A B727-200 incurred damage to the right outboard flap when lowered onto a parked tug.

Attributes
ACN	474091
Time
Date	200005
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	474091
Person 2
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : airframe technician : powerplant
Events
Anomaly	aircraft equipment problem : critical ground encounters : vehicle maintenance problem : improper maintenance non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other other other
Factors
Maintenance	performance deficiency : inspection performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Maintenance Human Performance Environmental Factor Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

After reporting a hydraulic drip and puddle under the aircraft, maintenance could not find the source. Requested we drop the flaps and exercise the controls and brakes. After mechanic cleared me, I dropped the flaps and started to move the controls. A dull bang was heard and the aircraft jerked. I at first thought it was a surge in the hydraulic system. The flight engineer then came back into the cockpit and informed me that the right outboard flap had hit a tug. Mechanic then informed me after I looked at the damage that he had flat misjudged how close the tug was.

Original NASA ASRS Text

Title: A B727-200 INCURRED DAMAGE TO THE R OUTBOARD FLAP WHEN LOWERED ONTO A PARKED TUG.

Narrative: AFTER RPTING A HYD DRIP AND PUDDLE UNDER THE ACFT, MAINT COULD NOT FIND THE SOURCE. REQUESTED WE DROP THE FLAPS AND EXERCISE THE CTLS AND BRAKES. AFTER MECH CLRED ME, I DROPPED THE FLAPS AND STARTED TO MOVE THE CTLS. A DULL BANG WAS HEARD AND THE ACFT JERKED. I AT FIRST THOUGHT IT WAS A SURGE IN THE HYD SYS. THE FE THEN CAME BACK INTO THE COCKPIT AND INFORMED ME THAT THE R OUTBOARD FLAP HAD HIT A TUG. MECH THEN INFORMED ME AFTER I LOOKED AT THE DAMAGE THAT HE HAD FLAT MISJUDGED HOW CLOSE THE TUG WAS.

Data retrieved from NASA's ASRS site as of July 2007 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.