An air carrier widebody transport rolled into the towbar.

Attributes
ACN	315256
Time
Date	199509
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ont
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	ground : preflight ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 100 flight time total : 12000 flight time type : 2000
ASRS Report	315256
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 90 flight time total : 12160 flight time type : 73
ASRS Report	314942
Events
Anomaly	conflict : ground critical non adherence : published procedure other anomaly other anomaly other
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	none taken : detected after the fact none taken : insufficient time
Consequence	other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Preflight normal. Left engine started during pushback. Ground crew requested 'set brakes' and captain set the parking brakes. He replied 'brakes set, cleared to disconnect.' the aircraft slowly moved forward about 3 ft while the pushback crew stated 'set brakes, set brakes!' the captain pumped the brakes to try to stop the aircraft. The hydraulic pumps were off. Inspection of the nosewheel showed a small sidewall chunk of rubber gouged out of the left nosewheel and the towbar wedged between the nosewheel tires. The station manager told us that the pushback crew was supposed to place a chock under the nosewheel before disconnect, which they failed to do. Also, a brake accumulator should supply adequate brake pressure to hold the aircraft before hydraulic pressure from the hydraulic pumps has been turned on. Suggest: 1) rechk hydraulic brake pressure when setting brakes (both crew members). 2) request confirmation that 'nosewheel is chocked.' 3) turn on hydraulic pumps before pushback and both crew members confirm 'normal hydraulic brake pressure.' supplemental information from acn 314942: pumping the brakes and scanning the cockpit, I discovered that the hydraulic system switches were not on. I am now extremely methodical of accomplishing all checklists and check the brake pressure gauge when setting the brakes. (System design allows brake handle to be set without adequate brake pressure to hold the aircraft.)

Original NASA ASRS Text

Title: AN ACR WDB ROLLED INTO THE TOWBAR.

Narrative: PREFLT NORMAL. L ENG STARTED DURING PUSHBACK. GND CREW REQUESTED 'SET BRAKES' AND CAPT SET THE PARKING BRAKES. HE REPLIED 'BRAKES SET, CLRED TO DISCONNECT.' THE ACFT SLOWLY MOVED FORWARD ABOUT 3 FT WHILE THE PUSHBACK CREW STATED 'SET BRAKES, SET BRAKES!' THE CAPT PUMPED THE BRAKES TO TRY TO STOP THE ACFT. THE HYD PUMPS WERE OFF. INSPECTION OF THE NOSEWHEEL SHOWED A SMALL SIDEWALL CHUNK OF RUBBER GOUGED OUT OF THE L NOSEWHEEL AND THE TOWBAR WEDGED BTWN THE NOSEWHEEL TIRES. THE STATION MGR TOLD US THAT THE PUSHBACK CREW WAS SUPPOSED TO PLACE A CHOCK UNDER THE NOSEWHEEL BEFORE DISCONNECT, WHICH THEY FAILED TO DO. ALSO, A BRAKE ACCUMULATOR SHOULD SUPPLY ADEQUATE BRAKE PRESSURE TO HOLD THE ACFT BEFORE HYD PRESSURE FROM THE HYD PUMPS HAS BEEN TURNED ON. SUGGEST: 1) RECHK HYD BRAKE PRESSURE WHEN SETTING BRAKES (BOTH CREW MEMBERS). 2) REQUEST CONFIRMATION THAT 'NOSEWHEEL IS CHOCKED.' 3) TURN ON HYD PUMPS BEFORE PUSHBACK AND BOTH CREW MEMBERS CONFIRM 'NORMAL HYD BRAKE PRESSURE.' SUPPLEMENTAL INFO FROM ACN 314942: PUMPING THE BRAKES AND SCANNING THE COCKPIT, I DISCOVERED THAT THE HYD SYS SWITCHES WERE NOT ON. I AM NOW EXTREMELY METHODICAL OF ACCOMPLISHING ALL CHKLISTS AND CHK THE BRAKE PRESSURE GAUGE WHEN SETTING THE BRAKES. (SYS DESIGN ALLOWS BRAKE HANDLE TO BE SET WITHOUT ADEQUATE BRAKE PRESSURE TO HOLD THE ACFT.)

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.