Humes McCoy Aviation Sheds Light on the EGPWS Basics

Current enhanced ground proximity warning computers are a natural outgrowth of the original system developed in the 1970s. One of the earliest GPWS computers was based on the Intel 8080 microprocessor, the first use of a microprocessor in a commercial avionics unit. It relied on the radio altimeter for its primary input and had distinct limitations as a result.

“Modern EGPWS units are attached to the aircraft GPS for position, altitude, course and speed,” stated Thay Humes, Co-founder of Humes McCoy Aviation. These units also receive a variety of discrete signals. They monitor flight modes during approach and departure and provide warnings if the aircraft is misconfigured, improperly lined up during an approach, or on a runway that is too short.

The main task for EGPWS is to provide pilot awareness and prevent controlled flight into terrain. The computer takes GPS information and compares it to a simplified terrain map. It displays the results with color-coded altitudes. The terrain below the aircraft altitude is green. Any terrain near the same altitude is yellow, and terrain that is higher than the aircraft is red. When a collision is possible, the EGPWS computer will override the weather radar display and provide an audible warning.

EGPWS also contains a database of antenna towers, high-tension lines, and other man-made obstacles. As new structures are built, the database must be updated regularly.

Terrain awareness systems save lives. Since 1992, the FAA has required EGPWS on all turbine-powered aircrafts capable of carrying 10 or more passengers. They continue to evolve, leading to greater precision and effectiveness.

About Humes McCoy Aviation:

Humes McCoy Aviation is an innovative aircraft management company and operator that believes in providing safe and reliable aviation services. They are a private aircraft leasing company that helps curtail the hassles associated with commercial air travel. Humes McCoy Aviation provides simple and personalized air transportation to clients, giving them peace of mind as well as the power to fly to countless destinations.