Date: 201301
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: B737-300
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Flap/Slat Indication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Human factors: Situational Awareness; Confusion
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Less Severe
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Equipment Problem Dissipated; Flight Crew Executed Go Around / Missed Approach; General Maintenance Action; General Declared Emergency
Contributing factors: Human Factors; Aircraft
Primary problem: Aircraft

Narrative: Captain was Pilot Flying on visual approach.  He called for Flaps 5 and I moved the handle to that position.  Flaps indicator showed slight trailing edge device split and total flap deployment of only two to three degrees rather than the selected five.  Overhead leading edge device panel indicated normal leading edge device extension.  There was no abnormal roll of the aircraft.  Captain then called for Flaps 10 and I selected the handle to that position.  There was no further movement of the pointers on the trailing edge indicator. However; the leading edge device indicator indicated that leading edge devices had moved to the full extend position.  Again; there was no abnormal roll of the aircraft.  Captain then called for landing gear down and Flaps 15; and I complied with that request.  Again; there was no further movement of the pointers on the trailing edge flap indicator.  At this point we were rapidly approaching the runway and the Captain and I agreed a go-around was necessary.  I informed ATC and the Captain began a go-around.  We concurred that the flaps and landing gear would be left in their current configuration.  The Captain directed me to run the checklist in the QRH while he flew the aircraft and communicated with ATC.  At some point during the go-around; the trailing edge flap indicator moved to the selected (Flaps 15) position with no asymmetry.  I was momentarily confused with which checklist to use; but chose the Flaps Trailing Edge: Symmetrical Non-Normal/No Flaps Checklist.  The Captain concurred.  This checklist directed us to land with Flaps 15; which we did.  While I was running the checklist; the Captain declared an emergency as a precaution. We made an uneventful landing; and then taxied to the gate.  At the first sign of any abnormal indication; we should have consulted the QRH.


Second narrative: During approach the flap gauge did not go to the commanded selection of Flaps 5 degrees.  The overhead lights indicated good extension of the LED's.  I then commanded the flaps to 10 degrees.  The flaps gauge stayed at just past two degrees but the LED [Leading Edge Device] lights indicated full LED extension.  The aircraft felt/responded like the flaps were at 10 degrees.  I then commanded landing gear down; Flaps 15 degrees.  The flap gauge stayed at just past two degrees but the aircraft responded normally like flaps were at 15 degrees.  I elected to initiate a visual go-around.  I left the flaps at the commanded position 15 and left the gear down (horn nuisance.)  ATC was informed as well. I asked my First Officer to run the QRH procedure for non-normal flaps while I flew the aircraft and handled ATC.  The QRH procedure was in question by my First Officer but we did get the proper QRH procedure done (flaps non-normal 15 or better.)  The flap gauge did indicate 15 degrees normal two to three minutes after the go-around was initiated.  An emergency was declared with ATC.  The cabin crew was informed as well as the passengers.  The landing was uneventful other than a Flaps 15 landing.  The airport emergency vehicles were canceled as they were not needed.  At the gate; I contacted Dispatch via phone and Maintenance Control and discussed the event in detail.  A logbook writeup was made at the gate and a person to person discussion with a Maintenancee employee took place to further describe the event.  At no time did I feel the aircraft or souls onboard were in jeopardy.The crew action is valid and warrants no further enhancement.  A possible revision to the QRH on keeping the two non-normal flap procedures separate could help.  Also; crew training on this type of procedure during the PT would help as well.


Synopsis: B737-300 flight crew experiences a trailing edge flap failure to move to the commanded position during approach.  The flaps stopped moving at 2 degrees but the flap handle was moved from 5 to 10 to 15 degrees with no apparent movement.  A go-around was initiated without changing gear or flap positions and at some point TE flap position was noted at 15 degrees.  A 15 degree TE flap landing ensues.