Date: 201303
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-300
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Fire Protection System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Human factors: Communication Breakdown; Situational Awareness; Time Pressure; Training / Qualification
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: During climb out on the departure; our fire warning bell sounded along with both FIRE WARN lights and the Cargo Bay FWD FIRE light. We immediately declared an emergency; discontinued the climb; and contacted ATC with our request for assistance returning to the field ASAP. I was flying and continued to do so as my First Officer ran the QRH CARGO BAY FIRE Checklist to completion. This checklist resulted in extinguishing all fire indications. Given the short time frame between the first fire indication and landing; I was extremely pleased with the calm and collected professional response from my flight attendants. The emergency procedures prevented me from providing much detail when I spoke to them. It was a relief for me to know I had a great crew in the back. They quickly understood the gravity of the situation and responded in a way that was calming for our passengers. ATC provided the necessary traffic priority for our expeditious visual approach. After finishing up with the QRH; my First Officer promptly computed landing data: Touchdown GWT 124.0; Brakes on Speed 110; Taxi Distance 1.5 mi; 14.7 mil FT-LBS. Fire crews met the aircraft after landing in the #1 holding pad. They used their thermal imaging equipment to quickly determine we had no heat issues in the cargo bay; noted no smoke; etc. We were cleared to continue by the fire crew. We proceeded to a gate where the passengers were quickly removed from the aircraft. After all souls were clear of the aircraft (as per QRH) the forward cargo bay door as uneventfully opened by fire crews. The fire indications were false; no fire evince found. The Maintenance Supervisor was debriefed (logbook entry). A call to Dispatch from the jetway was made to debrief our Dispatcher.Lessons Learned: The firefighting personnel wanted to open the forward cargo bay door immediately after we parked at the gate. Our QRH warns us to wait until all passengers and crew are clear of the aircraft. This procedure (to avoid introducing oxygen into a possible smoldering cargo bay fire) was foreign to the firefighting crew. Perhaps we can do a better job of informing them of our QRH fire procedures.


Second narrative: [Narrative 2 contained no additional information.]


Synopsis: A B737-300 Forward Cargo Fire Bell alerted at 9;000 FT on departure; so an emergency was declared and the flight returned to the departure airport where the flight crew had maintenance and fire crews keep the cargo closed until all passengers were removed.