Date: 201211
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Mission: Passenger
Flight phase: Takeoff / Launch
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Exterior Pax/Crew Door
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Other / Unknown
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Attendant; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: On initial climb and less than 200 feet RA as PF I had noticed pressure on my ears that was similar to that of an excessive climb rate. I then observed the cabin climb rate was in excess of 1;000 feet per minute. At that time I also got a chime from the Lead Flight Attendant informing me that the L-1 door had a gap and was not completely closed. The Lead stated that the gap was big enough to slide his fingers through the gap. At the time of departure the aircraft weighed approximately 134;000 lbs. We contacted Dispatch and notified them of our situation and intentions to burn fuel down to landing weight of 128;000 lbs and return for landing. We ran the Weight Balance for 128;000 lb landing and determined that we needed less than 5;000 feet of runway. Operations also concurred and supported our decision to reduce our landing weight and return to field. Declared emergency. Notified Operations. Circled over the airport at 180 knots with the gear down flaps 15 at 4;000 feet MSL for 40 minutes. Returned to departure airport. Have gate agent verify that the door is completely sealed when door is shut. My understanding is that is common problem mechanically for the L-1 door.


Second narrative: During initial climb; the aircraft failed to pressurize properly. No door annunciators were illuminated; but the pressurization gauge confirmed the lack of pressurization. No pressurization annunciators were illuminated. The Captain was PF; and I was PNF. We coordinated with Tower to level off in our initial climb at 3;500 feet. Our Lead Flight Attendant contacted us on the flight deck; stating that the L1 door was making a lot of noise; and that he could put his fingers through the open space surrounding the door. Due to the noise; he was unable to hear our responses well. We stated that we were working on the problem and would get back to him shortly. We discussed the problem and options available. We contacted ATC; declaring an emergency condition. A second Flight Attendant attempted to communicate with us; but could not hear us over the cabin noise near the L1 door. Later we established communications with the aft Flight Attendant and exchanged information and stated that we would likely return due to the pressurization problem. We accepted vectors from Tower; and later Departure to stay near the airport. The Captain maintained control of the aircraft and managed ATC communications; while I contacted Dispatch/Maintenance. We again reviewed our options; came up with an initial plan to return to the airport; and notified the FA's of our plan. After burning fuel to meet landing weight; the Captain landed the aircraft without any further complication. A normal landing was accomplished at a landing weight of 127;100 lbs. (no overweight landing). Passengers were deplaned and Maintenance met the aircraft. Good crew coordination during this irregular situation.Although the cabin door handle was confirmed fully closed by the flight attendants; the door failed to seal properly. Maintenance later inspected the door for defects and found no discrepancies in it's' operation. It was reported by Maintenance that this may happen occasionally with the 737 due to the door's cam lock design. The aircraft was later returned to service and no further problems with the pressurization system were noted on the subsequent flight.


Synopsis: B737-700 flight crew reports failure of the aircraft to pressurize after takeoff and is informed shortly by the Lead Flight Attendant that the forward entry door is not sealed properly with a gap along the bottom of the door. Crew elects to return to the departure airport after burning down to landing weight.