Editing Aegis Combat System (section)

===Iran Air Flight 655===
{{Main|Iran Air Flight 655}}

[[File:CG-47 CIC.png|thumb|upright|Layout of the [[Combat Information Center]] of early Aegis cruisers]]

The Aegis system was involved in a disaster in which {{USS|Vincennes|CG-49|6}} mistakenly shot down [[Iran Air Flight 655]] in 1988 resulting in 290 civilian deaths.

A formal military investigation by the United States Navy concluded that the Aegis system was completely operational and well maintained. The investigation found that if the [[commanding officer]] had relied on the complete tactical data displayed by the Aegis system, the engagement might never have occurred. Additionally, psychological effects of the crew subconsciously manipulating the data to accord with a predefined scenario greatly contributed to the false identification. The investigation found that the Aegis Combat System did not contribute to the incident and that the system's recorded target data contributed to the investigation of the incident. The discrepancies between the Aegis data report and what the ship's personnel reported to the commanding officer are as follows:<ref>{{Cite web |last=Fogarty |first=William M. |date=July 28, 1988 |title=Formal Investigation into the Circumstances Surrounding the Downing of Iran Air Flight 655 on 3 July 1988 |url=http://www.dod.mil/pubs/foi/International_security_affairs/other/172.pdf |archive-url=https://web.archive.org/web/20060506205901/http://homepage.ntlworld.com/jksonc/docs/ir655-dod-report.html |archive-date=6 May 2006 |access-date=March 31, 2006 |id=93-FOI-0184}}</ref>

{| class="wikitable"
|-
! Aegis Data Report
! Personnel Report to CO
|-
| Iran Air Flight 655 continuously ascended in duration of flight
| Iran Air Flight 655, after attaining {{convert|9000|to|12000|ft|m|abbr=on}}, reportedly descended on an attack vector on USS ''Vincennes''
|-
| Iran Air Flight 655 continuously squawked [[Transponder (aviation)#Transponder modes|Mode III]] [[identification, friend or foe]] (IFF) in duration of flight
| Iran Air Flight 655 reportedly squawked Iranian [[F-14 Tomcat]] on Mode II IFF for a moment; personnel proceeded to re-label the target from "Unknown Assumed Enemy" to "F-14"
|-
| Iran Air Flight 655 held consistent climb speed in duration of flight
| Iran Air Flight 655 was reported to increase in speed to an attack vector similar to an F-14 Tomcat
|-
|}

Other analyses found that ineffective user interface design caused poor integration with the crisis management human processes it was intended to facilitate. The Aegis System software shuffles target tracking numbers as it gathers additional data. When the captain asked for a status of the original target identifier TN4474, the Aegis system had recycled that identifier to a different target which was descending, indicating possible attack posture.<ref>{{cite journal |last1=Fisher |first1=Craig |last2=Kingma |first2=Bruce |date=2001 |title=Criticality of data quality as exemplified in two disasters |journal=Information and Management |volume=39 |issue=2 |pages=109–116 |doi=10.1016/S0378-7206(01)00083-0 |citeseerx=10.1.1.15.1047 |s2cid=13015473 }}</ref> An article by [[David Pogue]] in ''[[Scientific American]]'' rated it as one of the five "worst digital user-interface debacles of all time."<ref>{{cite magazine |last=Pogue |first=David |date=1 April 2016 |title=5 of the Worst User-Interface Disasters |url=https://www.scientificamerican.com/article/pogue-5-of-the-worst-user-interface-disasters/ |magazine=Scientific American |access-date=3 July 2019 |archive-url=https://web.archive.org/web/20160922042401/http://www.scientificamerican.com/article/pogue-5-of-the-worst-user-interface-disasters/ |archive-date=22 September 2016 |url-status=live }}</ref>