The Citation V, Citation Ultra and Ultra Encore are the largest straight wing members of Cessna's highly successful Citation family.Cessna publicly announced it was developing a stretched development of the Citation II at the annual NBAA convention in New Orleans in 1987. Earlier in August that year the first engineering prototype Model 560 Citation V had successfully completed the type's maiden flight. A preproduction prototype flew in early 1986, while US certification was granted on December 9, 1988. Deliveries began the following April.
The Citation V was based on the Citation II/SP, but differences over the smaller jet include more powerful Pratt & Whitney Canada JT15D5A turbofans and a slight fuselage stretch, allowing seating in a standard configuration for eight passengers. The Citation V proved quite popular, with 262 built through to mid 1994 before production switched to the modernised Ultra.
Cessna announced development of the upgraded Citation V Ultra in September 1993. FAA certification was granted in June 1994, allowing for deliveries of production aircraft to commence soon after. Compared with the Citation V, the Ultra features more powerful 13.6 kN (3045 lb) Pratt & Whitney Canada JT15D5D engines and Honeywell Primus 1000 EFIS avionics with three CRT displays (two primary flight displays and one multifunction display).
The Citation Ultra Encore is a new development announced at the 1998 NBAA convention. Compared with the Ultra the Encore introduces new Pratt & Whitney Canada PW535 engines, plus trailing link main undercarriage, more fuel payload, updated interior and improved systems. The Ultra's Honeywell Primus 1000 EFIS avionics suite is retained.
In 1993, Cessna decided to update the Citation V design, and announced the Citation Ultra Powered by Pratt & Whittney JT15D-5D engines with 3045 lbs of thrust and the standard avionics suite, which was updated to the Honeywell Primus 1000 EFIS glass cockpit. The Primus 1000 replaced the standard "round dial" flight instruments with three CRT computer screens, one for each pilot and one center mulifunction display. In 1994, the Ultra was named Flying magazine's "Best Business Jet". The Ultra was produced from 1994–1999. Both the Citation V and Ultra hold 5816 pounds of fuel.
The UC-35A is the United States Army designation and UC-35C is the United States Marine Corps designation for the Citation Ultra, which replaced older versions of the C-12 Huron.
Another version of the Model 560 is the OT-47B "Tracker", five of which were purchased by the Department of Defense for use in drug interdiction reconnaissance operations, based at Maxwell Air Force Base. The OT-47B utilizes the F-16's APG-66(V) fire control radar system and the WF-360TL imaging system. The OT-47Bs have been operated on loan to the Colombian Air Force and Peruvian Navy.
Five years later, in 1998, the Model 560 was upgraded again as the Citation Encore, with Pratt & Whitney Canada PW535A engines and a decrease in fuel capacity to 5,440 pounds, 360 pounds less than the Ultra's, but it has more range than the Ultra-1,700 nmi with NBAA IFR reserves. The reduction in fuel tank size allowed Cessna to fit the Encore with soft-landing, trailing link, main landing gear, a welcome change for pilots who griped about the notorious kerplunk touchdown characteristics of the stiff-legged earlier Citations aircraft. In addition, the wheel track has been narrowed 3.7 feet for better ground tracking and more mannerly crosswind landing behavior. The Encore's standard equipment list have been increased and many systems have been upgraded. Bleed air is used to anti-ice the wing leading edge, and several boundary layer energizers, plus a stall fence, have been added to the wing to improve stall characteristics. A digital pressurization controller reduces pilot workload and an improved wheel brake system offers better modulation. Redesigned interior fittings and passenger seats provide more seated headroom. New passenger service units provide more even airflow and temperature control. The Encore's MTOW is bumped 330 pounds to 16,630 pounds, enabling it to carry five passengers with full fuel. The additional weight increases takeoff field length to 3,561 feet, compared with 3,180 feet for the Ultra. The much improved high altitude thrust output of the PW535 engines, however, allow the Encore to climb faster and cruise higher. Its maximum cruise altitude is FL 450. The Encore was certified in April 2000 with first delivery in late September 2000. The next upgrade was the Citation Encore+, with the addition of FADEC-controlled PW535B engines and Rockwell-Collins Pro Line 21 avionics suite. The Encore+ was certified by the FAA in December 2006, with deliveries of production aircraft expected in the first quarter of 2007.
The UC-35B is the Army designation and UC-35D is the Marine Corps designation for the Citation Encore.
- Citation V : (Model 560), growth variant of the Citation II/SP JT15D-5A
- Citation Ultra : (Model 560) upgraded Citation V with JT15D-5D, EFIS instruments
- Citation Encore : (Model 560) upgraded Citation Ultra with PW535A engines and improved trailing-link landing gear
- Citation Encore+ : (Model 560) upgraded Encore includes FADEC and a redesigned avionics.
- UC-35A : Army and Air Force transport version of the V Ultra.
- UC-35B : Army transport version of the Encore
- UC-35C : Marine Corps version of the V Ultra.
- UC-35D : Marine Corps version of the Encore.
- OT-47B "Tracker" : The DoD purchased five OT-47B models for drug interdiction reconnaissance.