GRAHAM WARWICK / WICHITA
Aims to complete certification 45 months after project go-ahead
Cessna's Citation Sovereign test programme has passed the 15-flight mark within five weeks of the mid-size business jet's maiden flight. Tests so far have included airspeed calibration, stalls, autopilot engagement and thrust-reverser deployment.
Cessna is aiming for certification of the Sovereign in the third quarter of next year, 45 months after project go-ahead. This compares with 60 months for the Citation X high-speed business jet. "The Sovereign is our biggest all-new design since the X," says programme manager Brad Thress.
Thress says that as well as more early testing, there are now 14 system test and 12 structural test articles, which is "many more" than previous programmes.
The first completed airframe is being used for early fatigue testing and has already passed the 3,000-cycle mark.
Cessna's goal was to start flight tests with as mature an aircraft as possible. "There is a correlation between the immaturity of the aircraft and the length of the programme," Thress says. Consequently, there is a lot of emphasis on offline test articles and on parallel tests in the Sovereign programme, he says.
The prototype was complete when it first flew on 27 February, with a handful of unconformed parts that were due to be replaced before the end of the month, Thress says. The aircraft is powered by certificated Pratt & Whitney Canada PW306C turbofans and equipped with the Honeywell Primus Epic integrated avionics planned for production Sovereigns.
The second aircraft is scheduled to fly in the third quarter and will be fitted with an interior for the Sovereign's public debut at the National Business Aviation Association convention in September. The third and final test aircraft is scheduled to fly in the fourth quarter.
While the Sovereign's fuselage is based on that of the Citation X, the moderately swept supercritical-section wing is all-new, as is the cruciform tail, which is supplied by risk-sharing partner Fokker Aero-structures.
The original tail design was based on that of the straight-wing Citations, but elimination of the tailplane dihedral and removal of the dorsal fairing have given the Sovereign a new look as well as improving stability and rudder effectiveness.
Source: Flight International
