NTSB Identification: ANC11FA062B
Nonscheduled 14 CFR Part 135: Air Taxi & Commuter
Accident occurred Sunday, July 10, 2011 in Port Alsworth, AK
Probable Cause Approval Date: 07/18/2012
Aircraft: PIPER PA-31-350, registration: N76RA
Injuries: 13 Uninjured.

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.

Two airplanes, a Cessna and a Piper, collided midair in a mountain pass while traveling in opposite directions. The pass is a river valley, about 1/2-mile wide, with the floor about 1,000 feet mean sea level (msl), between mountains in excess of 5,000 feet msl. Neither pilot saw the other airplane in time to take evasive action. Both airplanes landed safely after the collision. The airplanes were operating in visual flight rules meteorological conditions, in uncontrolled airspace at about 2,300 feet msl, without any air traffic control services. The westbound Cessna sustained minor damage to its left float and the eastbound Piper sustained substantial damage to its vertical stabilizer and rudder.

The Cessna pilot reported that he was monitoring the common traffic advisory frequency (CTAF) for the pass and making position reports. He saw the opposing airplane pass under his left front and heard a loud “thump.” The Cessna was equipped with wingtip- and tail-mounted strobe anticollision lights, which were operating at the time of collision.

The Piper pilot reported that when he spotted the Cessna floatplane he did not have time to take evasive action. He was not monitoring the CTAF, and the airplane he was flying had no anticollision wingtip strobes or any forward-facing lights.

A local Federal Aviation Administration publication contains a graphic representation of the pass, and includes remote communications outlets, weather cameras, reference points, and a CTAF for the pass.

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

The pilot’s failure to see and avoid the approaching airplane. Contributing to the accident was that the pilot’s failure to listen to radio position reports from the other airplane on the common traffic advisory frequency and the absence of any forward-facing lights on his airplane.

Full narrative available

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