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Accidents · NTSB ANC11FA062 · Final report

Cessna U206 and Piper PA-31-350 mid-air collision near Port Alsworth, Alaska, July 10, 2011

On July 10, 2011 at about 9:15 pm local time, 2 aircraft, Cessna U206 (N2186F) and Piper PA-31-350 (N76RA), were involved in a mid-air collision near Port Alsworth, Alaska. No one was hurt; 13 people were on board or involved. The weather was visual conditions (good weather).

The NTSB's probable cause their words, unchanged

The pilot’s failure to see and avoid the approaching airplane, which did not have any forward-facing lights.
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.

Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.

What the record shows

Date
July 10, 2011 · about 9:15 pm local time · cases in 2011
Place
Port Alsworth, Alaska · map
Type
Accident · mid-air collision
Injuries
No one was hurt; 13 people were on board or involved.
Weather
visual conditions (good weather)
Aircraft 1
Cessna U206 · all U206s on the register
Registration
N2186F · registry record · serial U2060386
Damage
Minor damage
Flight
Personal flight · general aviation rules (Part 91)
Aircraft 2
Piper PA-31-350 · all PA-31-350s on the register
Registration
N76RA · registry record · serial 31-7752089
Damage
Substantial damage
Flight
Flight · charter and air-taxi rules (Part 135)

The NTSB's narrative for the Cessna U206 final · quoted from the NTSB record

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 complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The NTSB's narrative for the Piper PA-31-350 final · quoted from the NTSB record

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 complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.

The factual record for the Cessna U206 from the NTSB's investigation tables, in plain English

What happened, in order

  1. Midair collision during enroute (cruise) defining event

The NTSB's findings

  • Environmental issues › Operating environment › Air traffic/operating proc › Traffic congestion › Contributed to outcome
  • cause Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Pilot

Pilot

  • Certificate: airline transport pilot
  • Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
  • Flight time: 29,000 hours in all; 1,500 in this make and model; 90 in the last 90 days; 60 in the last 30 days; 27,500 as pilot in command
  • Last flight review: May 16, 2011
  • Medical certificate: Class 1 (with waivers/limitations)
  • Seat: left
  • Injury: no injuries

The aircraft

  • Last inspection: annual inspection
  • Maximum gross weight: 3,300 lb
  • Seats: 6
  • Landing gear: retractable
  • Engine: Cont Motor IO 520 SERIES (piston); 0 hours total

The flight

  • Departed from: LHD Anchorage AK at 3:10 pm
  • Destination: Brooks Camp AK
  • Flight plan: VFR

Weather at the time

  • Light: daylight
  • Visibility: 10 statute miles
  • Sky: overcast at 4,000 ft; clear
  • Temperature: 50°F (10°C), dew point 0°F (-18°C)
  • Altimeter: 30.11 inHg

Injuries

FatalSeriousMinorNone
Flight crew1
Passengers3

The factual record for the Piper PA-31-350 from the NTSB's investigation tables, in plain English

What happened, in order

  1. Midair collision during enroute (cruise) defining event

The NTSB's findings

  • factor Aircraft › Aircraft systems › Lighting system › Exterior lighting › Design other cases naming the electrical power
  • factor Personnel issues › Task performance › Communication (personnel) › Lack of communication › Pilot
  • Environmental issues › Operating environment › Air traffic/operating proc › Traffic congestion › Contributed to outcome
  • cause Personnel issues › Psychological › Attention/monitoring › Monitoring other aircraft › Pilot

Pilot

  • Certificate: airline transport pilot
  • Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
  • Flight time: 19,719 hours in all; 6,500 in this make and model; 189 in the last 90 days; 89 in the last 30 days; 19,719 as pilot in command
  • Last flight review: March 29, 2011
  • Medical certificate: Class 2 (without waivers/limitations)
  • Seat: left
  • Injury: no injuries

The aircraft

  • Airframe total time: 12,311 hours
  • Last inspection: approved inspection programme, June 27, 2011
  • Maximum gross weight: 7,368 lb
  • Seats: 8
  • Landing gear: retractable
  • Engine 1: Lycoming TIO-540 SER (piston); 0 hours total
  • Engine 2: Lycoming TIO-540 SER (piston); 0 hours total
  • Operator: Lake Clark Air INC

The flight

  • Departed from: 9K2 Kokhanok AK at 3:54 pm
  • Destination: MRI Anchorage AK

Injuries

FatalSeriousMinorNone
Flight crew1
Passengers8

Documents from the investigation the NTSB's docket: the evidence folder behind the report

The NTSB has not released the docket for this case yet. The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), is usually released when the investigation is nearly complete, and the list here is refreshed when it appears. Check at the NTSB.

Connections how this case links to the rest of the register

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The whole map of how records connect · these connections as data: /graph/accident/ANC11FA062.json.

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Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.