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Helicopter collides with slackline in Arizona canyon, killing four
A helicopter crashed into an extreme slackline spanning a remote Arizona canyon on 2 January, killing all four people on board, authorities said. The incident occurred near Telegraph Canyon, east of Phoenix, where a kilometer-long slackline had been strung across the mountainous terrain for highlining-a sport involving walking or balancing on a suspended fabric line.
Witness reports and initial findings
The Pinal County Sheriff's Office stated that a witness saw the helicopter hit part of the slackline before plummeting into the canyon. No one was on the slackline at the time of the crash, according to the National Transportation Safety Board (NTSB). The wreckage was later moved to a secure facility for further analysis.
Investigators have not yet determined whether the slackline caused the crash. NTSB spokesman Keith Holloway noted that wires, including slacklines, are often difficult for pilots to spot mid-flight. The agency has handled multiple cases of aircraft colliding with wires in the past.
Victims identified as family members from Oregon
Officials confirmed the victims as pilot David McCarty, 59, and his three nieces: Rachel McCarty, 23, Faith McCarty, 21, and Katelyn Heideman, 21. All four were from Oregon.
Safety measures and aviation alerts under scrutiny
The slackliners had filed a Notice to Air Missions (Notam), a standard aviation safety alert, before the incident. However, questions remain about whether the pilot saw the notice, which warns pilots of potential hazards like construction cranes, bird flocks, or temporary obstacles.
The International Slackline Association said the group had followed proper protocols, including attaching aviation markers to the line for visibility. The association expressed sorrow over the tragedy but emphasized that the slackliners had taken precautions.
"The FAA had been informed of the highline, and a Notam had been issued before the collision."
International Slackline Association
Criticism of the Notam system
Aviation experts have long criticized the Notam system as outdated and cumbersome. Pilots must manually sift through lengthy lists of notices, many of which may not apply to their flight paths.
"Some notices will be relevant, some won't. Some may have expired, while others are upcoming. It's up to the pilot to determine which ones matter."
Tim Kiefer, Professor of Air Traffic Management, Embry-Riddle Aeronautical University
The U.S. Department of Transportation announced plans in September to replace the "legacy and aging" Notam system by February 2026, calling it a necessary upgrade for modern aviation safety.
Investigation ongoing
The NTSB and Federal Aviation Administration (FAA) are leading the investigation. A preliminary report is expected within 30 days, though the exact cause of the crash remains undetermined. It is unclear whether slacklines have been linked to previous aviation accidents.
