A near miss is a commonly used term for an event in which aircraft come dangerously close to a collision but no collision occurs. However, “near miss” is not a single, universally defined ICAO occurrence category, and more specific terminology is used in official aviation safety frameworks.
The FAA uses the term Near Midair Collision (NMAC) for certain situations involving a potential collision between aircraft. FAA guidance generally considers an NMAC to involve aircraft coming within 500 feet of each other, or a pilot or flight crew member reporting a collision hazard.
In international aviation, the term AIRPROX (aircraft proximity) may be used for situations in which the distance between aircraft, together with their relative positions and speeds, is considered to have potentially compromised safety. Depending on the circumstances and severity, a near-collision may also meet the criteria for a serious incident under ICAO Annex 13.
Therefore, “near miss” is best understood as a general safety term rather than a precise universal classification. Depending on the event, terms such as NMAC, AIRPROX, loss of separation, or serious incident may provide a more technically accurate description. These events may occur both on the ground and in the air and are triggered by various factors, including:
- Pilot error
- Air traffic controller error
- Mechanical failure
- Weather conditions
- System failures
- Examples of Near Misses
Here are a few examples of near misses in aviation:
On July 7, 2017, Air Canada Flight 759, an Airbus A320, was cleared to land on Runway 28R at San Francisco International Airport but mistakenly aligned with Taxiway C, where four aircraft were waiting for departure. The crew initiated a go-around at very low altitude, with the aircraft descending to approximately 60 feet above the ground. The incident became one of the most serious recent examples of a near-collision involving an arriving aircraft and aircraft on the ground.
On February 4, 2023, FedEx Flight 1432 was approaching Runway 18L at Austin-Bergstrom International Airport in dense fog while Southwest Flight 708 was cleared for takeoff on the same runway. The FedEx crew recognized the conflict and initiated a go-around, with the two aircraft coming within less than 200 feet of each other. The NTSB later determined that the controller had incorrectly assumed the Southwest aircraft would depart before the FedEx aircraft reached the runway.
On January 31, 2001, Japan Airlines Flights 907 and 958, carrying a combined total of more than 600 people, came dangerously close to colliding in the air over Japan following conflicting air traffic control instructions. The crew of Flight 907 made an abrupt evasive maneuver, and the aircraft passed within an estimated 135 meters (440 feet) of each other. Although a collision was avoided, around 100 people were injured during the maneuver.
Factors Contributing to Near Misses in Aviation
Near misses rarely result from a single error. They usually develop through a combination of human, operational, environmental, and technical factors that reduce safety margins or allow a conflict to develop.
| Contributing Factor | Examples |
|---|---|
| Flight Crew Factors | Loss of situational awareness, fatigue, miscommunication, navigation errors, or incorrect interpretation of ATC instructions |
| Air Traffic Control Factors | Incorrect clearances, coordination failures, high workload, distraction, or loss of situational awareness |
| Communication Issues | Readback/hearback errors, blocked transmissions, similar call signs, or ambiguous phraseology |
| Operational Factors | Traffic complexity, airspace constraints, unexpected aircraft maneuvers, or deviations from procedures |
| Weather & Environment | Poor visibility, thunderstorms, turbulence, wind, or other conditions affecting aircraft operations |
| Technical & System Factors | Navigation, communication, surveillance, or aircraft-system failures and degraded equipment |
The Swiss Cheese Model and Near Misses
The Swiss Cheese Model helps explain why near misses are often the result of several contributing factors rather than one isolated mistake. Aviation safety relies on multiple defensive layers—including procedures, training, ATC, technology, and collision-avoidance systems. Each layer may have weaknesses or “holes.” A dangerous situation can develop when weaknesses in several layers temporarily align, allowing a hazard to pass through the safety system.
Near-miss investigations are therefore important not simply for identifying who made an error, but for understanding how multiple safety barriers failed or became ineffective at the same time.
Prevention of Near Misses
To prevent near misses in aviation, we can do a number of things, such as…
- Improved pilot training: Pilots should be trained to identify and avoid potential hazards, and to respond quickly and appropriately to near misses.
- Improved air traffic control procedures: Air traffic controllers should be provided with the tools and resources they need to safely manage air traffic.
- Improved aircraft maintenance: Aircraft should be regularly maintained to prevent mechanical failures.
- Improved weather forecasting and reporting: Pilots and air traffic controllers should have access to accurate and up-to-date weather information.
- Improved aircraft safety systems: Aircraft should be equipped with safety systems that can help to prevent near misses, such as traffic collision and avoidance systems (TCAS).
Near misses in aviation are a serious safety concern. By understanding the causes of near misses and taking steps to prevent them, we can help to make aviation even safer.