Saturday, June 23, 2018

Aeronca 15AC, N1370H: Fatal accident occurred July 15, 2017 in Big Lake, Alaska

Donald Wayne Frantz passed away on July 15, 2017, along the Yentna River, Alaska.  

Don bought his first airplane, an Aeronca Sedan, in 1975. The next year he began guiding for big game. His love for guiding continued until the mid '80s. 

In 2010, Don took up another project. He started to build his second airplane at the Legend Cub Factory in Sulphur Springs, Texas. It took him six months to finish the plane. After the completion of his airplane, he flew it up to Alaska. The journey home took eight days.

The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Anchorage, Alaska
Lycoming

Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf


Investigation Docket - National Transportation Safety Board:
http://registry.faa.gov/N1370H 

Analysis 

The pilot was shuttling friends to his remote recreational cabin in the airplane, and the accident occurred during the return trip after dropping off the first group of friends. When the airplane failed to arrive to pick up the second group of friends, a family friend initiated an aerial search and found the wreckage.

The accident site was located about 600 ft from a river that the pilot reportedly often flew along at low altitude during his return flights from his remote cabin. The airplane initially impacted the top of an estimated 45-ft-tall tree located about 150 ft from the river bank. After the initial impact, the airplane traveled about 450 ft before coming to rest inverted. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

Given the lack of mechanical deficiencies with the airplane, the elliptical impact areas to the airplane's severed left wing, and the pilot's habit of flying low level along the river, it is likely that the pilot inadvertently collided with a tree while in cruise flight at low-altitude.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilot's failure to maintain clearance from trees during low-altitude flight, which resulted in an in-flight collision and impact with terrain.

Findings

Aircraft
Altitude - Not attained/maintained (Cause)

Personnel issues

Monitoring environment - Pilot (Cause)

Location:BIG LAKE, AK 
Accident Number: ANC17FA035
Date & Time: 07/15/2017, 0925 AKD
Registration: N1370H
Aircraft: AERONCA 15AC
Aircraft Damage: Substantial
Defining Event: Low altitude operation/event
Injuries: 1 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal

HISTORY OF FLIGHT

On July 15, 2017, about 0925 Alaska daylight time, a float-equipped Aeronca 15AC airplane, N1370H, sustained substantial damage following a collision with a tree and impact with terrain about 20 miles west of Big Lake, Alaska. The commercial pilot sustained fatal injuries. The airplane was registered to and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions existed, and no flight plan had been filed. The flight departed a remote lake near Big Lake about 0905 destined for Sand Lake, Anchorage, Alaska.

According to a family friend, the purpose of the flight was to shuttle several friends from Sand Lake to the pilot's remote recreational cabin. The pilot dropped off the first group of friends and was returning to Sand Lake when the accident occurred. When the airplane failed to arrive at Sand Lake to shuttle the second group of friends, the family friend initiated an aerial search and ultimately found the accident site. The family friend also stated that the pilot liked to fly at a low level over the Yetna River to look for eagle's nests when returning from his recreational cabin.

Another family friend said that it was common for the pilot, when returning from his recreational cabin, to fly between 300 and 500 ft above ground level (agl) over the Yetna River to the confluence of the Yetna and Big Susitna Rivers. He would then climb to about 1,100 feet agl for the remainder of the trip to Sand Lake.

PERSONNEL INFORMATION

The pilot, age 75, held a commercial pilot certificate with ratings for airplane single-engine land and sea and instrument airplane. On May 24, 2017, the pilot applied for "BasicMed,"an alternative to third-class medical certification to fly certain small aircraft, including the accident airplane.

Some personal flight records were located for the pilot; however, they were not complete. On his most recent application for a medical certificate, dated June 7, 2013, he indicated that his total aeronautical experience was about 5,892 hours of which 38 hours were in the previous 6 months.

AIRCRAFT INFORMATION

The airplane was manufactured in 1949. A review of the maintenance records revealed that the most recent annual inspection was completed on September 9, 2016, when the airframe had accumulated 4,659.6 hours total time in service.

The airplane was equipped with a Lycoming O-360 engine rated at 180 horsepower at 2,700 rpm. The engine was last overhauled on June 28, 2005 and had accumulated 874.6 hours since overhaul at the most recent annual inspection.

METEOROLOGICAL INFORMATION

The closest weather observation station to the accident site was Wasilla Airport, Wasilla, Alaska, located about 31 miles east of the accident site. At 0856, Wasilla was reporting, in part, wind calm, visibility 10 statute miles, clouds and ceiling 4,600 ft broken, 6,000 ft overcast, temperature 60°F, dewpoint 51°F, and altimeter 30.01 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The accident site was located in an area of brush- and tundra-covered terrain with scattered trees at an elevation of about 50 ft. The initial impact point was marked by a broken tree top, atop an estimated 45-foot-tall cottonwood tree, located about 150 ft from the west bank of the Yetna River. Broken tree branches and paint fragments that matched the color of the airplane were located below the initial impact point. The main wreckage was located northeast along a magnetic heading of about 072° about 450 ft from the initial impact point. The fuselage came to rest inverted. All of the airplane's major components, with the exception of the left wing, were found at the main wreckage site.

The severed left wing was located about 160 ft from the initial impact point. A large elliptical impact area was found on the leading edge, about 3 ft outboard of the wing root, with multiple smaller elliptical impact areas outboard to the tip. The left aileron remained attached to its respective attach points and was relatively undamaged.

The right wing separated about 3 inches inboard of its rear attach point but remained attached to the fuselage at its forward attach point. Multiple elliptical impact areas were found on the leading edge. The wing's lift strut remained attached at both the fuselage and wing attach points. The right aileron remained attached to its respective attach points but sustained impact damage.

The cockpit area was extensively damaged. The engine, firewall, and instrument panel were displaced upward and aft. The throttle control was found in the near full-forward position, and the carburetor heat was in the off position. The horizontal and vertical stabilizer, elevators, and rudder remained attached to the empennage and were relatively free of impact damage.

All the primary flight control surfaces were identified at the accident site, and flight control continuity was verified from the cockpit to the elevators and rudder. Aileron control continuity was established from the control column to the overhead aileron bell crank, in the aileron control cables to the wing aileron bell cranks, and in the aileron push-pull tubes. A fracture was observed in the left aileron bell crank; multiple fractures were observed in the overhead aileron bell crank; all fractures were consistent with overload.

The engine was examined on August 16, 2017. The engine sustained impact damage to the front, top and underside. No anomalies, contamination, or evidence of malfunction was found in any of the engine accessories. The cylinders, pistons, valve train, crankshaft, and other internal components were all without evidence of anomaly or malfunction. Both magnetos were removed from the engine. When the magneto couplings were rotated, blue sparks were observed at the distributor in rotational order.

The propeller remained attached to the engine crankshaft by its attach bolts. Both propeller blades exhibited slight torsional "S" twisting and aft bending.

The examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

MEDICAL AND PATHOLOGICAL INFORMATION

The Alaska State Medical Examiner, Anchorage, Alaska conducted an autopsy of the pilot. The cause of death for the pilot was attributed to multiple blunt force injuries.

The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on specimens from the pilot, which were negative for carbon monoxide and ethanol. The toxicology testing revealed 0.039 ug/ml of morphine in the pilot's urine.

Morphine is a prescription narcotic used for the treatment of moderate to severe pain. The cutoff for federal workplace testing of urine is 2.000 ug/ml. The level of morphine detected in the pilot's urine was well below this level, and the medication was not detected in his blood. 

Pilot Information

Certificate: Commercial
Age: 75, Male
Airplane Rating(s): Single-engine Land; Single-engine Sea
Seat Occupied: Left
Other Aircraft Rating(s): None
Restraint Used: 3-point
Instrument Rating(s): Airplane
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: Yes
Medical Certification: BasicMed Unknown
Last FAA Medical Exam: 05/24/2017
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time: (Estimated) 5892 hours (Total, all aircraft) 

Aircraft and Owner/Operator Information

Aircraft Manufacturer: AERONCA
Registration: N1370H
Model/Series: 15AC
Aircraft Category: Airplane
Year of Manufacture: 1949
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 15AC-419
Landing Gear Type: Float;
Seats: 
Date/Type of Last Inspection: 09/09/2016, Annual
Certified Max Gross Wt.:
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 4659.6 Hours as of last inspection
Engine Manufacturer: LYCOMING
ELT: C91  installed, not activated
Engine Model/Series: O-360
Registered Owner: On file
Rated Power: 180 hp
Operator: On file
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: PAWS
Observation Time: 1656 UTC
Distance from Accident Site: 31 Nautical Miles
Direction from Accident Site:
Lowest Cloud Condition:
Temperature/Dew Point: 16°C / 11°C
Lowest Ceiling: Broken / 4700 ft agl
Visibility:  10 Miles
Wind Speed/Gusts, Direction: Calm
Visibility (RVR):
Altimeter Setting: 30.01 inches Hg
Visibility (RVV):
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: BIG LAKE, AK
Type of Flight Plan Filed: None
Destination: Anchorage, AK
Type of Clearance: None
Departure Time:  AKD
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude:  61.606389, -150.506667 (est)

NTSB Identification: ANC17FA035
14 CFR Part 91: General Aviation
Accident occurred Saturday, July 15, 2017 in BIG LAKE, AK
Aircraft: AERONCA 15AC, registration: N1370H
Injuries: 1 Fatal.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

On July 15, 2017, about 0925 Alaska daylight time, a float-equipped Aeronca 15AC airplane, N1370H, sustained substantial damage following a collision with a tree, and a subsequent loss of control and impact with terrain, about 20 miles west of Big Lake, Alaska. The commercial pilot, the sole occupant, sustained fatal injuries. The airplane was registered to and operated by the pilot, as a 14 Code of Federal Regulations Part 91 visual flight rules flight. Visual meteorological conditions existed, and no flight plan had been filed. The flight departed a remote lake near Big Lake, Alaska about 0905 destined for Sand Lake, Anchorage, Alaska.

According to a family friend, the purpose of the flight was to shuttle a group of friends to a remote recreational cabin and the accident occurred during the return trip to Sand Lake. When the airplane failed to arrive at Sand Lake to shuttle the second group of friends, another family friend initiated an aerial search, and ultimately found the accident site. 

The National Transportation Safety Board (NTSB) investigator-in-charge (IIC) along with another NTSB investigator and an Alaska State Trooper reached the accident site in the afternoon of July 16. The accident site was in an area of tall brush and tundra covered terrain with sparsely populated trees at an elevation of about 50 ft msl. An area believed to be the initial impact point was marked by a broken tree top, atop about a 45-foot-tall cottonwood tree, situated near the banks of the Yentna River. Broken tree branches and paint fragments that matched the color of the airplane were located at the base of the cottonwood tree. After the initial impact, the airplane's wreckage traveled northeast along a magnetic heading of about 072° for about 450 ft before coming to rest inverted. 

The airplane's severed left wing was located about 160 ft from the 45-foot-tall cottonwood tree, initial impact point. A large elliptical impact area was found on the leading edge, about 3 ft outboard of the wing root, with multiple smaller elliptical impact areas outboard to the tip. 

All the primary flight control surfaces were identified at the accident site, and flight control continuity was verified from the cockpit to the elevators and rudder. Aileron control continuity was established from the control column in the aileron control cables to the fuselage aileron bell crank, in the aileron control cables to the wing aileron bell cranks and in the aileron push-pull tubes. A fracture was observed in the left aileron bell crank and multiple fractures were observed in the fuselage aileron bell crank, but all fractures were consistent with overload. A detailed wreckage examination is pending following recovery of the airplane. 

1 comment: