see my reply in blue.

Because its a beast of burden meant to fill two rolls for a country that can no longer afford both a dedicated interceptor and a dog fighter.

so some sacrifice has to be made. heh?

That trick works for both sides. Lets pretend the F-22 has a max speed of M1.8 and the PAK-FA tops out at M2.2. Remove the safeties and you can push the F-22 probably to M2 and the PAK-FA maybe to M2.3, but the gap remains much the same. A max speed .3M better than the other guy is always a good thing to have.

agree in part, but, the point is always drag. you can push out your max speed but for how long. and in what turns. air combat is not speed race.

also do consider envelope. M2 at 60000ft is not same as M2 at 30000ft.

The supercruise ability of European 4.5 gens is basically BS and has little to do with their aerodynamics. The Su-35 supercruises too, but we still say its still optimized for transonic and low mach nose pointing — same goes for the Eurocanards. The reason the Eurocanards were supercruising 10 years sooner is simply because they had better engines available to them that much sooner. The basic Al-31 has been more than a bit dated since the early 90’s. It’s late 70’s engine tech and the Russians went the entire decade of the 1990’s without anything better.

Euro canards has their own issues. J-20 is not a euro canard by any strech of means.

Oh God saves us all. :diablo:

That must be why his work was being cited in an engineering text (written by an authority in the relevant field) I read in the first weeks of December.

Why can’t we just accept that Kopp has his ‘strong views’ in one particular area and leave it at that? As this forum too readily demonstrates, we all have out loveable (or unloveable) beliefs with which we bore our friends, but still may have much of value to contribute.

hmm read his background and papers. doesn’t seem to have any real aircraft program experience, study this think tanker that. dim a dozen around dc area.

I am sure he is a smart man. but…

He does have his strong views, and I have met many of them old-timers who has that, but one commands respect is when one still doesn’t deviate or bends from engineering discipline. a bit more piety before declare something.

Dr Kopp if you are reading, I am sorry if I have offended you. I have always enjoyed your site. and you have done some fine work.

Yes, correct.

My eyes, I’m getting old now lol. 🙂

I just purely guessing…

Gear Doors do flutter.

also bit of random thought.

any one notice the big washout on the big anhedral wings?reminds one of concorde’s wing?

couple that with the dihedral in the canards?

lateral stability might not be a big factor in those choices.

==========

Also,

they could make this really interesting by make a F/H-20…. think F/B-22.
it’s already huge. lot’s of room for gas and bombs.
No need for absurdly high AOA demands, thus LEVCONs are ok. new compound curve wing, optimized for high speed cruise.
all the system is paid for.
heck even lighten the structure much up by decrease max G-load requirement from +9.5 to +6.
go tailless if one is venturous enough…

instant strategic bomber.

Hi all,

watching this thing for a while, finally decided to comment :p
Couple of comments, then I will watch the fireworks. :p

1) This thing may have big (-10%Mac) negative static margin for transonic speeds. this also should help out with L/D at supercruise speeds.

2) for close coupled big canards/LEX/DeltaWing combo, 1+1+1 > 3. thus on the planeform side you may will see over all a smaller lifting surface (higher onpaper wing loading) than the other two.

3), comment 1)+2) should tells you bit about what the idea is for this design. longitudinal wise: try to get good nose pointing ability, good energy turns, and good cruise drag, at same time and affordable price.

4) On T-50: T-50’s wing-body design relies on channel flow between two big engine booms. not entirely with out problems, imho. draggy. the name of the game is always L/D and LEVCON is not necessarily better get your a better L/D. and it does have its drawbacks. and LEVCON certainly can not beat canards at high AOA nose down pitching moment generation.

5) DSI may not be that bad with supersonic pressure recovery, all depends on how you design it and where your critical speeds are.

6) This thing may well turn out to have distributed hydraulic/ EHAS.

7) ah those dreaded ventral fins. my guess is lateral stability at high aoa ( and high mach) may be border line with the two smallish VT when they did their tunnel and cfd studies. and the canards are naturally handicapped at providing enough rolling moment (main wing aileron is long gone) at extreme aoas. (see F-22’s famous paddle walk), thus they are out of options. now unless flight test turns out that that’s not critical or they are really going to get some good TVCs, fins are staying.

which are not necessarily excruciatingly good RCS reflectors…. certainly the much smaller all moving smaller VT helped balanced out the total side RCS budget.

over-all very nice job Mr. Yang Wei and Mr. Song. and all the hardworking folks at 611 and 132, hats off to you guys, merry christmas happy new year.

Now let’s see WS-15 is really what it touts itself to be. 😉