FBW@FBW: How do you suggest I read this graph, then? I really can’t make sense of the isoclines.
You have to look at the energy. The p’s go negative which shows instantaneous turn rate. The red circle that mig-31 put on the graph shows the sustained turn rate, the upper point on the graph is corner speed.
Edit- sorry Mig pointed that out in the above post. The F-16A would still be very competitive in STR with anything flying at FL150 and below.
FBWInst- the E-M diagrams are pretty clear. At 15,000 feet the F-16 does not reach 16 degrees per second STR. It just doesn’t. The flight manuals are all over the web, read them.
The F-16A Block 15- had a sustained turn rate of 14.2 degrees per second with 50% fuel at 15k. It has the best sustained turn rate of the F-16 blocks.
FBWFBW, ligthen up, it’s Friday evening in Europe!
N10, joke appreciated 🙂
Very light. It’s happy hour here. In any case, T-VIP isn’t American (I don’t think) so the whole America-stronk thing doesn’t make sense.
FBWNot at all because they can do 50° AoA
Way to interject again with irrelevance. The AoA discussion wasn’t a criticism of the Rafale, or even about the relative merits of such a capability.
Every design has strengths and weaknesses. Adults can converse without getting b*tthurt. I should say most can without breaking out jingoistic, national insults because they didn’t follow the topic.
FBWhttps://www.armed-services.senate.gov/imo/media/doc/Deptula_03-15-17.pdf
Future of all arms warfare- Gen. Deptula (Ret.)
” This vision will
enable more rapid and effective decisions at the tactical, operational, and strategic levels of war
and will provide us an operating advantage that will be difficult for any adversary to overcome.
Key capability development areas in the Air Force to achieve this kind of operating paradigm
include:
a. Data-to-Decision: The objective is to fuse data from cloud-based sensor-effector
networks into decision quality information for use at the tactical as well as operational levels of
war. Machine-to-machine automation will be integral to allow for the rapid turning of data into
information and knowledge to inform decision-making. Big data analytics; incorporation of allsource
information; and sensor-to-sensor cueing must become the norm, not the exception in
creating a combat cloud.
b. ISR Collect and Persistent ISR: These are capabilities that focus on multi-domain
alternatives for placing the right sensor in the right place at the right time.
c. Penetrating Counter-air (PCA): PCA maximizes tradeoffs between range, payload,
survivability, lethality, affordability, and supportability to achieve penetrating counter-air effects
in anti-access, area denial environments. Establish PCA as a network nodal element to relay data
from penetrating sensors enabling the employment of standoff or stand-in weapons.
d. Agile Communications: This is increase in the resiliency and adaptability of integrated
networks. Focus on responsive, adaptable network architectures with functionality across all
platforms, weapons, apertures, and waveforms operating in a highly contested environment
FBWI’m confused on one hand some ppl praise the electronick attack capability of APG 81, but on the other side NGJ should equip F-35…
There currently aren’t any plans to equip the F-35 with NGJ. The USAF is studying a PEA capability for the late 2020’s. NGJ will be fielded with Mid-band capability only with low band added in increment 2.
http://www.dtic.mil/ndia/2014/PSAR/Croxson.pdf
FBWBelow 80 million in 2020 dollars? Given that they are talking about URF, but that will make it very hard to compete against the F-35 on price alone (O&S costs will become the next point of contention).
FBW“observed” without clue of fuel state or even accurate angle is worth squat
The only thing without a clue is your post. The “observed” was the sustained G based on the specification: 60% fuel with 2 AMRAAM, that was demonstrated in testing. This information and the link about the F-35’s observed air vehicle 240-3 configuration (vs threshold 4.6 g which you erroneously quote constantly as the sustained turn performance) has been posted here a dozen times at least.
No idea what you mean by accurate angle,
FBWThis guy…..*
So at the end, he talks about AIM-120 being heavier that of AIM-9’ish..
Yeah well how about you put on eight or even six AIM-120, and then give it a go :rolleyes:Guess that wouldn’t be fair eighter..
The turn rate is roughly 11 degrees per second at 15K (based on the 4.6g threshold and 4.95g observed 240-4 configuration test aircraft).
The rest? Who cares. That is an argument over at F-16.net between some Chinese poster using youtube to extrapolate J-20’s turn rate and a F-16.net member. I think there are enough arguments on here without importing them, you?
FBWI don’t think there is anything like “average Russian”.. the country’s income is very inequal and resembles United States while Canada is European-like in that regard.
Income equality or wealth equality? The U.S. has a serious wealth gap post 2008 recession as a combination of ineffective tax laws for accumulated wealth (real estate, capital gains), and increased savings as a result of post-recession investment jitters.
Income inequality in the U.S. is odd: pre-tax we have lower inequality than France, UK, etc. post-tax we have one of the highest in the world. Welcome to the wonderful world of the Byzantine tax laws of the U.S.
FBWUS is vastly, vastly more the “Likely Opponent” in Russian mil/political circles right now.
Let’s hope that that means in war gaming and the opfor in training.
Rhetoric is dangerous on both sides. Sometimes I wonder if the lessons of the Cold War have been forgotten.
FBWA good overview of the history of canards and high AoA tendencies (only a brief mention of Jas-39)
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870013196.pdf
Addition- @Obligatory
The JAS 39 Gripen is an aerodynamic statically
unstable aircraft in the pitch axis at subsonic speeds
with a time to double amplitude of approximately 0.4
seconds.
-that has nothing to do with (controlled) pitch rate. All longitudinally unstable designs oscillate, they pitch up (negative static stability), that is why they have FCS.
FBWerrr, “the aircraft could be “parked” at 70 to 80 degrees of alpha. ” (parked as in, controlled flight, indefinitely)
why would it have issues doing 50 aoa ? other than the fact that it slow the fighter down, that is
To reiterate for those who still haven’t grasped the concept- at high AoA the control surfaces on the tail are blocked from airflow by the fuselage. Modern fighters have leading edge devices that can generate strong vortices. Twin tail aircraft can still maintain control at very high AoA due to the tails. Single vertical stabilizer aircraft lose yaw control when the tail does not interact with the vortices. Same is true with the stabilator though many modern fighter use large horizontal stabs so they they do not lose pitch authority at higher AoA.
There is a drawback to twin tails; high buffeting at elevated angles of attack, added weight from both the twin tails and the fact that the tails have to be strong. As a result twin tails such as the Mig-29, F-15, F-18 (and according to testing, the F-35) often suffer fatigue in the vertical stabs. No free ride.
Examples:
Here you see the F-18 at high alpha with vortex coming of leading edge hitting the vertical stabs:
[ATTACH=CONFIG]252039[/ATTACH]
another:
[ATTACH=CONFIG]252038[/ATTACH]
Here is an F-16 at high alpha (notice the tail and vortex coming of leading edge):
[ATTACH=CONFIG]252036[/ATTACH]
here is the X-31 (single tail- with TVC to control yaw and pitch):
[ATTACH=CONFIG]252037[/ATTACH]
From the NASA X-31 study:
They recognized
that, when flying in this very slow post-stall regime, the effectiveness of
pure aerodynamic controls is limited, but that it was possible to minimize the
adverse aerodynamics to ameliorate the issue. But they also realized that additional
control would be needed. One possible solution was to employ thrust
vectoring of the engine exhaust to provide sufficient forces and moments to
control the aircraft
– https://www.nasa.gov/sites/default/files/files/Flying_Beyond_the_Stall.pdf
So, no the Gripen is not in controlled flight at very high AoA, without TVC it wouldn’t be able to (same as F-16, Typhoon, etc.) The canards help make it safe to exceed the control authority of the tail as they aid with recovery, as the quote in the Rafale thread stated.
FBWPushing past the soft stop may give higher AoA and more “g” above corner speed, does not mean 12g is available. It’s whatever the max AoA allowed by the FCS within a given loadout and configuration. Assuming the aircraft is clean (I don’t know if the Gripen is 9g capable with full fuel), then according to the above excerpt, then the FCS seems to allow for momentary excess g up to 12.
The corner speed is 323 knots, pretty good (assuming it’s at 15,000 feet). The F-16’s is around 340-350 knots.
FBWAbout the first part, I can only tell you also in all seriousness that I and the so called Sputnik have not any relationship of sort, for the rest I know you were joking as soon as you has not even taken the time of reading my post and so to not mistook what I said about F-117 (or B-2, or X-47) FLIGHT PERFORMANCES with its own level of stealth (that’s is still better than the ones of F-22 and F-35, it seems).
I read it, hence my reply. Advances in radar technology don’t negate the requirement for RF low observability, there is no magic wand that would make detection assured (or RF stealth assured for that matter).
, please let’s get a look what are being said in this same forum about GaN AESA, Photonic Radar and Software defined radio emission to get just a glimpse to what will be introduced in the field of radars in the next 5-10 years instead of basing yourself just on LM, Boeing and/or Raytheon advertising brochures please (joking as well).
We have all read about the development of GaN TRM technology, low frequency radar, etc. Speaking of advertising brochures, the detection ranges and sensitivity are based on ideal scenarios. Photonic radar has just been proven feasible in prototype form. That is a long way from becoming a weaponized, fielded system. GaN is also not some magical material. According to the director of one of the industry leading foundries (link in AESA thread), the GaN on SiC wafer TRM technology offers about 50% greater detection range based on then fielded GaA modules (not the outlandish numbers claimed by some). Newer GaA on SiC TRM have improved the power of current AESA, the currently fielded technology has not stood still while the industry transitions to GaN.
A lot of these defense articles and assumptions on this forum are based on certain fallacies:
1. RF low observability attempt to make the aircraft “invisible”. This was the result of the ill-informed press articles post- desert storm. The goal is to reduce detection range, shrink the engagement zone (therefore reaction time), break the kill chain.
2. “stealth” relies on RF and IR low observability alone; not true since the F-117 retired. Current aircraft have sophisticated threat detection IDAS (AN/ALR-94, AN/ASQ-239, etc.) The pilot is show the signal strength, optimal flight path, probably detection range, threat I.D. within the threat database. These aircraft carry countermeasures, even towed decoys in the case of the F-35. They have EA capability (we know the APG-77, APG-81 have x-band jamming, what isn’t open source is the full spectrum of capability provided by former and latter systems).
3. Radar advances will yield diminishing returns for LO. To a degree this is true, there is a limit to how cost, physics, aerodynamics will interplay in the drive to lower detection ranges. The error is assuming that radars operate in a vaccum of perfect atmospheric and combat environment conditions. It isn’t just a flight of LO aircraft vs. an advanced phased array and SAMs. Radar has to deal with real atmospheric conditions, a degraded electronic environment, decoys, EA assets, stand-off missiles attempting to break the kill chain.
For the second part you are confirming exactly what I have said: they have a precise idea of where they want to arrive (and that IMHO is just deadly wrong the same) but they have nothing other than vague clues of what they would need to get there.
You know, when you have not even the idea of not just the speed or the cost but even of the size or the same general form it will have it means you are not even started , so according of what you say we just know it would be LO and it will fly, all the rest is still in the mind of God.
I think you misunderstood what I was saying here. The PCA timeline suggests the program will be using relatively mature technology, TRL level 4 or 5 (even 6 in the case of the engine technology), and leveraging technology from the B-21.
There are design trade-offs: sizing, fuel fraction/range, L/D wetted area trade-offs, payload, airfoil and maneuverability, and of course LO considerations (short list). Finding the sweet spot in these design trade-offs is impacted by capability, cost, time.
The USAF knows it wants greater range, speed persistence. Hence the AETP and ADVENT engine programs. At this stage, both GE and P&W are in the process of developing the engine that will power future designs (and possibly current). As the process goes forward, the specification (one engine vs two, scale up or down the 45,000 lb thrust class planned for AETP technology, etc will be set.
The requirement for maneuverability will be based on the assessment of PCA study in 2017. The USAF had an AOA study in 2010 for a new air superiority aircraft, and will proceed with the PCA analysis of alternatives this year. It may end up requiring a very agile platform, which would impact LO considerations, size, fuel fraction, on and on. They may decide that having a 9g platform is less important for the air dominance mission compared to speed, LO, range. That is why they are doing the study.
In other words, none of this is in “the mind of god”. They’ve done previous AOA under NGAD, they’ve started the engine program, they are embarking on the current PCA AOA. You can be assured they have a good idea of what capabilities they want. The question will be what emerges from the design trade-offs and what can be accomplished within the budget and time frame.
You can search back in this thread and in B-I-O’s “rise of the sixth generation fighter” thread for what the USAF has been saying, and especially about the adaptive engine technology. They are not starting with a blank sheet of paper.
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