Ramp operation pushback instructions from ramp tower operator not followed.

Attributes
ACN	302007
Time
Date	199504
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : dtw
State Reference	MI
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 other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 6000
ASRS Report	302007
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 7880 flight time type : 4596
ASRS Report	302154
Events
Anomaly	non adherence other other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Aircraft full, lots of excess bags, a few mins late to depart gate. After requesting pushback, ramp tower told us to wait for dc-9 in alley and then cleared to pushback. I relayed this information to tug driver via intercom. While waiting, I took the opportunity to explain the delay and welcome everyone onboard via the PA. While I was making the PA, the ramp tower issued an additional restr to wait for a flight inbound and then clear to push. The first officer relayed these instructions to the tug driver and assumed he copied. A few moments later the tug driver began the push. I ended the PA when the aircraft began to move and again monitored the intercom. As we were completing the pushback, the ramp tower became very upset because we pushed prior to the inbound air carrier flight and ground control had to repos the flight. We volunteered to pull back into the gate but the ramp tower said it was too late. The tug driver said he had not heard the additional restr. Safety was not an issue, but optimum traffic flow was impacted. Moral: never assume anything. Also, I should have continued to monitor the frequencys as a backup while I gave the PA.

Original NASA ASRS Text

Title: RAMP OP PUSHBACK INSTRUCTIONS FROM RAMP TWR OPERATOR NOT FOLLOWED.

Narrative: ACFT FULL, LOTS OF EXCESS BAGS, A FEW MINS LATE TO DEPART GATE. AFTER REQUESTING PUSHBACK, RAMP TWR TOLD US TO WAIT FOR DC-9 IN ALLEY AND THEN CLRED TO PUSHBACK. I RELAYED THIS INFO TO TUG DRIVER VIA INTERCOM. WHILE WAITING, I TOOK THE OPPORTUNITY TO EXPLAIN THE DELAY AND WELCOME EVERYONE ONBOARD VIA THE PA. WHILE I WAS MAKING THE PA, THE RAMP TWR ISSUED AN ADDITIONAL RESTR TO WAIT FOR A FLT INBOUND AND THEN CLR TO PUSH. THE FO RELAYED THESE INSTRUCTIONS TO THE TUG DRIVER AND ASSUMED HE COPIED. A FEW MOMENTS LATER THE TUG DRIVER BEGAN THE PUSH. I ENDED THE PA WHEN THE ACFT BEGAN TO MOVE AND AGAIN MONITORED THE INTERCOM. AS WE WERE COMPLETING THE PUSHBACK, THE RAMP TWR BECAME VERY UPSET BECAUSE WE PUSHED PRIOR TO THE INBOUND ACR FLT AND GND CTL HAD TO REPOS THE FLT. WE VOLUNTEERED TO PULL BACK INTO THE GATE BUT THE RAMP TWR SAID IT WAS TOO LATE. THE TUG DRIVER SAID HE HAD NOT HEARD THE ADDITIONAL RESTR. SAFETY WAS NOT AN ISSUE, BUT OPTIMUM TFC FLOW WAS IMPACTED. MORAL: NEVER ASSUME ANYTHING. ALSO, I SHOULD HAVE CONTINUED TO MONITOR THE FREQS AS A BACKUP WHILE I GAVE THE PA.

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.