After maintenance was performed on a B737-700; both an inspector and a maintenance technician missed...

Narrative:

I was performing a post dock general walk around safety inspection on an aircraft. In the left wheel well I failed to see the presence of the standby leading edge shutoff lock out tool still attached to the valve; rendering the leading edge devices inoperative in the standby mode. It was not discovered until the aircraft flew to another station where the crew found it on preflight walk around before the next flight. I believe one of the contributing factors was the color of the lock-out tool. It is a dull red color which I believe blends into the surrounding components. Another contributing factor is the maintenance task card for the post dock intermediate check- general walk around safety inspection. There is not a block that specifically states to remove this locking tool. It refers you to three different maintenance procedures for the activation of the leading edge flaps and slats. Also; if I had paid more attention to the inspection of that component in the left wheel well; I believe this would have been prevented.

Original NASA ASRS Text

Title: After maintenance was performed on a B737-700; both an Inspector and a Maintenance Technician missed seeing that a standby leading edge shutoff lock tool was still installed while performing a final walk around.

Narrative: I was performing a Post Dock General Walk around Safety Inspection on an aircraft. In the left wheel well I failed to see the presence of the Standby Leading Edge Shutoff lock out tool still attached to the valve; rendering the leading edge devices inoperative in the standby mode. It was not discovered until the aircraft flew to another station where the crew found it on preflight walk around before the next flight. I believe one of the contributing factors was the color of the lock-out tool. It is a dull red color which I believe blends into the surrounding components. Another contributing factor is the Maintenance Task Card for the Post Dock Intermediate Check- General Walk Around Safety Inspection. There is not a block that specifically states to remove this locking tool. It refers you to three different Maintenance procedures for the activation of the leading edge flaps and slats. Also; if I had paid more attention to the inspection of that component in the left wheel well; I believe this would have been prevented.

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	1338930
Time
Date	201603
Local Time Of Day	0001-0600
Environment
Light	Night
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Flap/Slat Control System
Person 1
Function	Technician
Person 2
Function	Inspector
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy

After maintenance was performed on a B737-700; both an inspector and a maintenance technician missed seeing that a standby leading edge shutoff lock tool was still installed while performing a final walk around.