20101218054602A

Accident · Substantial damage

FAA accident report · Boeing 737-7H4 · Philadelphia, PA · December 18, 2010

Date
December 18, 2010 · 11:10 local
Place
Philadelphia, PA
Airport
Philadelphia International
Phase of flight
Ground/Ramp/Ma
Operating rules
Air carrier (Part 121)
Operator
SWAA
Collision
Collision on the ground
Damage
Substantial damage
Aircraft
N913WN
NTSB investigation
NTSBDCA11CA014
Reported as
Boeing 737-7H4
Reported engine
CFM International CFM56-7B24
People aboard
98
Fatal injuries
0
Other injuries
0
Pilot’s certificate
Airline transport
Pilot’s flight hours
0 total7,101 in this make and model131 in the last 90 days

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

On December 18, 2010, southwest airlines (swa) flight 3944 (N650SW) received clearance from phl ramp control 2 for pushback from gate E-11 at 1103 EST. It was subsequently pushed onto the centerline for the east taxiway between terminals e & f and disconnected from the pushback tug. At 11:06 EST, swa flight 2592 (N913WN) called for and received push clearance from gate E-9 from phl ramp control 2. Aircraft N650SW was positioned on the taxiway centerline behind gate E-9 with both engines running, parking brake set and called ramp 2 for taxi clearance at 11:06 EST (approximately 30 seconds after N913WN'S call for push clearance). As N913WN was being pushed in a turn to align with the centerline of the taxiway with #2 engine running, its aft left wing stuck the right winglet of N650SW. The lower left horizontal stabilizer of N913WN also contacted the top of the right horizontal stabilizer of N650SW. The stabilizer damage appeared to consist mostly of paint transfer. The damage to N650SW appeared to be confined to the winglet. The damage to N913WN was substantial and resulted in a breach of the fuel surge tank and substantial damage to the rear spar of the left wing. There were no reported injuries on either aircraft to the passengers. The tapes from ramp 2 recorded the clearance given to the flight crew of N913WN as "push approved, call for taxi." The flight crew conveyed this information to the push crew. During interviews with both on-scene witnesses and the push crew for N913WN, it was determined that there was loss of communication and/or visual contact between the tug driver and wing walker. The wing walker was aware of the aircraft in the alley behind N913WN and was signaling for the tug driver to stop the push. The tug driver stated that while he knew the approximate position of aircraft in the alley, he could not see the aircraft from his position and he commenced his push once he received the push clearance from the flight crew. The breakdown in this vital link between the wing walker and the tug driver contributed to the collision of these two aircraft. There was no report of the collision to phl operations, ramp 2 or any requests made for Philadelphia fire and rescue response. Approximately 1 hour after the collision, the aircraft were towed apart and back to the gate with passengers on-board. This accident highlights several concerns over post-accident passenger safety procedures and possible breakdowns in notification and communication procedures. These items will be forwarded to the appropriate organizations for their review and action. See related atqa# AEA1710036 for N650SW

As the FAA filed it

ON DECEMBER 18, 2010, SOUTHWEST AIRLINES (SWA) FLIGHT 3944 (N650SW) RECEIVED CLEARANCE FROM PHL RAMP CONTROL 2 FOR PUSHBACK FROM GATE E-11 AT 1103 EST. IT WAS SUBSEQUENTLY PUSHED ONTO THE CENTERLINE FOR THE EAST TAXIWAY BETWEEN TERMINALS E & F AND DISCONNECTED FROM THE PUSHBACK TUG. AT 11:06 EST, SWA FLIGHT 2592 (N913WN) CALLED FOR AND RECEIVED PUSH CLEARANCE FROM GATE E-9 FROM PHL RAMP CONTROL 2. AIRCRAFT N650SW WAS POSITIONED ON THE TAXIWAY CENTERLINE BEHIND GATE E-9 WITH BOTH ENGINES RUNNING, PARKING BRAKE SET AND CALLED RAMP 2 FOR TAXI CLEARANCE AT 11:06 EST (APPROXIMATELY 30 SECONDS AFTER N913WN'S CALL FOR PUSH CLEARANCE). AS N913WN WAS BEING PUSHED IN A TURN TO ALIGN WITH THE CENTERLINE OF THE TAXIWAY WITH #2 ENGINE RUNNING, ITS AFT LEFT WING STUCK THE RIGHT WINGLET OF N650SW. THE LOWER LEFT HORIZONTAL STABILIZER OF N913WN ALSO CONTACTED THE TOP OF THE RIGHT HORIZONTAL STABILIZER OF N650SW. THE STABILIZER DAMAGE APPEARED TO CONSIST MOSTLY OF PAINT TRANSFER. THE DAMAGE TO N650SW APPEARED TO BE CONFINED TO THE WINGLET. THE DAMAGE TO N913WN WAS SUBSTANTIAL AND RESULTED IN A BREACH OF THE FUEL SURGE TANK AND SUBSTANTIAL DAMAGE TO THE REAR SPAR OF THE LEFT WING. THERE WERE NO REPORTED INJURIES ON EITHER AIRCRAFT TO THE PASSENGERS. THE TAPES FROM RAMP 2 RECORDED THE CLEARANCE GIVEN TO THE FLIGHT CREW OF N913WN AS "PUSH APPROVED, CALL FOR TAXI." THE FLIGHT CREW CONVEYED THIS INFORMATION TO THE PUSH CREW. DURING INTERVIEWS WITH BOTH ON-SCENE WITNESSES AND THE PUSH CREW FOR N913WN, IT WAS DETERMINED THAT THERE WAS LOSS OF COMMUNICATION AND/OR VISUAL CONTACT BETWEEN THE TUG DRIVER AND WING WALKER. THE WING WALKER WAS AWARE OF THE AIRCRAFT IN THE ALLEY BEHIND N913WN AND WAS SIGNALING FOR THE TUG DRIVER TO STOP THE PUSH. THE TUG DRIVER STATED THAT WHILE HE KNEW THE APPROXIMATE POSITION OF AIRCRAFT IN THE ALLEY, HE COULD NOT SEE THE AIRCRAFT FROM HIS POSITION AND HE COMMENCED HIS PUSH ONCE HE RECEIVED THE PUSH CLEARANCE FROM THE FLIGHT CREW. THE BREAKDOWN IN THIS VITAL LINK BETWEEN THE WING WALKER AND THE TUG DRIVER CONTRIBUTED TO THE COLLISION OF THESE TWO AIRCRAFT. THERE WAS NO REPORT OF THE COLLISION TO PHL OPERATIONS, RAMP 2 OR ANY REQUESTS MADE FOR PHILADELPHIA FIRE AND RESCUE RESPONSE. APPROXIMATELY 1 HOUR AFTER THE COLLISION, THE AIRCRAFT WERE TOWED APART AND BACK TO THE GATE WITH PASSENGERS ON-BOARD. THIS ACCIDENT HIGHLIGHTS SEVERAL CONCERNS OVER POST-ACCIDENT PASSENGER SAFETY PROCEDURES AND POSSIBLE BREAKDOWNS IN NOTIFICATION AND COMMUNICATION PROCEDURES. THESE ITEMS WILL BE FORWARDED TO THE APPROPRIATE ORGANIZATIONS FOR THEIR REVIEW AND ACTION. SEE RELATED ATQA# AEA1710036 FOR N650SW

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.

Other aircraft in the event · 1

Each aircraft in a collision has its own report.

Other reports on N913WN · 1

Matched to the same aircraft by N-number and date.