Boeing 777 - 236 incident near Shemya, Alaska, August 16, 2014
On August 16, 2014 at about 5:35 am local time, a Boeing 777 - 236, registered N773AN, was involved in an incident during enroute (change of cruise level) near Shemya, Alaska. It was flown under scheduled airline rules (Part 121). The NTSB record does not give the injuries. The weather was conditions the NTSB did not record.
The NTSB's probable cause their words, unchanged
The air traffic controller’s failure to identify a conflict between two aircraft and to issue an adequate clearance, which resulted in a loss of required separation. Contributing to the incident was the Federal Aviation Administration’s failure to provide controllers adequate automated conflict detection assistance, which removed a layer of backup to controller judgment and reduced the overall level of safety.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 16, 2014 · about 5:35 am local time
- Place
- Shemya, Alaska · map
- Type
- Incident
- Injuries
- The NTSB record does not give the injuries.
- Weather
- conditions the NTSB did not record
- Aircraft
- Boeing 777 - 236 236 · all 777 - 236s on the register
- Registration
- N773AN · registry record · serial 00000
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
A loss of required separation occurred near Shemya, Alaska, between a Boeing 777-200 en route to Shanghai Pudong International Airport, Shanghai, China, and a Boeing 747-400 en route to Ted Stevens Anchorage International Airport, Anchorage, Alaska. There was no damage to either aircraft, and no injuries were sustained by the passengers or crewmembers. The flight crew of the Boeing 777 requested to climb from flight level (FL) 360 to FL 370. Given the Boeing 777's position at the time, the requested climb would have conflicted with two other airplanes that were traveling at FL 370 but in the opposite direction. The air traffic controller identified the potential conflict between the Boeing 777 and the first airplane, but he did not identify the conflict between the Boeing 777 and the second airplane, the Boeing 747. The controller instructed the flight crew of the Boeing 777 to remain at FL 360 until they passed the first airplane and then to climb to FL 370. The flight crew of the Boeing 777 acknowledged and complied with the clearance, which resulted in a loss of required separation with the Boeing 747. Both flight crews received and responded to resolution advisories from their onboard traffic alert and collision avoidance systems after the controller issued the climb clearance. The Federal Aviation Administration (FAA) estimated that the minimum separation between the two aircraft was 1.04 miles laterally and 900 ft vertically. Typically, two types of automated conflict detection were available to controllers in the Shemya radar coverage area: a "conflict probe" that provided controllers with extended warning time for future conflicts and a short-term conflict alert system that looked about 2 minutes ahead to detect conflicts between radar-observed aircraft. However, the FAA had intentionally disabled the extended conflict probe in the Shemya radar coverage area because of unresolved performance issues, and the only automated conflict detection assistance available to the controllers in this area was the short-term conflict alert system; this removed a layer of backup to controller judgment and reduced the overall safety of flight operations in this area. Postincident corrective actions resulted in the extended conflict probe being returned to service. If the extended conflict probe had been available at the time of the incident, it is likely that it would have detected the conflict and alerted the controller about it before he issued the incorrect clearance and that no loss of separation would have occurred.
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 from the NTSB's investigation tables, in plain English
What happened, in order
- Air traffic event during enroute (change of cruise level)
- Near midair/TCAS alert/loss of separation during enroute (change of cruise level) defining event
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Identification/recognition › ATC personnel
- factor Organizational issues › Development › Design › Interface design › ATC
- factor Organizational issues › Management › Resources › Availability of equipment › FAA/Regulator
The aircraft
- Landing gear: fixed
The flight
- Departed from: Shemya AK
- Destination: Shemya AK
Weather at the time
- Light: night
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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 never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.