B767 flight crew experiences an uncommanded le slat extension climbing through FL230. As quickly as ...

Narrative:

Climbing out through around 23;000 feet. I was on the service phone with a flight attendant (flight attendant) and I heard a caution sound. By the time I looked up it was gone. The captain requested a level off and advised ATC. Her and the first officer (first officer) said that the slats moved while handle was set in up position as well as EICAS listed an le slat asymmetry. She directed me to run the QRH and I did. The captain and the first officer coordinated heading back. I continued with the le slat asymmetry checklist as well as the fuel dumping checklist with the captain. We dumped gas. I got our landing performance numbers and completed the overweight landing checklist. As a crew we discussed what to do in case of a go around. We also briefed the approach. And completed all checklists. The captain and I had a discussion about landing at flaps 20 but we decided against it. We landed and stopped on the runway. Directed by the captain I got on the PA and said 'remain seated; remain seated'. I completed the hot brakes checklist. We waited on runway until the brakes cooled and we got towed to the gate. While we were in the air the captain did speak to the fas as well I did. I just don't remember the sequence of times.

Original NASA ASRS Text

Title: B767 flight crew experiences an uncommanded LE slat extension climbing through FL230. As quickly as the slat extended it retracted; but the crew elected to dump fuel and return to the departure airport for an overweight landing.

Narrative: Climbing out through around 23;000 feet. I was on the service phone with a Flight Attendant (FA) and I heard a caution sound. By the time I looked up it was gone. The captain requested a level off and advised ATC. Her and the First Officer (FO) said that the slats moved while handle was set in UP position as well as EICAS listed an LE SLAT Asymmetry. She directed me to run the QRH and I did. The Captain and the FO coordinated heading back. I continued with the LE SLAT Asymmetry checklist as well as the Fuel Dumping Checklist with the Captain. We dumped gas. I got our landing performance numbers and completed the overweight landing checklist. As a crew we discussed what to do in case of a go around. We also briefed the approach. And completed all checklists. The captain and I had a discussion about landing at Flaps 20 but we decided against it. We landed and stopped on the runway. Directed by the Captain I got on the PA and said 'Remain Seated; Remain Seated'. I completed the Hot Brakes checklist. We waited on runway until the brakes cooled and we got towed to the gate. While we were in the air the captain did speak to the FAs as well I did. I just don't remember the sequence of times.

Data retrieved from NASA's ASRS site 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.

Attributes
ACN	1207289
Time
Date	201409
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Climb
Component
Aircraft Component	Leading Edge Slat
Person 1
Function	First Officer Pilot Not Flying Relief Pilot
Experience	Flight Crew Last 90 Days 130 Flight Crew Total 5200 Flight Crew Type 700
Person 2
Function	Pilot Not Flying First Officer
Experience	Flight Crew Last 90 Days 229 Flight Crew Total 16521 Flight Crew Type 387
Events
Anomaly	Aircraft Equipment Problem Less Severe

B767 flight crew experiences an uncommanded le slat extension climbing through FL230. As quickly as the slat extended it retracted; but the crew elected to dump fuel and return to the departure airport for an overweight landing.