History of Flight
On June 13, 2018, about 1205 Alaska daylight time, a wheel-equipped Cessna 207, registration N91038, and a wheel-equipped Cessna 175, registration N9423B, collided midair near the mouth of the Big Susitna River, about 20 miles west of Anchorage, Alaska. The Cessna 207 was operated by Spernak Airways, Inc., as a Title 14 Code of Federal Regulations Part 135 scheduled commuter flight. The Cessna 175 was registered to the pilot and operated as a Part 91 personal flight. Visual meteorological conditions prevailed, and both airplanes were operating under visual flight rules. The Cessna 175 departed a remote fish camp about 1126 en route to Lake Hood Seaplane Base (PALH); no flight plan was filed. The Cessna 207 departed Merrill Field (PAMR), Anchorage, about 1200, destined for Tyonek Airport (TYE), Tyonek, Alaska, with company flight following procedures in effect.
The pilot of the Cessna 175 stated that, while in level cruise flight about 1,000 ft mean sea level (msl), he was making position reports via radio and established contact with the pilot of a Piper Super Cub passing below him in the opposite direction. As he watched the Piper Super Cub pass well below his airplane, he noticed the shadow of an airplane from the opposite direction converging with the shadow of his airplane. He looked forward and saw the spinner of the converging airplane in his windscreen, and immediately pulled aft on the control yoke. The pilot stated that his airplane climbed abruptly just before the collision. After the collision, he observed the Cessna 207 descend uncontrolled into the river. He circled over the wreckage, marking the location and using his radio to enlist help. Realizing that no one had escaped the partially-sunken wreckage, he returned to PALH, escorted by a good Samaritan pilot who provided a damage report. Another good Samaritan pilot in a float-equipped airplane landed on the river and confirmed the Cessna 207 pilot was deceased.
A review of FAA radar data showed two unidentified targets, correlated to be the accident airplanes, converging from opposite directions about 1,000 ft msl. About one minute before the presumed accident time, the westbound target (believed to be the Cessna 207) descended to about 874 ft msl, then climbed to about 900 ft msl just before the targets appeared to merge. The eastbound target (Cessna 175) maintained about 1,000 ft msl throughout. After the merge, the eastbound airplane climbed, returned to the area, circled, then left.
Personnel Information
The Cessna 207 pilot, age 56, held a commercial pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane, and a flight instructor certificate for airplane single-engine. His most recent FAA third-class medical was issued on June 12, 2017, with no limitations. He was hired with 1,442 total flight hours, including 1,200 hours in Alaska and 514 hours in Cessna 207-series aircraft; at the time of the accident, he had accumulated about 767 additional hours in the accident airplane make and model. The pilot was off duty on June 10; on June 11 he flew 5.7 hours; on June 12, 4.8 hours; on the accident day, he flew 0.9 hour before the accident flight.
The Cessna 175 pilot, age 53, held a private pilot certificate for airplane single-engine land. His most recent FAA third-class medical was issued on February 20, 2017, with the limitation that he must wear corrective lenses. He reported 1,015 total flight hours, with about 315 hours in the accident airplane make and model.
Aircraft Information
Cessna 207, N91038, was manufactured in 1968, equipped with a Continental IO-520F engine (300 hp). The most recent 100-hour inspection was completed on May 6, 2018, at 31,711.5 airframe hours. The engine was overhauled on November 29, 2016, and had accumulated 766.6 hours since then.
Cessna 175, N9423B, was manufactured in 1958, equipped with a Lycoming O-360 A1A engine (180 hp). The most recent annual inspection was completed on December 13, 2017, at 5,296.29 airframe hours. The engine had accumulated 1,171.93 hours since the last annual.
Meteorological Information
The closest weather reporting facility was Anchorage International Airport (ANC), about 20 miles east of the accident site. At 1153, wind was from 290° at 5 knots; visibility 10 statute miles; few clouds at 4,500 ft, few at 10,000 ft, scattered at 20,000 ft; temperature 55°F; dew point 43°F; altimeter 29.91 inHg.
Wreckage and Impact Information
The Cessna 207 wreckage was inverted and partially submerged in the silty waters of the Big Susitna River; the left main tire and a portion of the fuselage protruded. After recovery, examination revealed the empennage separated from the aft fuselage; horizontal stabilizers and left elevator remained attached; right elevator bent upward; vertical stabilizer had accordion-style crushing. The main landing gear box separated; much of the cockpit, wings, engine, and propeller were not recovered.
The Cessna 175's left main gear leg and other debris were found about 1,380 ft east of the Cessna 207 wreckage. The left main gear and nosewheel were missing; the right main gear tire had a propeller strike; the right elevator outboard portion had impact damage with red paint transfer. The fuselage sustained impact damage just forward of the left main gear leg. Left and right wings, flaps, ailerons, and tail surfaces (except right elevator) were relatively undamaged.
Communications
The Cessna 175 pilot used a primary active frequency of 122.90 MHz and a non-active secondary frequency of 135.25 MHz. The transceivers from N91038 were not recovered. In May 2014, the FAA established geographic common traffic advisory frequency (CTAF) areas north and west of Anchorage; the accident area was at a frequency changeover point, with westbound Cook Inlet traffic on 122.70 MHz and eastbound on 122.90 MHz. Both airplanes were in Class G airspace, with no regulatory requirement for two-way radio communication.
Medical and Pathological Information
An autopsy of the Cessna 207 pilot attributed the cause of death to multiple blunt force injuries. Toxicology testing was negative for alcohol or drugs.