i.e.Wrong again.
Its not specific to India lol its how flight testing is done.The FCS undergoes lot of changes including software even after the IOC and after that the full operational envelope is opened up.BEfore IOC its the test pilots who fly the aircraft whereas after IOC regular pilots can fly it too.
I know Indian guys think software is their forte, but I don’t think you want to lecture me about FCS software,
but if you insist…
if you take out 1 ton of weight out of an aircraft , FCS software has to be redone. and if you redesign you primary structure, looks like have to be for weigh issues, some of the critical stuff has to be changed.
at least some of your critical points and aeroservoelastic and closed loop flutter points has to be re-flown.
and if you are not lucky, some of your handling characteristic could change based on the critical stuff that is changed.
It is going to take a heck a lot of more flight test hours and $$$ than you imagined.
i.e.my point of referene on IOCs.
at least the projects I have seen,
at point of IOC the customer has agreed that most of aircraft’s critical performance parameters are met. and those that are left can be reasonably be assured that the program can deliver.
as an outsider looking in, no, I can’t be assured at this point that rest of the package can be delivered. either by tract record or the technical merit shown so far. may be they can , may be they can’t. I will believe when that’s delivered.
Also.
Even if we overlook the superiority in mission avionics, Gripen is vastly more mature airplane than either Tejas or Thunder. maturity in aerospace/defense accounts for a lot. IMHO
i.e.Which proves that indeed you have no idea about flight testing and IOC at all.
your statement is partially correct, and allow me to qualify it:
I really ‘have no ideal about how Indian Military aviation organizations conduct flight testing and IOC at all”
btw,
you are just throwing personal attacks at this point.
i.e.Since when has opening of maximum flight envelope necessary for IOC??Do you have any idea about flight testing??There is something called a baseline flight envelope.In most cases the maximum flight envelope is not achieved at IOC.
which means IOC is pretty meaningless wrt the development or technical merit of the airplane.
i.e.if so, what are you ranting about ?
LCA is comparable to gripen because it IS comparable to gripen, not because of when it reached IOC. that has as much relevance as you flaming on this forum.
you can compare those two airplanes side by side.
yes.
But comparable is an adjective that has a different connotation than the act of comparison itself.
and I would not put comparable to describe these two airplanes. same class based on engine and MTOW, may be yes, Comparable? no.
i.e.yeah lol, you are talking about the gripen right ? the fighter that was inducted into the air force and declared a stunning success even before it achieved IOC ?
…and therefore because of that IOC sticker was applied on LCA BEFORE it is inducted and declared a stunning success, so it is comparable or better to gripen?
what is IOC and inducted to AF anyways.
those are stickers/labels, it is a technically meaningless checkbox for public consumption and bureaucratic tidiness. it has nothing to do with technical merit.
i.e.Yes, and whatever reason it was, it wasn’t lack of flight performance.
A contributing factor was the weird phenomena where one of the largest countries in the world would rely on a tiny country no-one heard of for the mainstay of their air force i guess.
yeah….LOL
when one of your prototypes has yet to pull max-G and alpha and it is already declared a shining success and IOC, it does make one wonder does it?
i.e.Look at the world map, Indonesia needs fighters that have long-range and strong anti-ship capability.
It’s more like to say: hi, I’m a peaceful country.:)And measure the Korean peninsula, F/A-50 is the perfect choice for South Korea.
Su-30 MK2 😉
But they also need COIN and some overbuilt hot rod for their pilots to tool around burning hours with guns and rockets and keep current.
i.e.Do You know when the J-10 were transfereed ??? As far as I remember that was quite early ??!!
I am not good with dates.
If I can remember correctly.
CFTE has the full-up telemetry required to do some of these more data-driven high risk test points. and they built up the facilities , partly on J-10 project , specifically for flight test modeled on Edwards (and partly Zhukovsky). CFTE was formerly the Lanzhou Military District Unit 929.
…
actually right now in my hand is a text book on flight testing engineering written by CFTE former vice director Zhou ZiQuan.
He was the Chief Flight Test Engineer for J-10.
but as far as organization is concerned he was always part of CFTE Organization. Before that he was also the chief designer for K-8V IFSTA AND BW-1…note those project are not led by CAC.
anyways,
the name of the text book is “Flight Test Engineering” (in Chinese of course) . It’s good alot of good bits of historical data and insights…methodology is very current, execellent book if anyone happen to come across it.
.
i.e.I don’t think so, CFTE only tests full state products, not experimental products.
hogwash.
every developmental civil or military aircraft in Chinese governmental related aeronautical industry has gone through CFTE at one point or the another.
the J-20 prototypes will move on to CFTE at one point or another.
CAC field and airspace is inadequate to meet the full range of flight tests required by either for PLA Accepetance or CAAC-CAR requirements.
i.e.Haha, what you say is generally true i.e. A flat winglet however is effectively an extension of the wing which does help with L/D as you rightly point out by increasing AR. The major issue here from an airliners point of view isn’t actually structural – its regulatory – from a structural point of view we could be building high aspect ratio airliner wings with AR > 12 quite feasibly. The big issue with this is of course the span which breaks airport compatibility limits. IIRC looking at the Dreamliner with its winglets – I think it barely manages ICAO Code ‘D’. So winglets help cheat span issues – not just structural but also and mainly – regulatory.
Or if we are brave and perhaps clever as designers – to truly alleviate huge root bending moments and radically increase AR at the same time – we should look to my favourite idea – which is a strut braced wing. Similar to a Cessna but taking it into the world of transonic drag – which is the major issue. The acute angle between strut and wing produces a choking effect and lowers aircraft crit mach significantly – although work is currently underway at a few institutions – including mine to work around this.
what you said is generally true.
rumor has it that one version of 777 would have a outerspan that is foldable to get into some tight gates. at the request of some big customers. at cost of mechanisms and some weight penalty, but everyone wised up and decided against it at last minute.
and there are other airplanes that comes with some very artificial span limits, like get into certain hangars and etc.
but generally speaking you can work with chord to get a higher AR wing, but ofcourse there are considerations.
and believe it or not one big trade points FOR a under wing mounted engine is for loads, at cost of a bigger empennages for engine out.
anyways, your strut braced wing would be a good idea, except those problem you mentioned AND that a high aspect ratio wing is bit volumn limited… If you want to put leading edge de-icer, flaps, control surface, fuel systems, etc etc on/in it, things that you need to make a real airplane, you would find that it wouldn’t be as nice any more.
also what is the stall speeds and behavior for these long yard stick wings? first wing bending mode I would imagine would be pretty low eh? what would be ramification for that?
what is the usable fuel volumn in the wing? that’s not a really laughing matter,
for a ridiculously long AR braced wing to pay back all the efficiency gained in L/D, the cruise phrase needs to be pretty long.
that means fuel.
where is the volumn coming from if you can’t put in the wing? put it in the fuselage? helo increase wing root bending.
btw, have you noticed boeing has been going more and more towards a big-wing-with-simple-single-slot-flaps? 787? why huh? you asked?
turns out in trade studies the big engine big wing in a climb is where you get most benefits for the airlines. also noise is a big stickler.
can’t look at these things in isolations, at least we can’t afford to in real world outside of academia. 😉
i.e.For those even lower on budget there are used mig-29’s. The countries that need basic features for their aircrafts, especially to replace ancient planes tend to go for advanced trainer.
to be fair to Tejas and FC-1, they are a wee bit more of a fighter than T-50. Btw why don’t you go on a full offensive and include older model Gripen in the fray too :p :diablo:
don’t forget those J-7MG and J-7Es
:diablo:
can’t discount those goodie oldie hotrods.
armed with good IR-AAMs they are pretty good bangs for the buck.
i.e.I.e. I would speculate that the main reason the F-16 carries AMRAAM on its wingtips is that it reduces spanwise flow and as a result reduces vortex induced drag (drag due to lift) – in a similar manner to a winglet on an airliner.
you can stroll around F-16.net and find out what they really are for.
as to winglets,
Think about it this way, what’s the best dihedral angle for winglet?
flat and become part of the wing of course!
a bigger aspect ratio would always, always, always get you better L/D.
so why doesn’t airliners etc have flat winglets?
ah, it turns out a bigger aspect ratio wing would increase your wing root bending moment… key indicator of structure fatique and loads.
increase loads = increase structure = increase mass.
by having mass in outer span, the total load on the wing is the same… the wing would still carry the same weight, but the wing root bending moment is smaller now.
so there is always a trade. 😉
( btw, a true loads/structure experts can correct me, I do not pretend to know all about this stuff )
i.e.First jet aircraft were fighters designed to intercept high altitude flying bombers and dogfight other jet fighter with a gun.
First missiles were unguided rocket flying straight foward (try to put these in a internal bay door !), then guided missile with IR or EM seekers that had to lock on their target before been launch (again try to put these in internal bay).
Then the design of the first jet fighters, very light with the air entry right in the nose of the aircraft…
Bombers, kept their bombs internal even with the introduction of jet powered engines.Then you have the fighter-bomber that was used during WW2. They had their bombs outside their fuselage because they were call dive bomber (again try to dive bomb somthing with internal bay door).
When they were equiped with jet engine their kept their tactics of dive bombing thing of the ground.Since WW1 every long range aircraft carries its weapons internally. The way todays fighter/bomber carry their weapons is the compromise (since they no longer have to dive).
And with composite materials, bay doors are no longer necessarily heavy.
So I’m not saying that a aircraft has to carry its weapon internally, but yes it can provide huge advantages (less stress during long range, high speed flight etc…).
And the way stealth is shaped today does help with aerodynamics (smooth surfaces…).
I am not saying it is always the case one way or the other, it all depends on individual trade.
Also, structure wise.
It is not just the door that is the dead weight.
for intenal carriage, the body needs an Internal structure that can harness the load, under gs., hopefully the configuration allows you to carry it on one of the main fueslage main structure frame. normally the highest loading frame (strongest) is the one that attaches wings to body. you want your bomb strap to that, but most of time because of configuration that’s not really possible. so extra structure has to be put in, structure that cost weight.
wing is already designed to carry alot of weight, acutally by carrying stores underneath the wing you are actually relieving the wing root bending moment… a big driver in loads thus weight. that’s also the reason why alot of fighter’s (including J-20’s long strut with its big side strut) MLG is attached to the wing/fuselage point….I digress.
ever wonder why late-model F-16s in services opted to carry AMRAAMs on the tip pylons? same reason.
anyways, again I am no expert.
i.e.Could advances in ECM/EW help to protect these LO targets, and are any such advances on the horizon/likely? I assume nations without LO aircraft would want to seek some way to protect their assets.
yeah I would a very cost effective solution would be to have a very capable AWACS system aircraft. or multiple sensor aircraft linked together to form a common picture.
datalink is getting better and cheaper every day. some of these COTS stuff is unbelievable.
also you can invest in some good jammers. sure.
my pet idea:
distribute your AWACS network into mutliple UAVs. datalink them to provide you with a resilient network.
forgo the active radar all together. fields lots of light, high performance, LO aircraft that essentially perform interceptor mission. with good datalink to that AWACSs net for long range cueing. and EO sensors for mid-range and close in fight.
develope MR-IR missiles to capitalize on advances in EO sensors. and short range close in fight IR missiles.
think of it as the LWF reborn.
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