Editing Ground proximity warning system (section)

== Effects and statistics ==
Prior to the development of GPWS, large passenger aircraft were involved in 3.5 fatal CFIT accidents per year, falling to 2 per year in the mid-1970s. A 2006 report stated that from 1974, when the U.S. FAA made it a requirement for large aircraft to carry such equipment, until the time of the report, there had not been a single passenger fatality in a CFIT crash by a large jet in U.S. airspace.<ref>{{Cite web | last = Sabatini | first = Nicholas | title = Downward Pressure on the Accident Rate | publisher=[[Federal Aviation Administration]] | url = http://www.faa.gov/news/speeches/news_story.cfm?newsId=7170 | access-date =March 19, 2009}}</ref>

After 1974, there were still some CFIT accidents that GPWS was unable to help prevent, due to the "blind spot" of those early GPWS systems.  More advanced systems were developed.

Older TAWS, or deactivation of the EGPWS, or ignoring its warnings when an airport is not in its database,<ref>{{cite web|url=http://www.tvn24.pl/12690,1653907,0,1,lotniska-w-smolensku-moglo-nie-byc-w-bazie-gpws,wiadomosc.html |title="Lotniska w Smoleńsku mogło nie być w bazie GPWS" – Polska – Informacje – portal TVN24.pl – 27.04.2010 |publisher=Tvn24.pl |date=April 27, 2010 |access-date=October 17, 2011}}</ref> still leave aircraft vulnerable to possible CFIT incidents. In April 2010, a [[Smolensk air disaster|Polish Air Force Tupolev Tu-154M aircraft crashed near]] Smolensk, Russia, in a possible CFIT accident<ref>{{cite web|author=Wacław Radziwinowicz, Moskwa, mich |url=http://wyborcza.pl/1,76842,7786163,Sledztwo__Jak_doszlo_do_katastrofy.html |title=Śledztwo. Jak doszło do katastrofy |publisher=Wyborcza.pl |date=April 19, 2010 |access-date=October 17, 2011}}</ref> killing all passengers and crew, including the President of Poland [[Lech Kaczyński]].<ref name="Levin">{{cite news| url=https://www.usatoday.com/travel/flights/2010-04-13-fog-plane-crash-poland_N.htm | work=USA Today | title=Device spurs questions in Polish crash | first=Alan | last=Levin | date=April 13, 2010}}</ref><ref>{{cite web|url=http://www.tvp.info/informacje/swiat/tu154-mial-system-ostrzegania-nie-zadzialal/1663905 |title=Tu-154 miał system ostrzegania. Nie zadziałał? |publisher=Tvp.Info |date=April 15, 2010 |access-date=October 17, 2011}}</ref><ref>{{cite web|url=http://www.fakt.pl/Tu-154-prezydenta-nie-mial-prawa-sie-rozbic-,artykuly,69621,1.html |title=Smolot prezydenta nie miał prawa się rozbić! |date=April 19, 2010 |publisher=Fakt.pl |access-date=October 17, 2011}}</ref><ref>{{cite web|url=http://www.wprost.pl/ar/192532/Nie-bylo-naciskow-na-zaloge-Tu-154-zapis-czarnych-skrzynek-bedzie-upubliczniony/ |title=Wprost 24 – Nie było nacisków na załogę Tu-154, zapis czarnych skrzynek będzie upubliczniony |publisher=Wprost.pl |date=April 16, 2010 |access-date=October 17, 2011}}</ref> The aircraft was equipped with TAWS made by Universal Avionics Systems of Tucson.<ref name="Levin"/> According to the Russian Interstate Aviation Committee, the TAWS was turned on.<ref>{{Cite web |url=http://www.mak.ru/russian/info/news/main_frame.html |title=Untitled Page |access-date=April 24, 2010 |archive-url=https://web.archive.org/web/20100325181802/http://www.mak.ru/russian/info/news/main_frame.html |archive-date=March 25, 2010 |url-status=dead }}</ref> However, the airport where the aircraft was going to land (Smolensk (XUBS)) is not in the TAWS database.<ref>{{cite web |last= |first= |title=Universal Avionics - Error Page |url=http://www.uasc.com/documents/support/usable_datums.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110717130644/http://www.uasc.com/documents/support/usable_datums.pdf |archive-date=July 17, 2011 |access-date=April 24, 2010 |website=www.uasc.com |publisher=Universal Avionics Systems Corporations}}</ref><ref>{{cite web |last= |first= |title=Universal Avionics - Error Page |url=http://www.uasc.com/documents/support/Unknown_Datum_Codes.pdf |url-status=dead |archive-url=https://web.archive.org/web/20170918021247/http://www.uasc.com/documents/support/Unknown_Datum_Codes.pdf |archive-date=September 18, 2017 |access-date=April 24, 2010 |website=www.uasc.com |publisher=Universal Avionics Systems Corporations}}</ref> In January 2008 a [[2008 Polish Air Force C-295 Mirosławiec crash|Polish Air Force Casa C-295M]] crashed in a CFIT accident near Mirosławiec, Poland, despite being equipped with EGPWS; the EGPWS warning sounds had been disabled, and the [[Pilot in command|pilot-in-command]] was not properly trained with EGPWS.<ref>{{cite web|url=http://aviation-safety.net/database/record.php?id=20080123-0 |title=ASN Aircraft accident CASA C-295M 019 Miroslawiec AB |publisher=Aviation-safety.net |access-date=October 17, 2011}}</ref>