Cessna Sovereign Program on Track

Cessna flight test engineers were closing in on 40 missions and 75 hours of flight test in the prototype Sovereign as of May 28. First flight was on February 27.

Designed to fill the niche between traditional mid-size and the new super mid-size jets, Sovereign's strong suit is superior short field performance and a Citation X-size double-club cabin.

Each test flight now has been stretched to 2.6 to 2.7 hours, thereby increasing the number of development test objectives per flight, according to Brad Thress, Sovereign program manager. The prototype aircraft will be used for aerodynamic development tasks, such as envelope expansion, stability and control, flutter and handling characteristics. Initial stall tests have been completed in all configurations, throughout the CG envelope, and runway performance has been validated. The correlation between performance estimates and flight test data "looks good," Thress asserted.

Windmilling and starter-assisted engine starts in flight also have been accomplished, along with Honeywell Primus Epic digital flight guidance system tests.

Sovereign serial number 680-P1, the second flight test and first production aircraft, completed ground engine runs and taxi tests last week in preparation for its first flight in mid summer. It will be used for systems development, hot and cold weather environmental tests, and it will be the certification aircraft.

A third flight test aircraft, 680-P2, will join the program near the end of the year. It will be used for avionics work, function and reliability tests, and to gather control law data for simulator certification. This will mark the first time Cessna has done its own simulator data collection flights and it's intended to accelerate simulator development so that it will be FAA approved when initial customer deliveries begin early in 2004.

Sovereign, while appearing to be yet another Citation Model 500 variant, actually will have new type certificates. "We're enveloping the test requirements for both FAR and JAR Part 25 certification," Thress commented. FAR 25 certification is slated for late 2003 and JAR 25 approval is scheduled for early 2004.

By Fred George