Ratheon aircraft has completed testing of a modified elevator on the Premier I entry-level business jet. The design change, to improve gust response at high altitude, has pushed already-delayed certification back to the fourth quarter.
The elevator was modified after Raytheon discovered the Premier's gust response above 31,000ft (9,450m) did not comply with US Federal Aviation Administration (FAA) certification guidelines. Rules require the aircraft to be able to recover from a gust upset within two pitch cycles; the Premier required two and a half. "It was a matter of 5s instead of 4s to recover," the company says.
The modification, which involves adding a small strip along the trailing edge of the elevator, has been flight tested and the aircraft's gust response now complies with FAA guidelines, Raytheon says, but the redesign added over a month to the certification schedule.
US certification and first deliveries are now planned for the fourth quarter, but Raytheon still has a number of certification flight tests to complete, including flight in natural icing and 150h of function and reliability flying. The company says "over 90%" of flight test conditions had been completed by late September.
Raytheon says the additional delay has not lost it any of the more than 250 orders it holds for the$4.8 million Premier I.
One reason, the company says, is that the aircraft "meets or exceeds" its cruise speed, range and payload guarantees.
Source: Flight International
