A B737's nose wheels turned an uncommanded 25-30 degrees as the ramp agent was installing the nose w...

Attributes
ACN	1102068
Time
Date	201307
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Nosewheel Steering
Person 1
Function	Captain Pilot Not Flying
Experience	Flight Crew Last 90 Days 150 Flight Crew Total 21200 Flight Crew Type 4000
Events
Anomaly	Aircraft Equipment Problem Critical Ground Event / Encounter Other / Unknown

Narrative:

After parking at the gate; very shortly after shutting down the left engine (the right engine had been shutdown during taxi in) and receiving the release brakes signal from the ramp agent; I felt the aircraft move laterally a small amount. Somebody from the ramp soon appeared in the cockpit and asked me to come downstairs and take a look at something. I was a bit stunned at what I saw. The nose gear had turned 25-30 degrees to the left; moving the fore and aft chocks around. At the same time a ramp agent was attempting to insert the steering bypass pin. I was told he quite luckily was not injured. I made a logbook entry about uncommanded nose gear movement.

Original NASA ASRS Text

Title: A B737's nose wheels turned an uncommanded 25-30 degrees as the Ramp Agent was installing the nose wheel bypass pin following aircraft shut down at the arrival gate.

Narrative: After parking at the gate; very shortly after shutting down the left engine (the right engine had been shutdown during taxi in) and receiving the release brakes signal from the ramp agent; I felt the aircraft move laterally a small amount. Somebody from the ramp soon appeared in the cockpit and asked me to come downstairs and take a look at something. I was a bit stunned at what I saw. The nose gear had turned 25-30 degrees to the left; moving the fore and aft chocks around. At the same time a Ramp Agent was attempting to insert the steering bypass pin. I was told he quite luckily was not injured. I made a logbook entry about uncommanded nose gear movement.

Data retrieved from NASA's ASRS site as of July 2013 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.

A B737's nose wheels turned an uncommanded 25-30 degrees as the ramp agent was installing the nose wheel bypass pin following aircraft shut down at the arrival gate.