Skip Ribbon Commands
Skip to main content
Aviation Accident

Quick Launch

NTSB Identification: OPS17IA010
Incident occurred Friday, December 16, 2016 in Mt. Wilson, CA
Probable Cause Approval Date: 05/07/2019
Aircraft: BOEING 777, registration:
Injuries: Unavailable

NTSB investigators used data provided by various sources and may have traveled in support of this investigation to prepare this aircraft incident report.

A near controlled flight into terrain (CFIT) incident occurred near Mt. Wilson, California, when a Boeing 777-300 departing Los Angeles International Airport (LAX) was instructed to turn left toward rising terrain after departure from runway 07R. The aircraft was operating on a 14 Code of Federal Regulations Part 129 international flight. Air traffic control services were provided by the Federal Aviation Administration Southern California Terminal Radar Approach Control (SCT TRACON). There was no damage reported to the aircraft, and no reported injuries to the passengers or crew.

Due to weather in the area, LAX was operating in an east flow configuration with aircraft departing to the east. The Boeing 777-300 pilot contacted the SCT controller and was given an initial climb to 7,000 feet. A short time later, the SCT controller instructed the pilot to turn left to a heading of 180 degrees which required a left 270 degree turn. The turn resulted in the aircraft turning toward rising terrain and back toward the airport; normal procedures in an east flow would have been for a right turn to a heading of 180 degrees. While in the left turn, the pilot requested a high speed climb which resulted in the aircraft accelerating beyond the 250 knot LAX class B speed restriction and required additional airspace in order to complete an assigned turn. After recognizing the aircraft was in a left turn, the SCT controller issued the crew a right turn to a heading of 180 degrees. As the aircraft began to turn right, the air traffic controller instructed the crew to expedite the turn due to recognizing a developing proximity issue with another aircraft that had departed from LAX. The air traffic controller stopped the climb of the B777-300 and issued a left turn to a heading of 270 degrees. These turns in quick succession, combined with the speed of the aircraft, resulted in the flight tracking northbound toward rising terrain. The closest lateral and vertical proximity between the airplane and terrain/obstructions was about 0.3 miles and 0 ft, respectively, which is less than the minimum separation requirements.


The National Transportation Safety Board determines the probable cause(s) of this incident as follows:
  • The incident was caused by the air traffic controller assigning the pilots a left turn instead of the required right turn after departure which placed the aircraft in an unsafe proximity with terrain and obstructions. Contributing to the incident was the air traffic controller's inadequate recovery technique during the development of the incident.