Authorities on Wednesday halted efforts to recover a plane that crashed into a snow-covered glacier in Wrangell-St. Elias National Park and Preserve in late August, killing two people on board.
Clayton McMartin, 59, and his wife, 58-year-old Melissa McMartin from Roanoke, Texas, died in the crash, the National Park Service said.
Officials called off the recovery effort as the National Transportation Safety Board on Wednesday released a preliminary report that details the minutes leading up to the crash, when the pilot lost communication with air traffic control in an area where poor weather was expected.
The couple departed Glennallen in a Beechcraft Bonanza B-36 headed toward Ketchikan around 8:50 a.m. Aug. 27, according to the preliminary report.
NTSB investigators reviewed air traffic communications from the Federal Aviation Administration and broadcast data from the flight to piece together what happened leading up to the collision. Because of the mountainous terrain, radio communication was limited in some areas, said Clint Johnson, chief of the NTSB’s Alaska office.
The report detailed conversations with the Anchorage Air Route Traffic Control Center in which the pilot confirmed the plane would climb to a higher elevation. Clayton McMartin told the controller “he knew he had some weather ahead of him,” the report said.
There were no official aviation weather reports issued within 100 miles of the remote crash site. A Federal Aviation Administration weather camera roughly 18 miles away, and pointed away from the crash, showed low clouds that obscured higher terrain and had a visibility of less than 3 miles, the NTSB preliminary report said.
As the plane climbed, the controller and pilot lost radio communication for a few minutes, the report said. Once they reestablished radio contact, the controller told the pilot that communications would drop again for about 10 minutes, according to the report.
The controller was unable to reach the pilot about 10 minutes later and asked another nearby pilot to relay instructions to Clayton McMartin, to turn 20 degrees to the right to avoid any higher terrain, the report said. It’s standard practice to have others nearby relay instructions when pilots can’t be reached by air traffic controllers, Johnson said.
The message was relayed to McMartin, who acknowledged the instructions, the report said.
He reestablished radio contact with the air traffic controller and was approved to then climb to 15,000 feet, the report said. Five minutes later, the controller was unable to reach the pilot again, and noted that the plane was “rapidly descending at 11,000,” the report said.
Archived data from the flight showed it had reached 14,950 feet, then began a left turn and rapid descent, the NTSB said in its preliminary report.
Poor weather conditions prevented rescuers from immediately reaching the area where the plane was last known to be located. A U.S. Coast Guard crew located the wreckage on Aug. 28 near Mount Leeper in the southern portion of Wrangell-St. Elias National Park. The area is roughly 18 miles inland from Cape Yakataga, on the Gulf of Alaska.
The National Park Service said Sept. 2 that responders’ efforts had shifted from rescue to recovery because of the amount of time that had passed since the crash and the continued poor weather. Johnson said at the time that it was unlikely the McMartins could have survived the crash.
A park ranger flew over the area Sept. 5 during a break in the weather and photographed and analyzed the wreckage site, the park service said Wednesday. According to the NTSB preliminary report, a large portion of the plane was located in a snow crater. The plane fragments were in a highly crevassed part of the Yahtse Glacier where snow continually accumulates — “making the wreckage permanently inaccessible,” the park service said.
Wrangell-St. Elias officials on Wednesday called off efforts to recover the wreckage and the plane’s occupants. The NTSB, troopers and park rangers determined the extreme terrain and challenging weather would make it unsafe for rescuers to reach the crash site, the park service said.
The NTSB will continue investigating what caused the plane to lose control and rapidly descend into the mountain, Johnson said.
“Obviously, we’re going to be hindered with not being able to see the wreckage and be able to take a look at it from a mechanical standpoint,” he said. “However, there’s still a lot of information that we can use.”
The findings of the final investigation will likely be released in about a year, Johnson said.