WEEK 14
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
SAR helicopter main rotor strikes tree during confined-area winching operation.
WHAT?
An AW139 rescue helicopter was tasked to retrieve an injured hiker from mountainous terrain. The crew consisted of a pilot, air crew officer (ACO), paramedic, and doctor. After locating the hiker near a waterfall within a narrow re-entrant, the crew positioned the helicopter to conduct a winch insertion. While preparing to lower the paramedic, the aircraft drifted left and the main rotor struck a nearby tree that had previously been identified as the closest obstacle.
WHERE?
New South Wales, Australia, in steep mountainous terrain in the Snowy Mountains inside a confined re-entrant valley.
WHEN?
The incident occurred on 5 January 2026 at approximately 1616 local time in daylight. The ATSB final report was released on 19 May 2026.
HOW?
The crew initially assessed the insertion site and determined they would need to approach slowly up the re-entrant, then turn the helicopter around to provide a downslope escape route during winching. On approach a significant increase in power indicated the presence of a tail wind, so the pilot elected to turn the aircraft around and back up into the re-entrant. After descending into a hover in a confined area among trees, the ACO provided obstacle clearances to the pilot while alternating between cabin doors. To reduce the risk of conical spin in the confined airflow, the helicopter was positioned lower and further back into the re-entrant. Before the winch commenced, the ACO advised that the nearest obstacle was a tree approximately 10 ft above and 20ft to the left of the main rotor disk, within the pilot’s blind spot. The they then shifted attention inside the cabin to prepare the paramedic for winching, leaving the pilot solely responsible for obstacle clearance. While the ACO was ‘eye in’ the helicopter drifted left. The doctor observed the movement but hesitated to interrupt safety-critical checks. On identifying the drift the ACO issued escalating “move right” calls but during the corrective manoeuvre the main rotor blades struck the tree. The pilot immediately transitioned to forward flight and exited the confined area downslope.
CONDITIONS?
The operation was conducted in steep mountainous terrain within a challenging confined area near trees and a waterfall. The crew had assessed that the helicopter would initially be overweight for winching and burned fuel before the insertion. The hover environment involved recirculating airflow increasing hover workload and power demand. The crew was operating with minimum allowable lateral clearance from obstacles, although the nearest obstacle was obscured from the pilot’s direct view. The operator’s procedures allowed obstacle clearance of 10 ft once established in hover during daytime winching operations.
OUTCOME?
The helicopter sustained minor, repairable damage to three main blade tips, the horizontal stabiliser, and tail boom from tree debris. No injuries occurred. The pilot conducted a control check after the strike and landed safely at a nearby helipad. The hiker later walked out independently and declined medical assistance.
WHY?
The ATSB found that the crew positioned the helicopter with the nearest obstacle in the pilot’s blind spot before the pilot assumed sole responsibility for obstacle clearance while the ACO and paramedic prepared for winching. The helicopter then drifted left in hover before the ACO resumed monitoring clearances. The pilot did not detect and correct the drift toward the obstacle, resulting in the main rotor strike. Contributing operational factors included confined mountainous terrain, recirculating airflow, minimum obstacle clearances, increased hover workload, and interruption of continuous obstacle monitoring by trained crew members.
REFERENCE?
Australian Transport Safety Bureau. (2026, May 19). Main rotor strike involving Leonardo Helicopters AW139, VH-TJF, 42 km south-east of Corryong Airport, New South Wales, on 5 January 2026 (Investigation No. AO-2026-002). Australian Transport Safety Bureau. ATSB investigation report AO‑2026‑002
https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105488/pdf
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.
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