Soaring flight can present unique challenges related to visual scanning and collision avoidance. By nature of the activity, gliders often have no choice but to congregate in areas of lift, flying with far less separation than most other types of flying activities (except formation flying!). As such, glider pilots employ some unique strategies to address and mitigate this risk. ## Visual Scanning The visual scanning techniques used in a glider are the same used in any other aircraft. Glider pilots have the advantage of flying more slowly, and maneuvering more often than other types of aircraft, but in much closer proximity to one another. A **continuous** visual scan in **all areas** around the aircraft is critical! For more information, reference the following resources: [[Medical Facts for Pilots](https://www.faa.gov/air_traffic/publications/atpubs/aim_html/chap_8.html)]() [[Chapter 17: Aeromedical Factors | Federal Aviation Administration](https://www.faa.gov/regulationspolicies/handbooksmanuals/aviation/phak/chapter-17-aeromedical-factors)]() [[AC 90-48E - Pilots’ Role in Collision Avoidance](https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentID/1041368)]() ### Blind Spots Blind spots vary highly by aircraft design, but gliders generally have excellent visibility. Most gliders have a blind spot approximately 45° behind and 45° below the cockpit. Additionally, high-wing designs (ie SGS 2-33) will have a blind spot above and to the side. If you can't see the other pilot's head, they can't see you! ![[Bill Palmer glider blind spots.jpg]] ![[AFH blind spots.png]] ## Flying in Lift [[Collision Avoidance During Thermal Soaring]] [[Terrain and Collision Avoidance During Ridge Soaring]] ## Anti-Collision Lighting Anti-collision lights are not required for gliders in the US. Installation of anti-collision lights can greatly increase the chances of being seen, and are typically minimally intrusive to the glider. ![[canopy flasher.jpg]] ## Transponder and ADS-B Requirements Aircraft equipped with **TCAS** (typically large and jet-powered aircraft) are able to detect other aircraft equipped with operable altitude-encoding transponders. Aircraft equipped with **ADS-B in** are able to detect other aircraft equipped with operable ADS-B out. Most gliders in the US do not have a transponder or ADS-B out - from the Aeronautical Information Manual: Transponder and [ADS-B](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-a.html#$ADS-B) Out requirements do not apply to any aircraft that was not originally certificated with an electrical system, or that has not subsequently been certified with such a system installed, including balloons and gliders. These aircraft may conduct operations without a transponder or [ADS-B](https://www.faa.gov/air_traffic/publications/atpubs/pcg_html/glossary-a.html#$ADS-B) Out when operating: - Outside any Class B or Class C airspace area; and - Below the altitude of the ceiling of a Class B or Class C airspace area designated for an airport, or 10,000 feet MSL, whichever is lower. For more information, see §91.215, §91.225, AIM 4-1-20 ## FLARM ### What is FLARM? FLARM, derived from "flight alarm", is a collision-warning unit designed to assist the pilot in seeing and avoiding potential conflicts. Development of FLARM began in 2004 in response to numerous mid-air collisions between gliders. ### How does FLARM work? FLARM uses an internal GPS receiver and pressure sensor to accurately determine aircraft position, and broadcasts the predicted flight path of the aircraft at one second intervals. Any FLARM equipped aircraft within range will receive this signal. Each FLARM unit compares its own predicted flight path with the signals it receives (and an obstacle database) and alerts the pilot of a potential collision hazard. ## Parachutes Parachutes are not required by regulation (§91.307) for normal glider flight operations, however, may pilots elect to wear them as an additional risk mitigation measure. They are typically required for contest soaring (ie SSA competitions), as the traffic density and competitive nature of the activity increases the likelihood of a mid-air collision. ## Training Flight instructors should emphasize and mandate good visual scanning habits from the very beginning of flight training. In addition to teaching the required scanning techniques and collision avoidance practices, instructors must also develop a pilot's "division of attention" and "task management" skills for the correct habits to become effective. Loss of traffic separation **and** loss of control accidents are both often the result of a distracted pilot; as such, instructors must implement realistic distractions during flight training to ensure a pilot is ready to safely deal with any unexpected circumstances that arise in flight. ## References - FAA, *Glider Flying Handbook - FAA, *Airplane Flying Handbook* - Aeronautical Information Manual - 14 CFR Part 91 - https://www.flarm.com/en/about-us/ - https://www.flarm.com/wp-content/uploads/2024/04/FLARM_OperatingManual_E.pdf