Apertures are a tough thing to design for stealth aircraft. The aircraft has to be stealthy, yet let antennas and radar detectors peak through the skin without creating adverse radar concerns.
The F-35 has 10 apertures that pertain to radar detection as can be seen from this graphic.
As a comparison, the F-22--sometimes described as an antenna farm--has around 30 apertures on the airframe.
Production quality has nagged the F-35 program even while proponents complain more aircraft need to be built per year. The problem with building a higher quantity of F-35s is that what is currently being built are "mistake-jets" because of production knowledge immaturity.
The electronic warfare concern may have been one of the classified issues mentioned in last years DOD "quick-look" report" pointing to a variety of F-35 troubles.
Electronic warfare is an interesting term with the F-35. It has no wide field of view self-defense jamming equipment. One of the assumptions is that the narrow-band and narrow field of view radar in the nose will perform some jamming functions. Due to the cooling issues and sustained power with AESA radars, this is probably not a very reliable function. The aircraft will have narrow-band, mostly nose-on low-observable capability and some expendable decoys. A towed decoy--combat proven in ALLIED FORCE 1999--is not expected until Block 4. Whenever that happens.
A paper on predicted F-35 survivability can be read here.
15 comments:
I believe its less detectable, but i think even current radar systems like Smart-L will locate the F-35. So will modern Russian and Chinese systems that are on the market today. I suspect the even bigger elephant in the room is IRST and other OLS like technologies. Because of the powerfull engine and other thermal problems wiht the F-35 it lights up on the sky. If so it will be detectable by other fighters and other passive groundsystems from far away. If this is the case then the whole F-35 programm is even more in danger of being cancelled.
Vince:
Exactly.
However, don't even need to go there since the issues and problems of the visible and observable vortex shedding (VOVS) relegate the JSF to the observable aircraft category.
Then there are the wake vortex encounter (WVE) problems which are an air safety issue.
However, inter alia, notice the US Senate Report talks about EW problems with one aperture.
Given the history and recent reporting, no cupid doll for figuring out which aperture that is.
VR,
Horde
wow.. air safety issue for flying through someones wake...
clutching at straws does come to mind.
If only stealth was categorical.
The jetwash behind the JSF is the worst ever experienced behind any fighter.
Someone obviously doesn't understand what happens to the pitot static and inertial platform inputs of a highly integrated DFCS when the aircraft it is flying hits such a wake.
Also interesting that JSF advocates ignore Horde's other point:
"However, don't even need to go there since the issues and problems of the visible and observable vortex shedding (VOVS) relegate the JSF to the observable aircraft category."
Those two brite white pointers in the sky are a good way to spot where the JSF is.
BZ,
Dan the Man
Dan.
Why dont you tell me how many FA/18's or other FBW aircraft for that matter have been lost as a direct result of Jet wash affecting their DFCS.
No they just run out of airframe hours before a replacement arrives.
Vortex trails are not persistent. If you can see them you're too close for stealth to matter (WVR).
I am not sold on the Joint Strike Fighter by any means but come up With a real argument please.
At what distance can the vapour trails of a B747-400 be detected?
Disappointingly, the VOVS coming off the outlier JSF designs are more powerful than those shed by such heavies.
As those who know will recall, according to Prandtl circulation and lifting line theory, one of the primary drivers of wing tip vortice circulation is the wing span loading.
Sorry, anonymous-who-ever-you-are, no cupid doll for you.
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For those interested in the numbers, the circulation in wing tip vortices trailing behind and persistent for more than 5 nm behind a B747-400 is somewhat less than 100 m^2/s.
Notwithstanding in-flight measurement would be the way to go to scope the size of the JSF VOVS issues and problems, the circulation in the vortices trailing behind and pointing back to these jets is likely somewhere north of 150 m^2/s!
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BTW, by definition, the JSF vortex trails are persistent and when not visible are still detectable by remote sensing devices tuned to the non optical bandwidths.
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Every jet can put a visible vortex out there when under load. Duh. The visible condensation vortex is transient. If the airplane is maneuvering or heavy and slow they will appear under proper atmospheric conditions. This is not unique to the JSF.
The difference is that the JSF designs are such outliers that the VOVS from these jets, particularly the alpha and bravo, is there in plain sight even in straight 1g flight.
Now that is anything but normal for a fighter which is supposed to have a combat wing loading around 50 psf, like the F-22A, Su-35S, T-50 PAK-FA and , now, the Chengdu J-20, all of which can do things in the air that the JSF acolytes can only make unsupported assertions about.
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As for being transient, is that like the concurrenc/commonality issues and problems inherent in the JSF aircraft designs only being "a transient"?
As you say, "Duh!".
Slow and heavy at one-G is all it takes for any airplane to produce them.
I am no fan of the JSF. I would rather just buy as many (which isn't much right now) F-15/F-22 as our budget allows with the money saved by canceling this program.
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