B757 crew had asymmetric trailing edge flap lockout.

Attributes
ACN	445577
Time
Date	199908
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sna.airport
State Reference	CA
Altitude	msl single value : 10000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sct.tracon tower : cyul.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : keyo
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	445577
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : declared emergency flight crew : diverted to another airport flight crew : landed in emergency condition
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft Company
Primary Problem	Aircraft

Narrative:

Diversion for flap problem. On descent into sna at 10000 ft, keyo arrival, indicating approximately 210 KTS, selected flaps 1 degree. EICAS message indicated trailing edge flap asymmetry. Requested delay vectors to accomplish appropriate checklist items. With flaps selected at 1 degree, flaps were split between 0/1. With alternate flap control, flaps were balanced at approximately 1/2 of 1 degree. Diverted to lax. Declared emergency, requested crash fire rescue equipment equipment to stand by, completed approach/landing at lax without further drama. Requested runway 25R for length. Touchdown speed approximately 180 KTS. Normal braking, rolled out long, taxied to the gate.

Original NASA ASRS Text

Title: B757 CREW HAD ASYMMETRIC TRAILING EDGE FLAP LOCKOUT.

Narrative: DIVERSION FOR FLAP PROB. ON DSCNT INTO SNA AT 10000 FT, KEYO ARR, INDICATING APPROX 210 KTS, SELECTED FLAPS 1 DEG. EICAS MESSAGE INDICATED TRAILING EDGE FLAP ASYMMETRY. REQUESTED DELAY VECTORS TO ACCOMPLISH APPROPRIATE CHKLIST ITEMS. WITH FLAPS SELECTED AT 1 DEG, FLAPS WERE SPLIT BTWN 0/1. WITH ALTERNATE FLAP CTL, FLAPS WERE BALANCED AT APPROX 1/2 OF 1 DEG. DIVERTED TO LAX. DECLARED EMER, REQUESTED CFR EQUIP TO STAND BY, COMPLETED APCH/LNDG AT LAX WITHOUT FURTHER DRAMA. REQUESTED RWY 25R FOR LENGTH. TOUCHDOWN SPD APPROX 180 KTS. NORMAL BRAKING, ROLLED OUT LONG, TAXIED TO THE GATE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.