BOEING 737 near Denver, CO — 2015-08-05

Probable cause

The gate lead/pushback driver's failure to recognize that the provisioning truck was within the safety zone of the gate during his walkaround due to distractions, which resulted in the subsequent collision between the airplane and the truck. Contributing to the collision was the provisioning truck driver's failure to recognize he was parked in the safety zone of an active gate adjacent to his assigned gate, and the guide agent's improper assumption that the safety zone was properly cleared by the gate lead/pushback driver.

NTSB narrative

During the pushback of a scheduled domestic passenger flight, the airplane's left wing collided with a provisioning truck, rolling the truck onto its side and resulting in minor damage to the airplane. The truck driver stated that he was waiting to service an inbound airplane at the adjacent gate and was likely parked within the safety zone of the incident airplane's gate. The gate lead/pushback driver for the incident airplane stated that he walked past the truck during the pre-pushback walk around but did not recall seeing the truck within the safety zone. The gate lead reported problems with his headset and personal life stress. It is likely that the gate lead was distracted by both during his walk around. Additionally, a guide agent positioned at the airplane's right wing stated that he saw the provisioning truck but assumed that it was not an issue since the gate lead had conducted a walkaround before pushback.

Analysis

Primary failure mode

Human factors

First missed decision gate

Lead agent should have ensured safety area was clear before pushback.

NTSB coding

• Ground collision · Pushback/tow-engine oper
• Attention / Monitoring

Evidence available

• Video
• 11 docket documents

Docket documents11

• Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1form
• Interview Summary Notes - Guide Agent - McCormackinterview
• Interview Summary Notes - Provisioning Agent - Shiellyinterview
• Interview Summary Notes - Pushback Driver - Jefferiesinterview
• Provisioning Truck Agent Statementinterview
• Ramp Employee Statementsinterview
• Statement of Party Representatives to NTSB Investigationinterview
• DEN Gate 24, 26, & 28other
• SWA Safety Alert - Ground Ops and Provisioningother
• Southwest Airlines Ground Ops Excerptsother
• Video Summaryvideo

Related mishaps

• Bombardier CL 600 2C10

  2019-03-10 · Charlotte, NC

• BOEING 737-924ER

  2017-09-12 · Los Angeles, CA