Two men have died after a small aircraft flying from Penticton, British Columbia, to Grangeville, Idaho, crashed in eastern Washington12. Search and rescue teams from the Washington State Department of Transportation (WSDOT) found the wreckage of the 1976 Piper Cub in the Aeneas Valley near Tonasket on Sunday 11 October, a day after the aircraft went missing34. WSDOT said the pilot, 61-year-old Nicholas Grachanin, and his passenger were found deceased inside the aircraft3. The Idaho County Free Press, which gives the same name and age for the pilot, reported that he was from Kooskia, Idaho1. WSDOT has not said what caused the crash1.

A flight that lost contact

The aircraft left Penticton on Saturday 10 October, bound for Grangeville3. According to WSDOT, the pilot and a passenger were aboard when the pilot lost communication with Seattle Center air traffic control4. The pilot's daughter then contacted the Okanogan County Sheriff's Office to report the aircraft and its occupants missing, and WSDOT Air Search and Rescue was notified on Saturday evening4. Castanet, a news site in the Okanagan region of British Columbia, carried the same account from WSDOT's statements2. Before the wreckage was found, the sheriff's office had identified the two men only by their first names, James and Nicholas, KIVI-TV reported5.

WSDOT has not published the aircraft's registration or its exact Piper model34. Source ONE News reported that no information was immediately available about what caused the accident6. Nothing in the official statements so far points to a cause, and questions about it are being referred to federal investigators3.

How the search unfolded

WSDOT teams started with the aircraft's last known radar locations between Oroville and Okanogan, and used mobile phone forensics to help identify potential search areas4. Ground search resources from the Colville Confederated Tribes were also called in4. WSDOT said no distress signals were received overnight, and that air search operations would continue on Sunday "with favorable weather conditions"4. As the search went on, the areas of interest were widened to include the Aeneas Valley, Wauconda and the surrounding mountainous terrain7. The sheriff's office warned residents to expect increased air traffic, asked them not to fly drones near the search areas and advised the public not to carry out independent air or ground searches5.

The wreckage and the two occupants were located at approximately 4:30 pm on Sunday, and the families were notified3. Agencies that took part included the Okanogan County Sheriff's Office, Okanogan County Emergency Management, the Snohomish County Sheriff's Office air support unit, the Confederated Tribes of the Colville Reservation and WSDOT personnel3. The Omak-Okanogan County Chronicle also lists the Civil Air Patrol among the agencies involved7. "On behalf of the search and rescue team, WSDOT extends our sincere condolences to the families and loved ones of those who lost their lives," said Tom Peterson, WSDOT's Air Search and Rescue Coordinator and Incident Commander3.

In Washington, the coordination and management of aerial search and rescue is a statutory task of WSDOT, under RCW 47.68.3803. In its final update on Sunday evening, the agency said this concluded its involvement in the mission and that further information would be released by the Okanogan County Sheriff's Office8.

What the investigation involves

WSDOT directs media questions about any investigation of the cause to the National Transportation Safety Board (NTSB)3. The Omak-Okanogan County Chronicle reports that the cause is under investigation by the NTSB7. The board's investigations go through the same general phases: notification and the decision to investigate, on-site fact gathering, analysis and determination of probable cause, and acceptance of a final report9. Fact gathering is not limited to the accident site and can include flight logs, maintenance records and interviews9. The NTSB says it generally tries to complete an investigation within 12 to 24 months, depending on complexity and workload9.

What this means for pilots

For anyone learning to fly, the search is a reminder of how emergency locator transmitters (ELTs) work, although it is not known whether this aircraft carried one or what type. The FAA's Aeronautical Information Manual says ELTs are required for most general aviation aeroplanes and transmit on 121.5 MHz, 243.0 MHz or the newer 406 MHz10. Since 2009 the Cospas-Sarsat satellite system no longer monitors 121.5 and 243.0 MHz, so aircraft with only those older ELTs depend on a nearby air traffic facility or an overflying aircraft to pick up the signal10. A properly registered 406 MHz ELT, by contrast, is detected by satellite and its owner information is passed to a rescue coordination centre10.

The manual also asks pilots and passengers to know how to activate the ELT manually and to be able to check that it is transmitting after a crash or manual activation10. Pilots are encouraged to monitor 121.5 MHz in flight and to report any emergency signal they hear to the nearest air traffic facility10. For those at the start of training, the route to a first licence is set out in PPL costs, duration and requirements.