Date: 201307
Local time of day: 1801-2400
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: MD-83
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Cargo Compartment Fire/Overheat Warning
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Time Pressure; Workload
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew FLC complied w / Automation / Advisory; General Declared Emergency; General Maintenance Action
Contributing factors: Aircraft; Company Policy
Primary problem: Aircraft

Narrative: Immediately prior to the incident; we had been in cruise flight at FL330 for over an hour; and in radio contact with the ARTCC. The flight was completely uneventful; until the 'Master Caution'; Mid Cargo 'Loop B' Det; and 'SMK DET LOOP' lights all illuminated. This was soon followed by the autopilot disengaging; however; we were able to re-arm it immediately. We referenced the QRH Checklist; read through it a few times (as it is somewhat difficult to follow); and performed the test/check a few times for verification purposes. We also read through the actual Cargo Fire Checklist; to compare and become familiar. We determined that it was a failed loop per the checklist and proceeded to contact Operations. We relayed the situation to Dispatch and Maintenance Control; and referred them to QRH. We talked through the procedure with them; and they agreed that it was a failed loop and we were to continue the flight to the filed destination. Very shortly after the call ended; we heard the cargo fire aural warning; and noticed the 'Master Warning'; 'Cargo Fire'; and cargo 'Fire' LED lights were all illuminated. This time; both the autopilot and autothrottles disengaged. We immediately declared an emergency with ATC; and asked them for descent and vectors to the nearest airport; and began the Cargo Fire QRH procedure. ATC offered a nearby airport; with the longer runway being 6;600 FT. We agreed that would work and were given an easterly heading and descent. After completing the checklist; the First Officer called the cabin crew to inform them of the situation; that we were making an emergency landing; please prepare to land in about 10 minutes and we would get back to them soon. As we continued descending; we were handed off to ARTCC who relayed the weather and runway information and gave us final vectors to the airport. The First Officer made another call to the cabin crew to let them know the plan for evacuation; and to be sure to evacuate out the left side and tailcone only and not to use the over wing exits or go out the right side (due to the cargo compartments being there and wanting to keep all the passengers together). We overflew the airport to continue descending and turned left to join final for Runway XX. When landing assured; and prepared with the Evacuation Checklist and plan in place; we decided to fire the second bottle as a precaution (prior to the 15 minute auto fire). The First Officer then made one final call to the cabin crew to verify they were ready and prepared to evacuate. ATC asked us about cancellation of our flight plan with them or on the ground; to which we said on the ground. We were given the Tower frequency; but upon contacting them we realized there was no one there and it was now a CTAF frequency and made transmissions there. On short final we were able to see a rescue vehicle off in the distance; and that alleviated some of our immediate concerns. We landed abruptly on the centerline and immediately began stopping the aircraft with the use of autobrakes and reverse. We stopped on the runway and immediately began to execute the Evacuation Checklist. Upon command; the cabin crew; with the help of their ABPs; initiated the evacuation using the L1; L2; and tailcone slides. I called Dispatch as soon as possible after landing; to advise them of our situation and that we were all okay. After a very quick evacuation; we told the cabin crew to go down the slides; and we tossed them some EMKs. We instructed them to gather the passengers together in the middle of the field; as many of them were spread out and wandering. This field was in between two crossing runways; and we heard other aircraft on the ATC frequency planning to land. Our primary concern at that point was keeping the passengers together and away from the other runway. I went up and down the aisle screaming; 'Is anyone here??' and checking to make sure no one was still on the aircraft. I sent the First Officer down the slide; and then Ifollowed. The First Officer and I walked around the aircraft screaming for anyone who might be lost; hurt or left behind; and also looking for any potential safety hazards. Finding nothing; I then told the First Officer to go with the passengers and make sure no one was hurt and that I would help the Fire Department as they began to approach the aircraft. I assisted them in locating the cargo bins and instructed them on how to open the doors. The First Officer and I did our best to assist between the passengers; emergency response; and field many calls with Dispatch; Maintenance Control; Crew Services; the Chief Pilot and the VP of Flight Operations. We later assisted Airport Ops in getting all the passengers to an area close to the runway for transport back to the terminal. After the Fire Department cleared the aircraft; and per instructions from Maintenance Control and the Chief Pilot; the First Officer and I reentered the aircraft via a ladder; again inspected the inside; and then secured the aircraft. Local Maintenance arrived and removed the tailcone; deflated the slides and stuffed them back inside the aircraft. We arranged with them for a GPU since the emergency power had been on; and we knew this aircraft had a recent history of APU discrepancies. Per the VP of Flight Ops; we then started the aircraft and taxied to the cargo ramp; under escort from the Fire Department. After we were safely parked; we asked the Fire Department if they could sweep our route and the runway to check for any luggage or debris; to which they found none. We were informed by Operations that a ground crew would be coming on to unload all the checked and carry on luggage and that the passengers would be transported by bus to our destination. We filled out the logbook with the assistance of Maintenance Control and then were released to the hotel for the evening. I have several suggestions 1. A better direct communications method would be a valuable resource that an airline of our size and scope should not be without. In the time it would have taken to try and reestablish a call; we could have sent a few quick messages letting Operations know what was happening and what our intent was; and get some valuable information from them. Given the limitations of carrier's route network and schedule; it can be challenging at times to effectively communicate with the company. 2. GLOW STICKS--A great idea from one of our cabin crew. Being out in a field; in the middle of the night; with weeds 4 feet tall; it would have made it easier for both the passengers and crew members to easily spot and identify who were crew members if we had glow sticks. We; as a crew; decided keeping glow sticks onboard the aircraft would be a great tool to have. 3. SINGLE POINT OF CONTACT--We talked on the phone to so many different people during the course of this evening; it got to be a bit overwhelming; especially while simultaneously dealing with the people on our end. Some of the departments in Operations did not seem as though they were in the loop; or where unaware of something spoken about with another department. We should have a single contact point; such as a Duty Manager or ATC Liaison to which all irregular operations calls are filtered through. Communication would be greatly enhanced and simplified if both sides had one 'go-to' person. 4. QRH SIMPLIFICATION--Some of the QRH procedures have been identified as difficult to navigate through; ordered in a less than ideal manner; or not easily guiding the user to the next/appropriate checklist if needed. I feel that a checklist having to do with a potential fire warning should be much simpler; and more direct. 5. MAINTENANCE- the aircraft involved had not flown in a few days due to a variety of maintenance discrepancies [from] the previous flight. Some of the discrepancies; which were 'cleared'; were noticed (some almost immediately) throughout our trip. In the interest of timeliness; many discrepancies are immediately deferred or commented 'Ops check good' rather than taking a few minutes to determine what might be causing the problem.




Synopsis: A MD-80 crew declared an emergency and diverted after a second cargo fire warning sounded along with secondary indications and then evacuated on the runway but no fire or smoke was detected by the Fire Department.