Medium large transport hits tow bar on initial brake release.

Attributes
ACN	305679
Time
Date	199505
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : smf
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 220 flight time total : 7000 flight time type : 3000
ASRS Report	305679
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : ground critical non adherence : published procedure other anomaly other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	none taken : unable
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

After pushback the aircraft rolled onto the disconnected tow bar. Aircraft returned to jetway for maintenance inspection, both nosewheel/tire assemblies were removed and replaced. Aircraft returned to service. After the tug driver disconnected the tow bar and headset, he did not depart but remained in front of the aircraft under the nose, not visible from the flight deck. When the marshaller was given the taxi signal they did not maintain the hold signal, momentarily moving the wands to the ready to assume control signal and back to the hold signal. During this moment the brakes were released -- the aircraft rolled onto the tow bar, and then the brakes were reapplied. Corrective action: tug drivers -- after cleared to disconnect, depart, or at least move to a position visible from the flight deck. Marshallers -- better training. Pilots -- when the procedures break down, it is our responsibility to back them up. Diligently observe the departure/tow bar and tug. Delay setting switches and performing pretaxi flow until the above is completed. Airplanes -- nose window or camera or mirrors (not likely).

Original NASA ASRS Text

Title: MLG HITS TOW BAR ON INITIAL BRAKE RELEASE.

Narrative: AFTER PUSHBACK THE ACFT ROLLED ONTO THE DISCONNECTED TOW BAR. ACFT RETURNED TO JETWAY FOR MAINT INSPECTION, BOTH NOSEWHEEL/TIRE ASSEMBLIES WERE REMOVED AND REPLACED. ACFT RETURNED TO SVC. AFTER THE TUG DRIVER DISCONNECTED THE TOW BAR AND HEADSET, HE DID NOT DEPART BUT REMAINED IN FRONT OF THE ACFT UNDER THE NOSE, NOT VISIBLE FROM THE FLT DECK. WHEN THE MARSHALLER WAS GIVEN THE TAXI SIGNAL THEY DID NOT MAINTAIN THE HOLD SIGNAL, MOMENTARILY MOVING THE WANDS TO THE READY TO ASSUME CTL SIGNAL AND BACK TO THE HOLD SIGNAL. DURING THIS MOMENT THE BRAKES WERE RELEASED -- THE ACFT ROLLED ONTO THE TOW BAR, AND THEN THE BRAKES WERE REAPPLIED. CORRECTIVE ACTION: TUG DRIVERS -- AFTER CLRED TO DISCONNECT, DEPART, OR AT LEAST MOVE TO A POS VISIBLE FROM THE FLT DECK. MARSHALLERS -- BETTER TRAINING. PLTS -- WHEN THE PROCS BREAK DOWN, IT IS OUR RESPONSIBILITY TO BACK THEM UP. DILIGENTLY OBSERVE THE DEP/TOW BAR AND TUG. DELAY SETTING SWITCHES AND PERFORMING PRETAXI FLOW UNTIL THE ABOVE IS COMPLETED. AIRPLANES -- NOSE WINDOW OR CAMERA OR MIRRORS (NOT LIKELY).

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.