The Cessna Aircraft Company recently announced that Citation Sovereign Part 135 operators will now be able to conduct certain over-water flights, specifically Los Angeles to Hawaii, without requiring FAA Extended Operations (ETOPS) approval.
According to Cessna, analysis proves the aircraft can fly 1,022 nautical miles -- just over halfway between Hawaii and Los Angeles -- in less than 180 minutes at the engine-out flight profile. To qualify for the ETOPS exemption, a passenger aircraft flying with an engine out must never be more than 180 minutes from a suitable airport.
Technical details, provided by Cessna:
Cessna Engineering conducted an analysis using worst case weight and determined the Model 680 Sovereign is capable of traveling a distance of 1,022 nm in 180 minutes (under standard conditions in still air) after an engine failure. This analysis is based on a sea level takeoff at maximum takeoff weight (30,300 lbs), a direct climb to 43,000 feet using the Operating Manual multi-engine climb profile, followed by cruise at maximum cruise thrust.“This is a response to customer requests for help in meeting this profile as L.A. to Honolulu is sure to be a popular route with Cessna’s charter operators,” said Roger Whyte, senior vice president, Sales & Marketing.
At the engine failure point (1022 nm into the trip and weight of 26,209 pounds) the airplane drifts down using the Operating Manual drift down procedures to the drift down altitude. Upon reaching the drift down altitude, the airplane then descends at a rate of 3,000 fpm at a speed of VMO/MMO – 10 knots to 25,000 feet.
At 25,000 feet, the aircraft levels and cruises using maximum continuous thrust until starting the final descent to the diversion airport. The final descent is flown at a rate of 3,000 fpm and VMO -10 knots from 25,000 feet to 10,000 feet and then at 250 KIAS at idle thrust until reducing speed for landing.
This profile will support several of the over-water missions Sovereign operators desire to fly. The key in planning missions of this type is to maintain a maximum 1,022 nm or smaller radius from a suitable landing airport.
The operational guidance for this procedure will be included in the next revision (Revision 8) of the 680 Airplane Flight Manual (AFM) due out in early 2010.