled the thrust levers to idle. I called; 'Speedbrakes; Thrust Reversers;' to remind him to follow those steps. I also called; 'Autobrake Disarm.' While decelerating; I told the Tower; 'Company Flight Number; rejecting the takeoff.' We exited the runway and stopped the aircraft in the adjacent run-up area. The Captain made a cabin PA to stay seated. The Tower asked us whether we needed assistance and the Captain told them to send the fire trucks as a precaution; even though the fire warning had ceased prior to exiting the runway. As the Captain was holding the brakes; I reviewed the rejected takeoff procedure in the Non-Normal Maneuvers section of the QRH. I looked at the fire section; but there was no indication of which system may have caused the alarm. The Captain tested the Engine/APU fire system and found it to be operating normally; but when he pushed the Master Caution/Fire Warning reset buttons on his side; they caused the alarm bell to sound and only the glareshield Fire Warning Lights (both sides) to illuminate. We immediately had the suspicion that the warnings we had received on the runway were false (this was reconfirmed at least two more times in the same manner). While the fire trucks were inspecting the aircraft; I ran the Brake Cooling page of the performance computer and determined we needed 53 minutes of brake cooling before returning to the gate. The Fire Chief said there was no smoke or indication of a fire on any part of the aircraft; including the wheels. The Captain communicated the situation with Dispatch and Maintenance Control and determined returning to the gate was the best course of action. In the time between all the preceding events; the Captain briefed the flight attendants on the situation and made another PA to the passengers. We started the APU and shut both engines down to wait out the brake cooling time. The fire trucks waited with us. Sometime during this wait; the Captain got a call from Scheduling about a reassignment for both of us. As we were about to taxi back to the gate; the 'A' Flight Attendant called to request medical assistance for a passenger who said she was feeling pain in her leg. The Captain requested from Operations that paramedics meet us at the gate upon our arrival. We taxied back to gate and blocked in. The mechanics who met us were able to reproduce the false fire warnings.I do not think there is much that could have prevented the rejected takeoff nor do I think there is much more we could have done to handle the situation any better. The Captain and I followed Company procedures and guidance on the aborted takeoff; and were supported by the flight attendants; ATC; fire trucks; Operations; Dispatch and Maintenance. They all performed their jobs well. The only thing is Scheduling might have waited until we were blocked back into the gate before attempting to contact us. While waiting for brake cooling in the runup area after a high speed rejected takeoff; the Captain received a call from Scheduling advising us of a reschedule once we arrived back at the gate. I was aware that we would be continuing to our next destination as scheduled; then (not as originally scheduled) operating two additional legs and then deadheading. Our release time was well past our original release time;but I thought nothing of it; since it was within Scheduling's rights to reassign us. However; upon arriving in our destination; I noticed that the day had a block time of over eight hours; and this was from a print out taken once we had blocked back in from our gate return. I didn't notice it then because the aircraft we were taking over had just pulled into its gate and I was about to perform my preflight duties; and; because I thought that; unless an assignment shows up in red in the [Scheduling Program]; it is legal. However; upon investigating the matter with Scheduling after landing in our final destination; I realized that at the time the reassignment was given; it may have appeared to the Scheduler that it was a legal reassignment (under 8 block hours). However; he/she did not take into account that we were still operating the aircraft and had not blocked back into the gate (still had 30 left to block in). Since I did not personally speak to any Scheduler at the time of reassignment; I do not know the exact words spoken; but I am almost certain that he/she did not ask the Captain what our block-in time was.I would suggest: First; no calls from Scheduling to flight crews while the aircraft is not blocked in (although I realize Scheduling may not have known we weren't blocked back in). Second; have Scheduling always ask; 'What's your block-in time?' Lastly; as pilots [we should] not answer our cell phones while not blocked back into the gate after a gate return event.


Second narrative: At first we were unable to contact Operations. Thinking we may be in a bad spot for the radios; I asked Dispatch to have them call us and turned on my phone. Operations said when we came back we would go to a different gate and another aircraft was due in about 15 minutes later for us. We let Tower and the Fire Chief know we were starting an engine and heading back to the gate and the fire trucks said they would follow us to the gate. Somewhere in here I got a call with and it was Scheduling about a reassignment for both of us. I was also notified by the 'A' Flight Attendant to request medical assistance for a passenger who said she was feeling pain in her leg (she had a full leg cast/brace and apparently hit the bulk head with her leg during the abort). I immediately requested paramedics from Operations.I think everything went very well and everyone did a great job; especially First Officer; he did a fantastic job! I was a little disappointed with myself thinking maybe I could have done things better or faster. Normally a pilot not flying guy; this self-inflicted AM was very early; a fire warning on takeoff was a bit of a surprise. I was so impressed with myself for letting the rejected takeoff (RTO) function work without me overriding with manual brakes and how well the RTO worked. I felt I could have been faster with the speedbrake and reversers; but the First Officer did great making his callouts. It was a bit disconcerting having the Fire Warning lights and bell on the glareshield without any other indications; it makes you think you might be missing something. The First Officer did a great job quickly reviewing the fire section of the QRH; but we were still scratching our heads until I was able to duplicate the warnings by hitting the light/button assembly. Ironically; I have been studying and reviewing all the pilot and Safety reports lately for an upcoming PT; like the one on RTOs. I still wasn't in the you can't takeoff mode like I am in the simulator and need to mentally prepare that way every takeoff as recent reports discussed.Not really sure but we may have been assigned to work more than an 8-hour day; but without the 'snapshot' right at the time of the reassignment; I can't be sure. After a RTO event and near the end of our brake cooling period; I received a call from Scheduling that the First Officer and I were being reassigned when we arrived in our next destination. Between the RTO; all the coordination with Dispatch; Operations; the flight attendants; Fire Chief; ATC; checklists; logbooks write-ups; medical situation with passenger; and talking to Maintenance; I accepted the reassignment without looking at it thinking I would have a chance to review it.My phone would have never been on had we not had communication problems with Operations. It was also weird that all calls I have received from Scheduling always showed 'unknown' and this one came up with XXX area code. With all the coordinating with Dispatch and Maintenance not sure who I expected to call me while holding brakes during brake cooling. Looking back on it; it wouldn't have taken long for me to actually review the reassignment rather just accepting it.


Synopsis: A B737-300 crew rejected a takeoff for a fire warning which turnout to be faulty fire handle switch but continued the day's flights on another aircraft with a rescheduled flight sequence. Later that day they realized 8 flight hours had been exceeded.