ergo a écrit :Dès le matin !
Ça a mis du piment dans mes CornFlak's !
Meanwhile, Lockheed Martin is working through the implications of design changes already made to combat weight. One of the most significant was abandonment of the rapid-mate production joints in the wing carry-though structure, originally designed to reduce production time. "It led to some inherent inefficiency in structural weight, and by cutting that we saved around 1,000lb [450kg]," says Burbage.
The bad news, however, is the alternative design adds 26 days to the overall assembly time, which adds extra cost. "To offset the increase in assembly time, we are going to a moving assembly line, which has brought back about half the span time," says Burbage, adding that further improvements are being sought.
From a general standpoint, the JSF team is also ensuring the F-35 avoids the pitfalls of earlier designs such as the F/A-18E/F and F/A-22. To avoid the lateral directional instability problems experienced by the F/A-18, with its wing drop phenomenon, all variants of the F-35 design will feature a simple, single leading-edge flap.
Similarly, the design team has spent a long time looking at high angle-of-attack (alpha) flow characteristics to see if the F-35 might be susceptible to the vertical tail buffet issues encountered by the F/A-18 and F/A-22. "It's a good thing we did that," says Burbage, adding that the windtunnel tests show the F-35 chine does indeed generate a strong vortex at high alpha, and that flight tests would have revealed a distinct tail buffet. Structural reinforcement is being designed into the aircraft's F-35 vertical fins as a result of the tests says Burbage. He adds: "We are bound to have enough of our own problems without repeating those of others."
Flying testbed
On note: To avoid the lateral directional instability problems experienced by the F/A-18, with its wing drop phenomenon, all variants of the F-35 design will feature a simple, single leading-edge flap.
Tout le monde sait que la version navale experience ces problemes.
F-35C Spoiler Tackles Wing Drop Posted by Graham Warwick at 8/5/2009
After the F/A-18E/F experience, Lockheed Martin conducted windtunnel tests specifically to look for wing drop. On the CTOL F-35A and STOVL F-35B, J.D. says, careful scheduling of the leading- and trailing-edge flaps looked to control the phenomenon, but on the CV F-35C the combination did not seem enough. So the decision was taken to add the spoilers, which pop up to disturb the flow over both wings and keep the aerodynamics consistent on left and right.
http://www.aviationweek.com/aw/blogs/de ... d=blogDest
A part ca ils ne se sont pas plantes...
On note: The windtunnel tests show the F-35 chine does indeed generate a strong vortex at high alpha, and that flight tests would have revealed a distinct tail buffet.
Resultat: Structural reinforcement is being designed into the aircraft's F-35 vertical fins as a result of the tests says Burbage.
Qu'on m'explique, plus de poid, moins de stealth (titanium au lieu de composite) c'est pas du plantage?
http://www.flightglobal.com/articles/20 ... tters.html
Bon, maintenat qu'on a etabli la nature du probleme ET de quelle version il s'agit, on peut porter le debat a un niveau plus eleve... Peut etre...
Y'a des gens ici qui prennent un malin plaisir a se faire remarquer en s'en prenant au posteur et evitant soigneusement d'argumenter et de se renseigner, ca pourri le debat tres vite et malgres les efforts que je peut faire pour informer les gens, on se dirige encore une fois vers un autre topic ferme ou le desormais classique "Dare2 est un troll Modos SVP faut la bannir"...
:busted_bl
Defense Secretary Robert Gates has put the U.S. Marine Corps’ troubled F-35B short-takeoff-and-vertical landing (Stovl) Joint Strike Fighter on “probation,” while endorsing the U.S. Air Force’s long-coveted new bomber program.
