Fatal Wisconsin Wire Strike When Robinson R44 Repositions to Refuel

Fatal Wisconsin Wire Strike When Robinson R44 Repositions to Refuel (N529DW)

There is a theory that people let down their guard when the more complex part of a task is complete.

R44 N529DW  Wirestrike near Oshkosh, WI (Credit: via NTSB)

R44 N529DW Wirestrike near Oshkosh, WI (Credit: via NTSB)

On 9 June 2018 the pilot of Robinson R44 helicopter N529DW, operated by MF Helicopters, had just finished a low-level aerial photography flight at a charity boating event (the Four Horsemen Poker Run) along a series of lakes and rivers near Oshkosh, Wisconsin.  The US National Transportation Safety Board (NTSB) explain in their safety investigation report that after 90 minutes of photography in the Lake Winnebago area:

The pilot landed the helicopter, off-loaded the photographer, and departed to a nearby airport [Wittman Field] to refuel.

Witnesses and surveillance video indicated that the helicopter was flying northwest over the river when, about 1/2 mile from the takeoff location, it contacted…a static wire and a fiber optic line, which were the top two lines of an unmarked five-line array that crossed over the Fox River.

Wires over Fox River near Oshkosh, WI (Credit: NTSB)

Wires over Fox River near Oshkosh, WI (Credit: NTSB)

The lines were about 100 ft above the water and spanned about 640 ft across the river.

R44 N529DW Main Rotor Mast (Credit: NTSB)

R44 N529DW Main Rotor Mast (Credit: NTSB)

R44 N529DW Main Rotor Blade (Credit: NTSB)

R44 N529DW Main Rotor Blade (Credit: NTSB)

The tail rotor separated from the helicopter, and the helicopter subsequently impacted the river.

VIDEO on LinkedIn.  Witness testimony indicate the accident site was only about 500m from the location teh photographer was dropped off.

R44 N529DW Wreckage After Wirestrike (Credit: NTSB)

R44 N529DW Wreckage After Wirestrike (Credit: NTSB)

R44 N529DW Wreckage After Wirestrike (Credit: NTSB)

R44 N529DW Wreckage After Wirestrike (Credit: NTSB)

The NTSB report that the photographer commented…

…that they had flown over numerous bridges and power lines during the earlier flight and that they had discussed the location of the power lines in reference to the bridges.

The pilot had 559.6 total hours of flight experience, all in the R44.  The NTSB say:

The circumstances of the accident are consistent with the pilot flying at an unnecessarily low altitude and then failing to maintain clearance from the wires while flying at low level.

The helicopter was not fitted with any kind of wire strike protection system.  The NTSB do not discuss if the wires were marked on aeronautical chartes but it is unlikely they were.

Safety Resources

We have written on previous wirestrikes:

See also: Avoiding Wire Strikes

The European Safety Promotion Network – Rotorcraft (ESPN-R) has published this video and guidance with EASA:

easa wirestrike

Also see:

UPDATE 6 June 2020: Fish Spotting Helicopter Strikes Glassy Sea


Aerossurance has extensive air safety, operations, SAR, airworthiness, human factors, aviation regulation and safety analysis experience.  For practical aviation advice you can trust, contact us at: enquiries@aerossurance.com