killer: how an electronic assistant turned into a trap for helicopter pilots

The Boeing CH-47D helicopter, which was fighting a wildfire on the Salmon River on July 21, 2022, began to suddenly rotate to the left and fell into the water 13 seconds later. Video taken by eyewitnesses shows the helicopter continuing to spin counterclockwise until it crashed into the river.

At the scene, firefighters quickly pulled pilot Thomas Hayes, 41, and co-pilot Jared Byrd, 36, from the water, but both died of their injuries.

The National Transportation Safety Administration (NTSB) has yet to release a final crash report that would list the probable cause of the accident. However, in recent open file the case contains a “Examination Summary of the Model Helicopter and iPad,” which details how investigators identified the source of damage to the crew’s iPad, which was retrieved from the river with three distinct scratches and a kink from the back of the hull to the screen.

The Apple iPad and other so-called electronic flight bags (EFBs) have become common equipment in aircraft cockpits, used for flight planning, as an additional navigation aid, and as a replacement for paper documents, among other things.

NTSB investigators conducted their investigation using a model CH-47D helicopter with a cockpit configuration similar to that of the emergency helicopter. During the emergency flight, the pilot sat in the left seat and the co-pilot in the right.

Using auxiliary power to activate hydraulic assistance, investigators first pushed the pilot’s left pedal forward, which caused the co-pilot’s left pedal to move forward as well. (The left pedal is used to start yaw to the left and/or stop yaw to the right and vice versa.)

Investigators then placed the research iPad between the left pedal and the helicopter frame, next to the heel slide support assembly, on the co-pilot’s side. As the pressure on the pilot’s left pedal increased, the iPad fell and got stuck between the left pedal and the heel slide support assembly. This prevented the pedals from returning to center and also put pressure on the co-pilot’s left pedal adjustment lever.

When pressure was applied to the pilot’s right pedal, the iPad was compressed between the pedal and the heel slide support assembly. The scratches on the removed iPad were consistent with a sharp, vertical metal part of the build under the heel slip.

The extra pressure on the right pedal caused the iPad to put more pressure on the co-pilot’s pedal adjustment lever. Examination of the wreckage of the emergency helicopter revealed that the co-pilot’s left pedal was at the most forward setting and the right was at the middle setting.

According to investigators, the height of the co-pilot was 178 centimeters. During the study, with seat belts fastened and seats adjusted for comfort, neither the slightly smaller (170 cm) nor slightly larger (188 cm) person could reach the iPad in its stuck position.

Investigators also noted that the co-pilot’s flight helmet would have made any attempts to retrieve the iPad even more difficult, as the helmet would have collided with the visor above the dashboard.

Andy Evans, director of aviation security consultancy Aerossurance, said that while operators are usually required to conduct a risk assessment before implementing an EFB, there is often no explicit requirement to consider the risk of an EFB as a free object.

“Hopefully this crash will force operators to take a close look at all possible loose items in cabs and secure valuable tools and reference sources like the EFB,” he wrote to Vertical in an email.