Ground proximity warning system
A ground proximity warning system (GPWS) is a system designed to alert pilots if their aircraft is in immediate danger of flying into the ground or an obstacle. The United States Federal Aviation Administration (FAA) defines GPWS as a type of terrain awareness warning system (TAWS).[1] More advanced systems, introduced in 1996,[2] are known as enhanced ground proximity warning systems (EGPWS), a modern type of TAWS.
In the late 1960s, a series of controlled flight into terrain (CFIT) accidents took the lives of hundreds of people. A CFIT accident is one where a properly functioning airplane under the control of a fully qualified and certified crew is flown into terrain, water or obstacles with no apparent awareness on the part of the crew.[3]
Beginning in the early 1970s, a number of studies examined the occurrence of CFIT accidents.[3] Findings from these studies indicated that many such accidents could have been avoided if a warning device called a ground proximity warning system (GPWS) had been used. As a result of these studies and recommendations from the U.S. National Transportation Safety Board (NTSB), in 1974, the FAA required all large turbine and turbojet airplanes to install TSO-approved GPWS equipment.[3][4]
The UN International Civil Aviation Organization (ICAO), recommended the installation of GPWS in 1979.[5]
C. Donald Bateman, a Canadian-born engineer, developed and is credited with the invention of GPWS.[6]
In March 2000, the U.S. FAA amended operating rules to require that all U.S. registered turbine-powered airplanes with six or more passenger seats (exclusive of pilot and copilot seating) be equipped with an FAA-approved TAWS.[3] The mandate affects aircraft manufactured after March 29, 2002.[7]
