N7511H

Substantial
Fatal

Piper PA-12-150S/N: 12-372

Accident Details

Date
Sunday, September 23, 2018
NTSB Number
ANC18FA071
Location
Healy, AK
Event ID
20180924X42217
Coordinates
63.900276, -147.733337
Aircraft Damage
Substantial
Highest Injury
Fatal
Fatalities
2
Serious Injuries
0
Minor Injuries
0
Uninjured
0
Total Aboard
2

Probable Cause and Findings

An impact with terrain for reasons that could not be determined based on the available information.

Aircraft Information

Registration
N7511H
Make
PIPER
Serial Number
12-372
Engine Type
Reciprocating
Year Built
1946
Model / ICAO
PA-12-150PA12
Aircraft Type
Fixed Wing Single Engine
No. of Engines
1

Registered Owner (Historical)

Name
SONNENBERG TIMOTHY M
Address
3230 COOL CACY DR
Status
Deregistered
City
FAIRBANKS
State / Zip Code
AK 99701-7808
Country
United States

Analysis

HISTORY OF FLIGHTOn September 22, 2018, the wreckage of a tailwheel-equipped Piper PA-12 airplane, N7511H, was located in remote mountainous terrain about 35 miles east of Healy, Alaska. The private pilot and the passenger were fatally injured, and the airplane was substantially damaged by impact forces and a postcrash fire. The airplane was registered to the pilot who was operating it as a Title 14 Code of Federal Regulations Part 91 personal flight. The flight departed from Fairbanks International Airport (FAI), Fairbanks, Alaska, on September 15, 2018, and no flight plan had been filed.

The purpose of the flight was to fly to the Alaska Range, which is a mountain range located about 50 miles south of Fairbanks, where the pilot and his passenger would hunt sheep. No communications from the pilot, such as from a satellite phone or a satellite communication device, were received by the family after the pilot's departure from FAI.

After the pilot did not report to his place of employment on September 19, a Federal Aviation Administration (FAA) alert notice "ALNOT" was issued at 1620 Alaska daylight time, and an extensive search and rescue (SAR) operation began the next day. The operation consisted of aerial SAR assets from multiple agencies, including the Alaska Air National Guard, the Alaska Army National Guard, the Civil Air Patrol, and the Alaska State Troopers, as well as several individual volunteers. The accident airplane was located by a volunteer, and an Alaska Army National Guard helicopter responded to the accident site and the aircrew found both occupants deceased inside of the wreckage. AIRCRAFT INFORMATIONThe airplane was equipped with a Garmin Aera GPS device, which was sent to the National Transportation Safety Board's (NTSB) Vehicle Recorder Division Laboratory in Washington, DC. The device is capable of storing data in nonvolatile memory. However, the circuit board was delaminated due to the thermal damage, and most of the components were burned off. The extent of the damage precluded recovery of the data.

The airplane was also equipped with an emergency locator transmitter (ELT), which did not broadcast after the accident. The ELT sustained postimpact fire damage, so the NTSB could not definitively determine why the ELT did not broadcast. METEOROLOGICAL INFORMATIONThe exact meteorological conditions before and at the time of the accident could not be determined. AIRPORT INFORMATIONThe airplane was equipped with a Garmin Aera GPS device, which was sent to the National Transportation Safety Board's (NTSB) Vehicle Recorder Division Laboratory in Washington, DC. The device is capable of storing data in nonvolatile memory. However, the circuit board was delaminated due to the thermal damage, and most of the components were burned off. The extent of the damage precluded recovery of the data.

The airplane was also equipped with an emergency locator transmitter (ELT), which did not broadcast after the accident. The ELT sustained postimpact fire damage, so the NTSB could not definitively determine why the ELT did not broadcast. WRECKAGE AND IMPACT INFORMATIONThe wreckage of the airplane was located in a remote snow-covered mountainous valley with rocks, alder trees, and a small creek. The wreckage was positioned on the east side of the creek on a heading of about 220° and at an elevation of about 4,300 ft mean sea level. Most of the wreckage showed evidence of a postimpact fire. The airplane came to rest upright, with the fuselage banking to the right, both wings indicating forward/aft crushing, and the tail slightly elevated with little impact damage.

All of the major structural components of the airframe were located at the accident site. An examination of the airframe revealed no pre-impact mechanical malfunctions or failures that would have precluded normal operation.

The engine was examined after the recovery of the wreckage. The examination revealed no pre-impact mechanical malfunctions or failures that would have precluded normal operation.

During examination, the AFT right wing spar exhibited signs of compression bending, with the right wing forward spar exhibiting aft bending. The AFT left wing spar bolt indicated a failure in tension, and the left wing forward spar indicated forward bending. MEDICAL AND PATHOLOGICAL INFORMATIONThe State of Alaska Medical Examiner's Office, Anchorage, Alaska, conducted an autopsy of the pilot. According to the autopsy report, the cause of death for the pilot was multiple blunt force injuries. The report also indicated that there was no evidence of soot-like material found in the pilot's airway.

Toxicology testing performed at the FAA Forensic Sciences Laboratory found that the pilot's specimens were negative for drugs and ethanol. SEARCH AND RESCUEThe FAA's Aeronautical Information Manual (AIM) discusses SAR operations and states in part the following: SAR is a lifesaving service provided through the combined efforts of the federal agencies' signatory to the National SAR Plan, and the agencies responsible for SAR within each state. Operational resources are provided by the U.S. Coast Guard, DOD [Department of Defense] components, the Civil Air Patrol, the Coast Guard Auxiliary, state, county and local law enforcement and other public safety agencies, and private volunteer organizations. Services include search for missing aircraft, survival aid, rescue, and emergency medical help for the occupants after an accident site is located.

Flight Plan

The AIM discusses the importance of filing a flight plan in case of an emergency or if an aircraft is overdue and states in part the following:

A filed flight plan is the most timely and effective indicator that an aircraft is overdue. Flight plan information is invaluable to SAR forces for search planning and executing search efforts.

Prior to departure on every flight, local or otherwise, someone at the departure point should be advised of your destination and the route of flight if other than direct. Search efforts are often wasted, and rescue is often delayed because of pilots who thoughtlessly take off without telling anyone where they are going. File a flight plan for your safety.

Data Source

Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ANC18FA071