Cessna Citation II

===Citation S/II===
The improved '''Citation S/II''' (Model S550) was announced in October 1983 and first flew on February 14, 1984, before certification in July.<!--<ref name="alnet550"/>-->
It gained a [[supercritical airfoil]] with swept wing roots, [[aileron]] and [[flap (aeronautics)|flap]] gap seals, and a [[Ice_protection_system#Fluid_deicing|fluid deicing]] system instead of the [[Ice_protection_system#Pneumatic_deicing_boots|pneumatic deicing boots]] used on earlier Citations.<ref name=aopa2011/><ref name="alnet550"/>{{sfn|Szurovy|1999|p=31}}
To further reduce drag, the fuselage and engine [[nacelle]] pylons were redesigned, and nacelle fairings were added.<ref name=aopa2011/>{{sfn|Szurovy|1999|p=31}} Fuel capacity was increased by {{cvt|120|gal|L}}. The result of the improvements was a cruise speed of {{cvt|403|kn|kph}}—exceeding 400 kn, felt to be an important marketing benchmark by Cessna—and a range of {{cvt|1,378|nmi|km}} with a 45-minute [[fuel reserve]].{{sfn|Szurovy|1999|pp=31–32}}
The improved {{cvt|2500|lbf|kN}} JT15D-4B engines had higher temperature-rated components, allowing more thrust at higher altitudes.<ref name=aopa2011/>

The S/II replaced the II from 1984, but some potential buyers objected to the sharp price increase from {{Currency|2.6 million|US|passthrough=yes}} for the II to $3.3M for the S/II, prompting Cessna to reintroduce the II<ref name=aopa2011/> in late 1985; both were built until the Bravo was introduced.<ref name="alnet550"/> Deliveries of the S/II amounted to 160, including fifteen T-47A aircraft purchased by the [[U.S. Navy]].<ref name=Cessna28apr2015/>{{sfn|Szurovy|1999|p=32}} The S/II's higher performance coupled with its relatively low production total led to substantially higher demand on the used aircraft market compared to the standard II and II/SP.<ref name=aopa2011/>

====Government variants====
The [[US Customs & Border Protection]] purchased ten Citation IIs configured with [[fire control radar]] (initially the [[F-16]]'s [[AN/APG-66]](V), later the [[Selex ES]] Vixen 500E system) and the WF-360TL imaging system.<ref>[http://www.cbp.gov/linkhandler/cgov/border_security/am/operations/oam_vessels/aircraft/fw_aircraft/c550_cessna_factsheet.ctt/c550_cessna_factsheet.pdf Cessna C-550 Fact Sheet]{{dead link|date=August 2017 |bot=InternetArchiveBot |fix-attempted=yes }} Retrieved 21 August 2011.</ref> These aircraft have been used effectively in Panama, Honduras, Colombia, Peru, Venezuela, Mexico and Aruba. The similar OT-47B aircraft are based on the [[Cessna Citation V]] airframe.

[[File:T-47A Citation aircraft are parked on the runway. The Citation is used for training naval flight officers - DPLA - 115f98dfa39a6f8ed00c920f88833139.jpeg|thumb|Several U.S. Navy T-47A radar systems trainers seen in 1989]]
The '''T-47A''' was a modified version of the Citation S/II (Model 552) for the U.S. Navy, featuring a {{cvt|5|ft|m|abbr=on}} wingspan reduction and hydraulically boosted [[aileron]]s for enhanced maneuverability, {{cvt|2900|lbf|kN}} thrust JT15D-5 engines, a cockpit roof window for better pilot visibility during hard maneuvering, strengthened windshields for protection against [[bird strike]]s during high-speed low-altitude sorties, multiple radar consoles, and the [[AN/APQ-159|AN/APQ-167]] radar system.{{sfn|Szurovy|1999|p=21}}<ref>{{cite report|title=Model Designation of Military Aerospace Vehicles|url=https://www.esd.whs.mil/Portals/54/Documents/DD/issuances/dodm/412015l.pdf?ver=2018-12-11-100011-077|publisher=[[United States Department of Defense]]|id=DoD 4120.15-L|date=12 May 2004}}</ref><ref name="global"/> Intended to replace the [[North American Sabreliner|North American T-39D]] as a radar systems [[trainer aircraft]], fifteen aircraft were purchased in 1984 to train naval [[radar intercept officer]]s.{{sfn|Szurovy|1999|p=21}}

All T-47A aircraft were operated with civil [[aircraft registration]] numbers by Training Air Squadron [[VT-86]] based at [[Naval Air Station Pensacola]], Florida. On July 20, 1993, thirteen of the fifteen aircraft were destroyed when a roofing contractor accidentally set fire to a hangar at [[Topeka Regional Airport|Forbes Field]] where the aircraft were being stored by Cessna. The navy replaced the lost trainers with upgraded T-39D aircraft and the two survivors were transferred to civil owners.<ref name="global">{{cite web|url=http://www.globalsecurity.org/military/systems/aircraft/t-47a.htm |title=T-47A Citation II Cessna 552|website=globalsecurity.org|access-date=5 March 2021}}</ref><ref>{{cite web |url=http://www.joebaugher.com/navy_serials/thirdseries21.html |title=US Navy and US Marine Corps BuNos, Third Series (160007 to 163049) |last=Baugher |first=Joe |date=February 27, 2021 |website=joebaugher.com |access-date=March 5, 2021}}</ref>