How is a near miss defined?

Magnetoz
  • How is a near miss defined? Magnetoz

    With respect to mid-air collisions, how is a near miss calculated, detected, and reported? Does ATC have radar detection, or is it strictly up to pilots to report a close encounter with another aircraft?

  • First I'd just like to comment that "near miss" is a bad term (as falstro also noticed). It seems to say that the planes "nearly missed", implying they didn't miss. The FAA uses the terms "Near Midair Collision" (NMAC) for serious incidences, and "loss of separation" for less serious ones. As such, terms like "near miss", "close call", and "narrowly escaped disaster" are not well defined.

    ATC does usually have radar. The data is recorded and can be analyzed later. Of course, not all areas have radar coverage. In these cases it is up to pilots to report if they feel safety was compromised. They can use the Aviation Safety Reporting System, which is part of the Aviation Safety Information Analysis and Sharing system.

    Especially with commercial flights, Traffic Collision Avoidance System (TCAS) is also used. If TCAS issues a Resolution Advisory (RA), which commands pilots to take action to avoid a collision, the pilots are usually required to report the incident.

    A "loss of separation" would be anything less than the required separation.

    According the the FAA:

    A near midair collision is defined as an incident associated with the operation of an aircraft in which a possibility of collision occurs as a result of proximity of less than 500 feet to another aircraft, or a report is received from a pilot or a flight crew member stating that a collision hazard existed between two or more aircraft.

    That and more information about reporting incidents can be found in Section 6 of the AIM.

Related questions and answers
  • With respect to mid-air collisions, how is a near miss calculated, detected, and reported? Does ATC have radar detection, or is it strictly up to pilots to report a close encounter with another aircraft?

  • I live near a fairly dangerous road, and I've called 911 a few times to report car accidents outside my home. It's a lot like giving a PIREP - you give the necessary information and the appropriate help is dispatched. All very simple and clean. I've never heard of anyone calling 866-GA-SECURE. What happens when you do? Who do you talk to? Who responds? How fast is the response? What can you expect?

  • I noticed on SkyVector that, for example, the Resolute Bay VOR (YRB) and Baker Lake VOR (YBK) seem to be oriented in such a way that the 360 radial is pointing in the direction of true north (and I don't think the variation is anywhere near zero there). I know VORs are supposed to be oriented according to magnetic north, but is it common practice close to the magnetic poles to have them point true instead? If so, is there any way to tell if a particular VOR is doing just that, except looking at the chart and noticing that the small arrow is pointing north rather than off to one side?

  • I have been using an Android app to track flights. Their information is pulled from their own proprietary database, and some (with 5 minute delay) from the FAA. I was thinking about making an app that would do this as well by pulling from multiple data sources. What are some good APIs, either paid or free, that gives you near realtime data of flying aircraft?

  • I was watching Flight Radar 24, positioned near my house, to see what planes I could spot, and noticed a Cessna 550's transponder just dropped off @ 5,325 ft in a high-speed descent! Is there something I should do about it? Or do I assume somebody in ATC has seen it? Is there anything anyone should do in similar circumstances?

  • Somtimes planes can either come up short or overrun a runway, ending up in the water. Is there some limit for how close a runway can be to the water? Does it factor into the runway safety area that is required to be clear of obstacles (i.e., is water an obstacle)? Is there any requirement for displaced thresholds near water? I am asking primarily about the US, but information about any other jurisdictions is welcome.

  • 135.293(a)(7)(iii) requires that pilots be tested on: (iii) Operating in or near thunderstorms (including best penetrating altitudes), turbulent air (including clear air turbulence), icing, hail, and other potentially hazardous meteorological conditions; So what are the best penetrating altitudes when forced to operate in a thunderstorm? The most obvious answer is to stay out of it in the first place, but the reg requires us to come up with an answer....

  • A popular airport near me (KMYF) has two parallel runways, 28/10 R/L and a crosswind runway, 5/23. Almost always, 28R/L is in use. I'm sure they knew that there was generally a sea breeze in the area, and the wind typically will be right down the runway or within 10-20 degrees of centerline. I'm sure they do prevailing wind study for the area, and my questions are about the study: what are there some specifications for the study? Does the study vary in length depending on location? Is there a standard study that they use, and do they test things like average temperature during the study

  • Quadcopters, by virtue of software-piloting rather than human-piloting, are capable of new modes of flight. I've seen one in which the machine maintains altitude despite the loss of two rotors by spinning (yaw). I wonder about a different mode, though; if a quadcopter could maintain a very high degree of pitch, then the flight is closer to a very short 4-engine X-wing aeroplane. This would be the advantage of a tiltrotor; after takeoff, rotate into the near-vertical position and permit much higher rates as we are no longer limited by usual helicopter dissymetry of lift arguments

  • At first I wasn't even sure if any airlines flew southern Pacific great circle route flights, but it looks like Qantas (QFA27) operates a flight between Sydney and Santiago, Chile. For northern Pacific greate circle routes, you are flying near Canada/Alaska and then Russia for most of the flight, so you have some airports you could potentially divert to if an emergency arose. I've search online for more details about how this works for these flight, but haven't had much luck finding information. Are there any point on the southern Pacific great circle route for flights to divert

Data information