All Things Stealth

[Daan]

The Chinese workmanship on their J-20s seems markedly better than that of the Russians:

[DB]

19 hours ago, bojan said:

Why don't you like cross-head screws?

(Hint - I know the answer).

Just to be clear, I never thought that they were wood screws. 

With a bit more time to think about why they're used, I can think of a couple of reasons.

The first is that they are probably better for countersinking, which is probably necessary to get a flush fit in thin plate materials.

The second is that, like so many aviation things, approvals and certifications would be needed for a new fastener type and if all it did was allow faster assembly with less risk of damage to the fastener, then the benefits aren't worth the cost of approval.

[bojan]

Quote

The second is that, like so many aviation things, approvals and certifications would be needed for a new fastener type and if all it did was allow faster assembly with less risk of damage to the fastener, then the benefits aren't worth the cost of approval.

This might be it, economy of scale and approval process, those are used on practically every previous Soviet/Russian plane. Somewhere I have a few, if I find them I will take a photo. They have very, very good tolerances (more then my micrometer can measure), reason why I have spent two hours in the summer sun picking them from a MiG-21 at the scrapyard.

But there is a question - how do they solve a problem that crossheads can not be be torqued to the exact spec (yes, they can in theory, but tolerances are always quite big)?

Also for those breathless twatter hordes, B2 with screws just barely painted over (and paint pealing from others). Looks like those are hex key ones, so question is when did the US switch from crossheads to those?

Edited July 3, 2022 by bojan

[Stuart Galbraith]

If you look at those screws on the B2, some of the gaps and screw heads would appear to have RCS reducing putty in them. Some presumably dont, because why bother to keep maintaining it to that degree if you are just training. Which is entirely possible with the SU57 as well of course.

The B2 has a maintenance facility at its FOB at RAF Fairford, presumably with this in mind. I've read somewhere that the RCS of the B2 increases by nearly 50 percent if a bird craps on it in the wrong place.

 

[bfng3569]

On 6/25/2022 at 5:01 PM, bojan said:

MiG-21 and 29 used cross-head screws.

Re the pic, I think it is very early prototype in flight.

As for screws visible on stealth planes (cracking of coating is irrelevant to this):

They are also visible on F-35 if you can find a close-ups, painted over but still visible, but alas my google-fu is weak atm.

believe those pics of the F-22 are of the display team. 

[Josh]

On 7/3/2022 at 7:41 AM, bojan said:

This might be it, economy of scale and approval process, those are used on practically every previous Soviet/Russian plane. Somewhere I have a few, if I find them I will take a photo. They have very, very good tolerances (more then my micrometer can measure), reason why I have spent two hours in the summer sun picking them from a MiG-21 at the scrapyard.

But there is a question - how do they solve a problem that crossheads can not be be torqued to the exact spec (yes, they can in theory, but tolerances are always quite big)?

Also for those breathless twatter hordes, B2 with screws just barely painted over (and paint pealing from others). Looks like those are hex key ones, so question is when did the US switch from crossheads to those?

The B-2s are also practically made by hand, so I wouldn’t say they are good examples of US design, particularly anything current.

I don’t know enough about RCS reduction to have an informed opinion but the Su-57s main liability IMO is being outnumbered 100:1 by F-35, ignoring F-22s.

[bojan]

I don't "like" Su-57, but some of the arguments, like the one above using early prototype w/o paint as example for "it is  not stealth and it is crap" are more than a little over the top.

And guidable will lap that crap and spread it around like it is gold.

Edited July 4, 2022 by bojan

[bojan]

1 hour ago, bfng3569 said:

believe those pics of the F-22 are of the display team. 

Yes, but it can be clearly seen that screws are visible and not coated by RAM coating.

[lucklucky]

 

[Stuart Galbraith]

17 hours ago, Josh said:

The B-2s are also practically made by hand, so I wouldn’t say they are good examples of US design, particularly anything current.

I don’t know enough about RCS reduction to have an informed opinion but the Su-57s main liability IMO is being outnumbered 100:1 by F-35, ignoring F-22s.

The B2 was the first aircraft wholly designed by computer. The narrative is that the first one was built and all parts fitted without any modification the very first time. Which considering some bits were acquired from off the shelf is quite an achievement, and suggests very fine tolerances, far higher than the F117 was certainly was hand built.

 

 

[glenn239]

3 hours ago, lucklucky said:

 

Cool.  I did not know South Korea was even building an F-22 style fighter.

[urbanoid]

Given how we're buying everything Korean now...

[bfng3569]

20 hours ago, bojan said:

Yes, but it can be clearly seen that screws are visible and not coated by RAM coating.

It's the display team, from my understanding (and i think it was mentioned in the article that featured the photos from the WarZone) they planes for the display team do not keep the stealth coatings maintained the same as a regular service aircraft.

they aren't going to waste their time with the RAM coatings for screws for planes doing the airshow circuit.

[DB]

On 7/5/2022 at 2:22 PM, Stuart Galbraith said:

The B2 was the first aircraft wholly designed by computer. The narrative is that the first one was built and all parts fitted without any modification the very first time. Which considering some bits were acquired from off the shelf is quite an achievement, and suggests very fine tolerances, far higher than the F117 was certainly was hand built.

 

 

Actually, it could mean the exact opposite. A wide range of allowed measurements that fit without needing fettling.

Consider the era where mass car manufacturing could not match hand-crafted bodywork standards, and yet the cars just fitted together. The quality only really overtook hand-fitting for the average car in about the mid 1980s, I would guess, although the Japanese were probably a little earlier.

 

[Stuart Galbraith]

 

[lucklucky]

https://en.yna.co.kr/view/AEN20220719004500325

[lucklucky]

 

[Stuart Galbraith]

 

[lucklucky]

It appears to me a lot of European countries are thinking that buying F-35 is also buying USA protection.

[Stuart Galbraith]

Doesn't bode well for Dassault or BAE does it?

[TrustMe]

2 hours ago, lucklucky said:

It appears to me a lot of European countries are thinking that buying F-35 is also buying USA protection.

It's not that. It's simply that the US is so far ahead of the European aircraft company's that they cannot compete.

[lucklucky]

Far ahead in what? I don't see how F-35 have much stealth advantage that can change things.

[TrustMe]

I meant in technology. The only reason why countries buy non-US is for protection, or wanting to have several countries in the supply chain to ensure that one will remain open or that the US won't sell them more modern equipment.

The idea behind stealth is not simply that they can avoid enemy radar.

They also do not need lots of specialized support aircraft to accomplish a goal. If you look at operation Desert Storm, the F117 flew without Compass Call support ( to jam ground CGI ) EW aircraft and AWACS support. All expensive and vulnerable platforms that are no longer needed. 

Now that the US is selling stealth aircraft left right and centre to smaller air forces, they can now function just like the US did 30 years ago without all these specialised aircraft hence the air force is much efficent.

 

 

Edited July 20, 2022 by TrustMe

[Josh]

There's a lot more to F-35 than a low RCS. It's basically an out of the box SEAD/ECR aircraft, so there's a lot of value to it outside it just being a fighter. It currently is expensive in terms of per hour costs but compared to 4th generation a/c it doesn't have a significantly higher fly away cost. Another advantage is that the program is big enough and diverse enough that it will ultimately have a bewildering number of weapons integrated into it, as well as a constant stream of software and even hardware updates seeing as how it is the mainstay of the US (and several other countries).

That said for the Czechs I would have though just buying out the Gripens would be preferred; they basically just need air policing not high end capability. Such a small purchase doesn't make sense to me when they have adequate planes now that have some life left in them.

[Stuart Galbraith]

I'm wondering if the ability to loft B61 is suddenly a pressing issue...