Advisory for Pilots, Aircrews, Air Controllers, and Aviation Professionals: Unidentified Aerial Phenomena, UAP, UFOs, and Aviation Safety


June 2019


All Rights Reserved


This document is intended to inform pilots, aircrews, air controllers, managers, and the flying public, about; the definition of the term “Unidentified Aerial Phenomena” or “UAP”, the general history of Unidentified Aerial Phenomena, UAP, and aviation, some UAP characteristics, some common profiles of a UAP incident; safety factors that can arise during a UAP incident, cautions and recommendations for aircrews and air traffic controllers, bias and reporting UAP incidents, and what is doing to mitigate this unfortunate situation.

The Definition of Unidentified Aerial Phenomena or UAP

“An Unidentified Aerial Phenomena, UAP, is the visual stimulus that provokes a sighting report of an object or light seen in the sky, the appearance and/or flight dynamics of which do not suggest a logical, conventional flying object and which remains unidentified after close scrutiny of all available evidence by persons who are technically capable of making both a technical identification as well as a common
sense identification, if one is possible.” (Haines, PP 13-22, 1980)

A Very General Overview of the History of UAP and Aviation

Aircrews and Air Traffic Controllers (ATC) have been reporting UAP and UFOs throughout the history of powered flight. Many of these observations and incidents involve safety factors. While the government, usually the military, has had a passing interest in UAP the data has moved away from the aviation community and safety planners, leaving no support for aircrews and ATC. Although the USNAVY has recently implemented a reporting plan to address pilot complaints of safety factors involving UAP, that information is not available to safety planners. The Federal Aviation Administration, FAA, offers no leadership or guidance to civil or commercial aviation and suggests that aircrews and ATC that want to report UAP observations and incidents can do it to somewhere other than the FAA or the US government.

Some UAP Characteristics:

1.   UAP appear as either an unexpected and unusual light (UAP/Light), or object (UAP/Object), or an object with lights attached or nearby.

2.   UAP can appear individually and they can appear in groups.

3.   UAP can vary in size from a foot across to a mile or more.

4.   UAP can appear at any altitude, during any phase of flight, and in controlled/ restricted airspace like airports. UAP can appear during any weather and at any hour.

5.   UAP can be exceptionally mobile and can perform seemingly instantaneous transits, extreme accelerations, acute angle turns, sudden stops, and they can hover in place for long durations. UAP appear to "fly" in a manner that is inconsistent with fluid dynamics. Their movements can appear "odd" and can be entirely unexpected and startling for witnesses.

6.   UAP have been detected intermittently on ground radar. Often pilots contact ATC for radar confirmation and, often, there is no detection by ground radar. This may be a characteristic of aviation-related UAP encounters.

Some Profiles of Aviation-related UAP Incidents:

1.   UAP incidents nearly always begin with aircrews in flight observing something unusual and unexpected.

2.   UAP incidents can be a distracting observation of something at a distance. A crew may or may not report it real time to air controllers or after the fact.

3.   UAP incidents can escalate very quickly from a simple observation of a stationary or pacing object or light to a loss of separation or a collision heading.

4.   UAP can appear suddenly and cause or require immediate control inputs.

5.   UAP incidents can include temporary or permanent failures of electronic, communications, and navigation systems.

6.   UAP incidents can have durations of a few seconds to several hours.

7.   UAP incidents can repeat in the same general area over time. Locations can be known for UAP activity.

8.   UAP incident profiles are consistent in that they are UNEXPECTED and UNPREDICTABLE. There can be no confidence in the headings and behaviors of UAP during an incident.


Aviation Safety Factors During UAP Incidents:

  • Loss of Separation:

    UAP can close to much less than 1000ft required for conflict avoidance.

  •   Collision Headings and Near Midair Collisions:

    UAP reports include descriptions of close passes and near-collision headings including Head-on passes.

  • Crew Distraction:

    UAP can appear during any phase of flight and inside controlled airspace. Aircrews are distracted and watching UAP when they are present, and this can adversely affect flight safety.

  • Electrical Systems Failures

    Failures of communications, navigation, and autopilot, and other electrical systems have occurred during UAP encounters. Depending on the nature of the encounter, this could compound safety issues.

  •   Obstacles in Controlled/ Restricted Airspace

    UAP incidents inside of restricted or controlled airspace are a hazard to aircraft. 

  •   Intermittent Radar Detection as a Safety Factor

    UAP are not always visible to ground radar.

    Air controllers are not able to identify an obstacle or hazard.

    UAP transparency to radar can defeat radar dependent anti-collision systems. Transponder-dependent Anti-Collision Systems, TCAS, will not detect UAP.

  • Unpredictability as a Safety Factor

    UAP can move with extreme speeds on unpredictable trajectories. They can appear suddenly in the path of an aircraft. ACS, if present, may not activate, TCAS will not activate. Control inputs to avoid a collision may occur or be necessary.

  •   Lack of Guidance and Training as a Safety Factor

    UAP cases primarily involve the aircrew making judgment calls based on real-time developments. The failure to prepare them in advance for these incidents directly effects their ability to mitigate risk, inhibits discussion of UAP incidents amongst themselves, with ATC, and with managers during an incident and after, and adversely affects reporting and data collection.

Cautions and Recommendations:

The majority of UAP reports involve an initial visual detection by an aircrew. It is uncommon for ATC to detect a UAP and vector aircraft around them though, in some cases, aircraft have been able to gain ground radar confirmation of the presence of a UAP.

Pilots and ATC that are confronted by UAP observations and incidents are in an unusual and challenging situation. They are generally unaware of the existence of UAP, slow to realize what they are dealing with, and understandably incredulous when confronted by them. In some situations, the seriousness of the matter is not immediately apparent to pilots and air controllers and communication is inhibited by professional and personal biases. There is no professional guidance or information to inform and help mitigate aviation encounters with UAP.

The unpredictable behavior of UAP is hazardous. Aircrews and ATC involved in a UAP incident or observation can not have any confidence in the headings and behaviors of UAP and should be defensive and conservative in response to any observation or incident.

There is no reliable way to determine if UAP avoid collisions. The range of separation and rate of closure in some cases demonstrated a clear need for control inputs to avoid a perceived collision with many more cases reporting near mid-air collisions, loss of separation and very close pacing. There is an opinion that some UAP are piloted and want to avoid a collision. Given that some UAP may be natural, and very potent, electrical phenomena that are unlikely to “want” to avoid a collision, aircrews cannot safely assume that UAP will “just get out of the way” on their own.

Ultimately it is the aircrew's good judgment and ability to assess the risk that defines an appropriate response to danger. It is the responsibility of the aviation system to inform aviation professionals and mitigate UAP incidents through education and training that prepares them.

Bias and Reporting

There is a bias against reporting UAP observations inside the aviation community that contributes to the overall failure to acknowledge and to mitigate UAP and aviation-safety factors. Many pilots and air controllers consider the subject to be hazardous to their image and careers and often do not report their experiences until after they have retired.

The FAA has no interest in accepting pilot and aircrew reports involving UAP or UFO. The FAA AIM manual instructs pilots and aircrews to contact a civilian ufo reporting service. This contributes to a bias against reporting and a failure to collect data and mitigate risk.

NARCAP has conducted an aircrew survey of a regional US carrier regarding UAP observations and incidents. There was a very high response rate, 28%, and aircrews indicated a high interest in the issue of UAP and aviation safety.

Aircrews, air controllers, and aviation professionals are encouraged to contact online, via email, or phone to report UAP/ UFO observations and incidents. NARCAP strongly suggests that pilots, air controllers, and aviation professionals also make a report to the confidential FAA Aviation Safety Reporting System (FAA ASRS).



NARCAP has been documenting and researching aviation-safety related incidents involving UAP since 1999. NARCAP defined and established the term UAP. NARCAP has been advocating for further research and education inside the aviation community to acknowledge and mitigate risks arising from UAP for over twenty years.




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Federal Aviation Administration Airman Instruction Manual (AIM) – Reporting UFOs

Roe/ NARCAP 2004, Aviation Safety in America - Under-Reporting Bias of Unidentified Aerial Phenomena and Recommended Solutions

Haines/ NARCAP 2007, Report of an Unidentified Aerial Phenomenon and its Safety Implications at O'Hare International Airport on November 7, 2006

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