Narrative:

While I was waiting for aircraft to return from the blast fence to park in front of bay 1; aircraft was being pushed out of bay 2 to complete its leak checks. I noticed that aircraft was equipped with winglets making the area that we had to park in smaller than usual. I then noticed that aircraft was not parked on the correct 'J' line in front of bay 2. As I noted this I looked back to see aircraft had returned from the blast fence and was attempting to turn and park in front of bay 1; I attempted to guide the aircraft in to the left of the usual 'J' line. Due to the tight areas in front of the hangar this is not an uncommon practice. I had a mechanic watching the right wing of aircraft to make sure we had clearance. I watched his signals as we slowly brought the aircraft in. I looked at his signal and I saw his hands were 2-3 ft apart. I interpreted this as the fact that I had that much clearance between aircraft. I brought the aircraft forward; looked at the flight deck for a second and then looked back at the wing walker to see his hands crossed. I attempted to signal the mechanics in the flight deck to stop but it was too late; the wingtips collided. I then realized that the wing walker was trying to tell me I only had 2-3 ft of forward clearance not side clearance. I'm including the names of the wing walker; the 2 mechanics that were taxiing the aircraft for reasons of detail as it was my fault this happened. I'm supposed to be the eyes for the taxi crew telling them it's ok to enter. I'm responsible I made the mistake.

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Original NASA ASRS Text

Title: A B737-300 LEAD MECHANIC GUIDING THE PARKING OF A TAXIED ACFT; DESCRIBES THE CHAIN OF EVENTS THAT LED TO BOTH WINGLETS BEING DAMAGED.

Narrative: WHILE I WAS WAITING FOR ACFT TO RETURN FROM THE BLAST FENCE TO PARK IN FRONT OF BAY 1; ACFT WAS BEING PUSHED OUT OF BAY 2 TO COMPLETE ITS LEAK CHKS. I NOTICED THAT ACFT WAS EQUIPPED WITH WINGLETS MAKING THE AREA THAT WE HAD TO PARK IN SMALLER THAN USUAL. I THEN NOTICED THAT ACFT WAS NOT PARKED ON THE CORRECT 'J' LINE IN FRONT OF BAY 2. AS I NOTED THIS I LOOKED BACK TO SEE ACFT HAD RETURNED FROM THE BLAST FENCE AND WAS ATTEMPTING TO TURN AND PARK IN FRONT OF BAY 1; I ATTEMPTED TO GUIDE THE ACFT IN TO THE L OF THE USUAL 'J' LINE. DUE TO THE TIGHT AREAS IN FRONT OF THE HANGAR THIS IS NOT AN UNCOMMON PRACTICE. I HAD A MECH WATCHING THE R WING OF ACFT TO MAKE SURE WE HAD CLRNC. I WATCHED HIS SIGNALS AS WE SLOWLY BROUGHT THE ACFT IN. I LOOKED AT HIS SIGNAL AND I SAW HIS HANDS WERE 2-3 FT APART. I INTERPED THIS AS THE FACT THAT I HAD THAT MUCH CLRNC BTWN ACFT. I BROUGHT THE ACFT FORWARD; LOOKED AT THE FLT DECK FOR A SECOND AND THEN LOOKED BACK AT THE WING WALKER TO SEE HIS HANDS CROSSED. I ATTEMPTED TO SIGNAL THE MECHS IN THE FLT DECK TO STOP BUT IT WAS TOO LATE; THE WINGTIPS COLLIDED. I THEN REALIZED THAT THE WING WALKER WAS TRYING TO TELL ME I ONLY HAD 2-3 FT OF FORWARD CLRNC NOT SIDE CLRNC. I'M INCLUDING THE NAMES OF THE WING WALKER; THE 2 MECHS THAT WERE TAXIING THE ACFT FOR REASONS OF DETAIL AS IT WAS MY FAULT THIS HAPPENED. I'M SUPPOSED TO BE THE EYES FOR THE TAXI CREW TELLING THEM IT'S OK TO ENTER. I'M RESPONSIBLE I MADE THE MISTAKE.

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.