GPWS vs EGPWS
Aircrafts have come a long way from their roots, and more technologies have been introduced to extend the senses of the pilot and increase the safety of the aircraft even in adverse conditions. Two of these technologies are GPWS (Ground Proximity Warning System) and EGPWS (Enhanced GPWS). As you may have already deduced from the names of these two systems, EGPWS is the more advanced system of the two. Thus, GPWS also provides a greater level of security.
GPWS uses an array of sensors to determine whether safety limits are being breached and alerts the pilot. These conditions include: being too close to the ground, diving too fast, banking too steeply, and the like. EGPWS has all the capabilities of GPWS and augments it by using a Global Positioning System, or GPS, to provide very accurate information on the exact location of the aircraft. This is then coupled with an extensive terrain database; basically, a map that details how the ground changes in the area.
GPWS had one very serious flaw; it can only monitor the ground directly beneath it. This can be a problem if there is a very sudden change in the terrain and the GPWS cannot provide a prompt enough warning for the pilot to react to. With EGPWS, the system can track the course of the aircraft and see if it is heading towards a mountain or other similar threat. But it is worth noting that EGPWS is only as good as the terrain database that it has. It needs to be up-to-date and contain accurate information. For example: If a very tall building or tower has been recently built or is under construction and the terrain database does not have that information input, the EGPWS may not be able to detect that it is in a collision course with the structure.
No system is perfect, and both GPWS and EGPWS have their own weaknesses. It’s just a matter of finding these weaknesses and addressing them one by one. This is clear with the evolution from GPWS and EGPWS. The latter may not be perfect, but it is significantly better than the former.
Summary:
1.EGPWS is safer and more advanced than GPWS.
2.EGPWS uses GPS while GPWS doesn’t.
3.EGPWS uses a terrain database that is not available in GPWS.
4.GPWS is only aware of the ground below it while EGPWS is aware of a larger area.