No fatalities

Pneumatic Duct Rupture Prompts Takeoff Abort and Evacuation (N604UA)

Los Angeles, CA, US

On May 13, 1992, a Boeing 767-222 (registration N604UA) operated by United Airlines was involved in an aviation accident near Los Angeles, CA. No fatalities were reported. Investigators recorded the probable cause as: A RUPTURE IN THE AIRPLANE'S AIR CONDITION/HEAT/PRESSURIZATION/APU DUCT, ALONG ITS WELDED SEAM. CONTRIBUTING TO THE INCIDENT WAS THE MANUFACTURERS' FAILURE TO ISSUE A SERVICE BULLETIN APPLICALBE TO ALL APU DUCTS IN THE SYSTEMS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 3 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards
Boeing 767-222
Photo: Tosaka / CC BY 3.0, via Wikimedia Commons

During takeoff roll, a pneumatic supply duct ruptured, causing cabin smoke, dust, and high temperature. The captain aborted takeoff and evacuated all personnel via emergency slides.

Incident Overview

During the takeoff roll with the first officer at the controls, the pneumatic distribution supply duct ruptured. The captain noted a slight change in cabin pressure and an advisory message on the Electronic Information Crew Alarm System (EICAS) indicating a pneumatic duct leak. The first flight attendant reported smoke, dust, and elevated temperatures in the cabin.

Actions Taken

The captain assumed control of the aircraft, aborted the takeoff, and exited the runway via a midfield taxiway. After leaving the runway, the captain instructed the first officer to inspect the cabin. The first officer confirmed the flight attendant's observations and noted that passengers were coughing continuously. In response, the captain ordered an evacuation of all personnel using the emergency egress slides.

Post-Incident Examination

An examination revealed that the Auxiliary Power Unit (APU) supply duct had ruptured along a welded seam at fuselage station (FS) 1219.

All Boeing 767-300 accidents →

Frequently asked questions

What happened in the 13 May 1992 Boeing 767-222 accident near Los Angeles, CA?

During takeoff roll, a pneumatic supply duct ruptured, causing cabin smoke, dust, and high temperature. The captain aborted takeoff and evacuated all personnel via emergency slides.

Were there any fatalities in the 13 May 1992 Boeing 767-222 accident?

No fatalities were recorded in this accident.

What aircraft was involved and where did it happen?

The accident on 13 May 1992 involved a Boeing 767-222, registration N604UA, operated by United Airlines, at Los Angeles, CA.

What was the probable cause of the accident?

A RUPTURE IN THE AIRPLANE'S AIR CONDITION/HEAT/PRESSURIZATION/APU DUCT, ALONG ITS WELDED SEAM. CONTRIBUTING TO THE INCIDENT WAS THE MANUFACTURERS' FAILURE TO ISSUE A SERVICE BULLETIN APPLICALBE TO ALL APU DUCTS IN THE SYSTEMS.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X14674. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.