A fatal helicopter crash southeast of Phoenix involved a slackline, also known as a highline, which investigators say the aircraft struck before plunging into a canyon.
The crash occurred Jan. 2 in Telegraph Canyon, south of Superior and about 65 miles east of Phoenix. Authorities said preliminary evidence indicates that a recreational slackline more than one kilometer long had been strung across a mountain range in the area at the time of the crash.
The helicopter was carrying four people, all of whom were killed, according to the Pinal County Sheriff’s Office.
Here’s what investigators and aviation records show so far about how a recreational slackline stretched across a canyon may have factored into a fatal helicopter crash near Superior.
What authorities say happened
An eyewitness who called 911 reported seeing the helicopter strike a portion of the line before crashing into Telegraph Canyon, according to the Pinal County Sheriff’s Office.
Federal aviation records show a notice to air men, known as a NOTAM, warned pilots of a tight rope obstruction in the area during the time of the crash.
A NOTAM is an advisory issued by the Federal Aviation Administration to alert pilots to potential hazards such as obstructions, but the FAA has not said whether the pilot was aware of the notice or whether it was reviewed before the flight.
The FAA and the National Transportation Safety Board are investigating the crash. Authorities have said additional information will be released as the investigation continues.
Pinal County Sheriff’s Office vehicles near Telegraph Canyon, south of Superior, where authorities responded to a helicopter crash that killed four people on Jan. 2, 2026.
What is a slackline or highline?
According to the International Slackline Association, a slackline, or highline, is a narrow strip of nylon or polyester webbing tightened between two fixed anchor points, such as trees or rock formations, and used for balancing.
The association says that when a slackline is installed across a canyon or at significant heights, it is commonly referred to as a highline.
The slackline association said in a statement that the helicopter struck a highline and that no highliners were on the line at the time of the incident.
The organization said the line had aviation markers attached, but investigators have not said whether those markers were visible at the time of the crash or met any specific standards.
Why slacklines can intersect with helicopter flight paths
Helicopters often operate at lower altitudes than planes, particularly in mountainous or remote areas, which can increase the likelihood of encounters with temporary obstructions such as cables, wires or slacklines, according to federal aviation safety guidance.
Investigators have not said whether altitude, visibility or terrain played a role in the crash.
What we know: Families ID 4 killed in Arizona helicopter crash in Telegraph Canyon
Rey Covarrubias Jr. covers grocery shopping, business and breaking news for The Arizona Republic and azcentral.com. Email him at: rcovarrubias@azcentral.com, and connect with him on Instagram, Threads, Bluesky and X (formerly Twitter) at @ReyCJrAZ.
This article originally appeared on Arizona Republic: Slackline may have caused fatal Arizona helicopter crash
