Emergency safety alert: FEJ big F-18F Superhornet
Today I was making the fifth flight since new of the big F-18F twin from Fly Eagle Jets (Honeycomb fuselage) that I am flying for a friend.
This jet had already experienced flutter on it's maiden (see Dantley's F-14 crash thread for details) so the rudder system was scrapped and 8711s mounted directly into each rudder with an external linkage and the "Direct Drive" Stabilator/elevon actuation system was also binned because it was grossly insufficient for the task at hand. FEJ supplied the owner/builder with two aluminum trays to install into the aft fuselage with two 8711 servos driving each stabilator half. The trays were reinforced with hardwood maple to insure it was as sturdy as it could possibly be and then installed. We were told by FEJ that this system was the way to go.
On the 2nd flight of the day today, about two minutes into the flight during a very tame right to left pass at about 1/2 throttle the jet experienced massive stabilator flutter of both the left and right flight controls. The right stab ended up almost completely tearing out of the fuselage, servo tray and all and jammed in a position of about 20 degrees nose down (leading edge up). The left stab also broke loose with large flapping movements tip up and down as well as fore and aft.
The aft empennage suffered catastrophic structural failure as well.
For all of you out there who own the big F-18...I strongly advise you not to fly it until this issue is resolved. It is all about safety and in it's current form this jet and the stabilator/elevon/elevator (call it what you wish) is nowhere near sufficient for flight. Massive redesigning and strengthening of the entire back half of the jet is needed in my and others opinion.
Never was the jet exposed to any high speed or high G maneuvers...just simple soft, mild racetrack patterns, a few gentle 1/2 Cuban 8 turn arounds and very very conservative throttle management. Basically, if you watch the flutter sequence in Dantley's F-14 thread...that is exactly what happened with the F-18.
Beave