WEEK 2
H2F brings you the ‘helicopter mayday of the week’ with a short accident report summary. I tell you what happened. You think more about why it happened. We all learn from it. Because that’s what accident reporting is for.
TITLE
Rescue net and occupants impact utility pole during long-line extraction, causing serious injury.
WHAT?
A helicopter crew was dispatched to extract an injured hiker using a long-line rescue net system. After flying to the scene, the pilot conducted an aerial recce, observed a nearby utility pole, and landed in a nearby area to prepare for the extraction. The helicopter then repositioned above the hiker, and a rescue net suspended from a long line was lowered. The injured hiker and a firefighter entered the net, and the helicopter the extraction during which the suspended load contacted a utility pole.
WHERE?
A hiking trail lookout near Honolulu, Hawaii. The operating area included mountain terrain and fixed obstacles, notably a utility pole located close to the extraction path.
WHEN?
Accident 2016. NTSB report published 2020.
HOW?
The extraction used a rescue net suspended on a long line approximately 75–100 feet beneath the helicopter. After the occupants entered the net, the pilot initiated ascent. During the climb, a strong gust caused rapid ascent and lateral movement of the helicopter, which induced swing in the long line. Despite attempts to control the motion, the net swung into the utility pole, resulting in a hard impact.
CONDITIONS?
Operational conditions included strong tropical easterly winds and gusts affecting aircraft handling and external load stability. Weather advisories indicated turbulence in terrain-influenced airflow, and the rescue took place in an area where local terrain produced changing wind patterns.
OUTCOME?
The firefighter in the rescue net was electrocuted after the net contacted the utility pole and subsequently fell about 20 feet, sustaining serious injuries. The pilot, another crewmember, and the hiker were not injured. The helicopter sustained no damage.
WHY?
- The extraction occurred close to a fixed obstacle that had previously been identified during the site recce.
- Strong, gusting winds and terrain-influenced airflow affected aircraft and long-line behavior during the climb.
- The long line and suspended load developed lateral movement and swing shortly after ascent began.
- The pilot was simultaneously managing aircraft control, wind effects, and long-line stability during a dynamic rescue maneuver.
- The operator’s procedures emphasized that insertion areas be safe and free of obstructions, highlighting the importance of obstacle management in this type of operation.
REFERENCE?
National Transportation Safety Board. (2020, September 14). Aviation investigation final report: Accident number WPR16LA175 (McDonnell Douglas Helicopter 500N, N5232G). National Transportation Safety Board. https://data.ntsb.gov/Docket?ProjectID=93977
Click here to download the report.
Note:
Accident reports selected from the following open source databases: US NTSB; UK AAIB; Flight Safety Foundation’s Aviation Safety Network; Australia’s ATSB. Ireland’s AAIU; Taiwan’s TTSB; France’s BEA; Spain’s CIAIAC. Germany’s BFU.
competentaviators.com 