B757 flight crew has a thrust reverser unlock light during cruise; declares emergency and diverts.

Attributes
ACN	722537
Time
Date	200612
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	722537
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : thrust reverser warning other flight crewa other flight crewb
Resolutory Action	flight crew : landed as precaution flight crew : diverted to another airport flight crew : declared emergency
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

The crew before us returned to ZZZ1 with right reverser light no yaw airspeed change buffet. Maintenance cycled reverser and light went out. Signed off logbook. On our departure the right reverser light came on during climb out then went out. It came on again during cruise. Called maintenance control and dispatch and decided to divert to ZZZ because we would have the same problem in ZZZ2 and ZZZ had a long runway and we did not have to fly another 1000 mi with the light on. We had no yaw buffet or airspeed changes.

Original NASA ASRS Text

Title: B757 FLT CREW HAS A THRUST REVERSER UNLOCK LIGHT DURING CRUISE; DECLARES EMER AND DIVERTS.

Narrative: THE CREW BEFORE US RETURNED TO ZZZ1 WITH R REVERSER LIGHT NO YAW AIRSPD CHANGE BUFFET. MAINT CYCLED REVERSER AND LIGHT WENT OUT. SIGNED OFF LOGBOOK. ON OUR DEP THE R REVERSER LIGHT CAME ON DURING CLBOUT THEN WENT OUT. IT CAME ON AGAIN DURING CRUISE. CALLED MAINT CTL AND DISPATCH AND DECIDED TO DIVERT TO ZZZ BECAUSE WE WOULD HAVE THE SAME PROB IN ZZZ2 AND ZZZ HAD A LONG RWY AND WE DID NOT HAVE TO FLY ANOTHER 1000 MI WITH THE LIGHT ON. WE HAD NO YAW BUFFET OR AIRSPD CHANGES.

Data retrieved from NASA's ASRS site as of January 2009 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.