It took three days for scores of rescuers and volunteers to reach the missing PA-18 Super Cub that crashed June 24, killing Art and Ann Ward of Salcha.
A new report from the National Transportation Safety Board says the plane's emergency locator beacon was never turned on.
Art Ward, 63, was a pilot and game guide in the Brooks Range and described as being well known in Alaska hunting and aviation circles. His wife, Ann, 59, was the only other person on the plane.
The couple took off from a private airstrip near Salcha just before 10:30 a.m. that Sunday, headed for their homestead west of McCarthy. A relative reported them overdue the next day.
An intense air search involved multiple parties including the Rescue Coordination Center, Alaska Air National Guard, Civil Air Patrol, U.S. Marine Corps, National Park Service and several McCarthy-area air taxi and lodge airplanes.
The plane was found about 30 miles southwest of Fort Greeley four days after the crash by an Alaska Army National Guard Black Hawk helicopter on a site survey training mission.
The plane carried a "legacy" emergency locator transmitter instead of a newer digital unit that instantly transmits a distress signal to search-and-rescue satellites, according to a preliminary report the NTSB released Tuesday.
But the type of locator on the plane didn't matter because it was found in the "off" position, lead investigator Shaun Williams said in an interview.
"No signal was broadcasting," Williams said.
It wasn't clear why Ward didn't turn on the locator, he said. "That's something that we're looking into right now."
Had the unit been turned on, the Rescue Coordination Center would probably have picked up a signal on the first day of the search.
Weather at the closest reporting site — 22 miles northeast of the crash — included winds around 10 mph, 10-mile visibility, light rain and a broken cloud ceiling at 6,000 feet, according to the report.
But weather data in the area is "sparse," Williams said. He's hoping to talk with pilots who were flying around Isabel Pass on June 24.
Williams can be reached with weather information at 907-782-4849.
Investigators will conduct a detailed examination of the wreckage. The plane was equipped with a Lycoming O-320 series engine, according to the report.