It took rescuers about nine hours to find a plane that crashed into a steep mountainside in the Eagle River Valley in July 2021 because the emergency locator did not activate, federal investigators say.
The crash killed 23-year-old flight instructor Dakota Bauder and 27-year-old pilot McKenna Vierra.
It’s unclear if an earlier response would have saved either Bauder or Vierra, but Bauder’s Apple Watch detected a pulse up to two hours after the plane was believed to have crashed, according to a National Transportation Safety Board final report released last week.
Bauder was an instructor with Angel Aviation Flight School and had gone out with Vierra on a “discovery” or introductory flight in the Chugach Mountains on July 26, 2021, according to investigators. Messages left for Angel Aviation were not returned on Monday.
Vierra was visiting Alaska from her home in Hawaii to celebrate her boyfriend’s birthday, her family has said. She was a flight attendant with Hawaiian Airlines and had recently earned her private pilot’s license, studying for flight exams as she underwent chemotherapy treatments for lymphoma. A month after she earned her license, the once softball-sized tumor near her heart was no longer detectable.
Vierra wanted to log flight time during her Alaska trip because she was working toward becoming a commercial pilot, her family said.
She and Bauder left Merrill Field in a Cessna 172P around 12:15, the NTSB report said. The plane crashed into a steep mountain in Eagle River Valley about an hour later, according to the report.
The report doesn’t make it clear what caused the plane to crash: investigators did not find enough physical evidence to determine that during their nearly two-year examination of the crash, said Clint Johnson, head of the NTSB’s Alaska office.
Carburetor icing may have been a factor, but that’s a common thing for pilots to encounter and Bauder was likely monitoring the risk of icing and taking steps to mitigate it, Johnson said.
The emergency locator transmitter installed on the plane failed to send an alert on impact, the report said. The model had been flagged by the Federal Aviation Administration in 2015 after multiple reports that it failed to send emergency signals as needed. The equipment was required to undergo annual testing, according to an airworthiness directive issued by the FAA in 2017.
A mechanic wrote in the maintenance records kept for the plane that the transmitter had been replaced with a different make and model about a year and a half before the crash, but NTSB investigators discovered the equipment had never actually been changed out, according to the final report. The mechanic again inspected the aircraft six months before the crash and wrote that the transmitter had been tested, the report said.
A family member notified authorities that the plane was overdue when Bauder and Vierra had not returned by 2 p.m., the report said. The wreckage was located “in an area of steep, rising glacial terrain at an elevation of about 3,100 feet” in Eagle River Valley around 10:45 p.m., it said.
Bauder and Vierra were dead when the plane was located.
“Had the ELT (emergency locator transmitter) functioned as designed, emergency personnel would have been alerted to the accident, even if the company did not report it overdue,” investigators wrote in the report. “Similarly, had the AD-affected ELT been removed and replaced with a functional unit as was noted in the maintenance records, the search and rescue response likely would have been faster; however, whether faster location of the wreckage would have prevented a fatal outcome could not be determined.”