System clock updating
The implementation of TCAS added a safety barrier to help prevent mid-air collisions.
However, further study, refinements, training and regulatory measures were still required, because the limitations and misuse of the system still resulted in other incidents and fatal accidents, which include: The airline industry has been working with the Air Transport Association of America (ATA) since 1955 toward a collision avoidance system.
Research into collision avoidance systems has been ongoing since at least the 1950s.
ICAO and aviation authorities such as the Federal Aviation Administration were spurred into action by the Grand Canyon mid-air collision in 1956.
Since the equipment was not developed to full standards, the system was only operated in visual meteorological conditions (VMC).Then, by extrapolating current range and altitude difference to anticipated future values, it determines if a potential collision threat exists.TCAS and its variants are only able to interact with aircraft that have a correctly operating mode C or mode S transponder.In 1981, the FAA announced our decision to implement an aircraft collision avoidance concept called the Traffic Alert and Collision Avoidance System (TCAS).The concept is based upon agency and industry development efforts in the areas of beacon based collision avoidance systems and air-to-air discrete address communications techniques utilizing Mode S airborne transponder message formats.