Date: 201201
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Climb
ATC / advisory: TRACON ZZZ
Aircraft component: Leading Edge Flap
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Not Flying; Captain
Anomaly: Aircraft Equipment Problem Critical
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency
Contributing factors: Procedure; Aircraft
Primary problem: Aircraft

Narrative: On departure; during flap retraction; we experienced a 'Leading Edge Disagreement' (amber) light on the forward panel. We decided upon an appropriate speed (220 KIAS initially with flaps at 1 degree). Captain 'worked' the checklist as I communicated with ATC and flew the airplane. Captain declared the emergency. We received vectors while Captain finished the checklist. He did a superb job supervising the event; and we prepared for landing on the longest runway available and coordinated with ATC to have CFR ready as we were landing very fast and over weight. We landed; flaps 15; approximately 177 KIAS; at approximately 153;500 LBS. After an uneventful landing; we remained in contact with CFR; no smoke or any other abnormalities noted from CFR; who followed us to the gate. Kudos to our training department; have done this in the simulator; and it made this event much more comfortable. Also; this event occurred as a 'repeat' item. Reviewing the logbook prior to departure; we noted the airplane had experienced a LE Flap problem a few days prior.


Second narrative: Upon departure and aircraft clean-up the 'LE FLAPS TRANSIT' light remained illuminated. Informed ATC we may have to return and requested a few minutes to review our procedures. ATC put us in a vectored holding pattern at 7;000 FT. First Officer pilot flying and Captain pilot not flying. [We] reviewed QRH procedure for 'LE FLAPS TRANSIT' light under Flight Controls. Conditions reviewed were as follows: Trailing edge flaps up; no roll encountered; extended flaps to 1 then retracted flaps up; LE FLAPS TRANSIT light remained illuminated; checked LE DEVICES annunciator panel and more than one leading edge device was illuminated. Checked emergency landing data distance and landing data card for flaps 15. Read all procedural notes. Captain declared emergency with ATC and requested landing on longest runway. Planned and executed a flaps 15 landing (Vref 15 + 15 KTS). Flew an ILS approach but flattened out the last 300 FT to touchdown to minimize sink rate. [We] landed on speed in the touchdown zone using autobrakes to about 50 KTS ground speed. Discussed overheat brakes or any unusual smoke or other potential problems with ARFF....none noted. ARFF followed aircraft to parking and shutdown. [We] made two entries in the logbook; LE Flaps Transit light AND Overweight landing. Note: the LE Flaps Transit light was a repeat write-up.


Synopsis: B737-800 flight crew experiences a LE flap transit light after flap retraction. QRH procedures do not remedy the situation and flight returns to departure airport for a partial flap landing.