Date: 201302
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb; Initial Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown; Distraction; Situational Awareness; Time Pressure; Workload
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant
When detected: In-flight
Result: Flight Crew FLC complied w / Automation / Advisory; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; General Declared Emergency
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: On departure while climbing (hand flying) through 9;000 FT and about to level at 10;000 FT the Lead Flight Attendant called the flight deck. The First Officer asked if he should answer the phone and I said not at this time. At few seconds later ATC cleared us to 14;000 FT. We acknowledged and kept climbing. Before reaching 10;000 FT we then answered the call. The First Officer spoke to Lead Flight Attendant and she reported a strong acrid odor in the cabin. We then asked ATC for a level off to work a problem for a few minutes and then we selected Command A autopilot. Neither the First Officer nor I noticed any odor. I then handed the aircraft to First Officer and spoke with the Lead. I then arranged to have the Flight Attendant enter the flight deck while I investigated the cause. As soon as I opened the cockpit door I noticed how strong the odor was and immediately informed the Lead that we were returning to the departure airport and [to] prepare the cabin for an airport return and that we would be back on the ground in 10 minutes. Upon closing the cockpit door I resumed my duties at pilot flying and informed the First Officer that we will be returning. We contacted ATC and requested to return. After a very brief discussion we declared an emergency and requested Runway 9 for landing. Not sure why the event happened but in my post flight de-brief with the flight attendants I was informed that the aft Flight Attendant smelled a strong odor about 10-20 seconds after takeoff and the odor had worked its way up to the forward flight attendants about a minute after that. Also in my debrief the Lead Flight Attendant said that next time she would use 6 chimes to get my attention. Also in my debrief with the First Officer and flight attendants; and I am embarrassed to say I neglected to use TEST procedure. In the debrief the flight attendants hadn't noticed that I didn't use the TEST procedure until I brought it up. They assumed correctly the situation. I also made a PA to the passengers that we would be returning back to the airport as a precaution and we would be on the ground and at the gate in 10 minutes. However I strongly believe that active communication was the key and TEST should always be performed. My major concern was to get the aircraft back on the ground. Several times was distracted bet ATC and I had to remind ATC that we an emergency aircraft and required immediate landing. Originally they gave us Runway 10 and then requested and received Runway 9. The odor never entered the cockpit and after landing I learned that the odor had dissipated before landing.


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


Synopsis: A B737-700 aft cabin initially filled with a strong acrid odor which eventually was detected through out the cabin so the Captain declared an emergency and returned to the departure airport.