Narrative:

I was connecting the leading edge flap and slat actuators. The flaps were in the #2 position so we would run the slat actuators to the mid position and manually push the slats up to connect them. After clearing each wing I ran the (mule) at low pressure to extend all actuators and I did not notice that the #1 krueger flap actuator had been tied up inside the flap well and extended into the leading edge of the wing resulting in a dent. No lock out/tag out procedures were used and no streamers for the actuator being tied up.

Related reports:

Google
 

Original NASA ASRS Text

Title: Two Mechanics report damage to a B737 wing leading edge while attempting to position hydraulic actuators to allow reconnection to the leading edge high lift devices. One actuator had been tied up by a previous Mechanic and extended into the leading edge.

Narrative: I was connecting the leading edge flap and slat actuators. The flaps were in the #2 position so we would run the slat actuators to the mid position and manually push the slats up to connect them. After clearing each wing I ran the (mule) at low pressure to extend all actuators and I did not notice that the #1 Krueger flap actuator had been tied up inside the flap well and extended into the leading edge of the wing resulting in a dent. No lock out/tag out procedures were used and no streamers for the actuator being tied up.

Data retrieved from NASA's ASRS site as of April 2012 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.