F-16 reversal pirouette?
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I have some history breaking things the skunks built, alamogordo says hello, here’s trying.
f-14 has same basic design protection by engineering the airflow to buffett around the edges of the flight window. With a little focus I think it’s possible. When I was flying a lot of Su-27 i was doing tail slides for practice, I vaguely remember pulling a hammerhead. The f-16 has a very strict roll behavior, it’s built well, it doesn’t want to be a flaming pile, but where there is a will there is a way.
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Let us know if you can do it. Im fairly sure its covered under ‘stuff the designers dont want you to do’ and under ‘stuff the designers tried really hard to prevent you from doing’ in the name of keeping the aircraft in a controllable condition.
Would be interesting to see if you can find a flaw in their FLCS protections
…which is another point my my continual “the book ain’t the end-all” comments…bang on the nose.
I’ve tried hammerheads and found that you can’t really do those very crisply either. The issue being that you don’t have enough rudder to get a crisp hammer head, and again the limiter hampers you in reaching/sustaining the vertical when you really need it. You also begin to lose some roll authority on the stick, if I recall…it’s been a while since I’ve played around with this. I also seem to recall that if you lead maneuvers that sometimes you can use the jet’s body inertias to “finish”, but it takes some real practice to be able to use that consistently.
You can generate a departure trying a hammerhead, though…if you really push trying. But what I have found is that controlling yaw induced roll at low speed isn’t really as difficult as some would have you believe, IF you ignore “conventional wisdom” about what people have to say about the ARI and FLCS washout(s). Rudder does work where I’d like it to work…it just doesn’t work to the extent I’d like it to work.
I’m sure there is some way to get the jet to reverse in a hurry…I’m thinking I just haven’t found it yet.
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keep cranking. we come up with new math using the same 9 digits all the time.
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It looks like the F35 can do its version of a pirouette also (though I don’t agree with the comments at the end of the video … seems like the F18 does a nice pirouette without thrust vectoring).
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I don’t know anything about F-35 flight controls, but I suspect that the F-35 is not AOA limited like the F-16 is…and that the twin rudders help. Much.
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without getting into the weeds. The f-35 has a reaction control system which uses compressed air to add super maneuverability in some aspects of flight, as well as to balance the aircraft. The f35 is covered with over 1000 points of thrust, it also carries a small amount of reaction thruster propellant. You didn’t hear it from me though
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I don’t know anything about F-35 flight controls, but I suspect that the F-35 is not AOA limited like the F-16 is…and that the twin rudders help. Much.
Will allow Max 50 degrees AoA in A-A config (Lockheed M)
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I DO know that only the V/STOL F-35B model (got to look over one of those once) has reaction controls - not the USAF or USN jets…so it’s not a factor in/for this discussion. Not to mention that if it operates like the Harrier RCS it only operates in the V/STOL flight regime not up and away.
Which now makes me wonder if an F-35B can drop nozzles at any point in forward flight like a Harrier - known as “VIFF”-ing; Vector In Forward Flight. Which also has far less tactical application than one might think…
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I DO know that only the V/STOL F-35B model (got to look over one of those once) has reaction controls - not the USAF or USN jets…so it’s not a factor in/for this discussion. Not to mention that if it operates like the Harrier RCS it only operates in the V/STOL flight regime not up and away.
Which now makes me wonder if an F-35B can drop nozzles at any point in forward flight like a Harrier - known as “VIFF”-ing; Vector In Forward Flight. Which also has far less tactical application than one might think…
thats not correct. Look up luke airforce base unrestricted maneuvers f35a panther demo team. that’s just the beginning.
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I don’t trust anyone’s ability to gather data from the public sector so I’ll just leave this here.
https://www.instagram.com/p/BsdJQSCHbqf/?utm_source=ig_embed&utm_medium=loading
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meanwhile at the skunkwerks
“jimmy pour some more 115 on this magnetic coil and back up a bit”
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Beautiful, pure aero.
I always look at TVC as ‘cheating’ to be honest (I use that term loosely of course).
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thats not correct. Look up luke airforce base unrestricted maneuvers f35a panther demo team. that’s just the beginning.
I’m not saying it can’t do the maneuver - I’m saying it doesn’t have an RCS. Only the B model has reaction controls.
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Beautiful, pure aero.
I always look at TVC as ‘cheating’ to be honest (I use that term loosely of course).
I see a lot of comments that this actually is TVC but that would be weird for a USAF F35A wouldn’t it?
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@TwanV:
I see a lot of comments that this actually is TVC but that would be weird for a USAF F35A wouldn’t it?
Yes, it would actually be very weird of all models.
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I have some history breaking things the skunks built, here’s trying.
The skunks (assuming you are referring to the (in)famous Skunkworks did not build the F-16, to be fair. Its LM now, but it was GD that built it.
f-14 has same basic design protection by engineering the airflow to buffett around the edges of the flight window. With a little focus I think it’s possible.
As I said, I wish you luck. Have you had any, as yet?
This would be the first Id heard of the F-14 having the same design(s) as the F-16. I guess they both have two wings and three wheels, though.
The f-16 has a very strict roll behavior, it’s built well, but where there is a will there is a way.
It is indeed pretty strict. Id recommend starting your efforts looking into the theory behind it, but I doubt that recommendation will be heeded. So instead Id love to see video of your efforts
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Hi Bluewolf,
what I was referring to within the design philosophy of the tomcat was the doctrine gruman took around departures. To expound on it here would muddy the waters, but in short, the aircraft was designed to buffett and level itself out much like an FLCS would do however this was simply done with the geometry of the airframe, and somewhat to a fault as can be observed in the inverted behaviors of the vertical stabilizer being blocked from airflow. this was considered a design balance for safety.
My lineal procession through this “hobby” comes from an industrial interest, and that is all I will say. To the point at hand, I will not waist my aging wrist doing the public disclosure dance but if you disbelieve your own eyes, so be it. I’ll simply wait for the pilots and the youtube videos to create the preponderance of evidence in the public sphere.
At very low speeds the viper is useless, I do not envisage the pirouette being something you would want to rely on, I wouldn’t want to get into an energy fight in the vertical in the viper, the horizontal is the place to win. I’ve had some luck with a tail slide but as far as an out and out hammerhead I don’t think it is in the cards. In the threat environment of twin engine and thrust to weight much greater than the viper to pull into the vertical in a gun fight would be an eventual losing decision unless you have a solution available immediately. the rolling scissor and the low yo yo seem to be the best bet, even further in that if someone tries to crank with you into the split they are going to come up snake eyes on energy and cannot out turn the viper.
I’ve only been caught slipping once in my BMS flying career by a su-27 all by his lonesome came in high on my five oclock I saw him shooting over my canopy, I just used a scissor reversal in the horizontal and he was dead in one turn. If you always fight down hill and use your AWACS you should never get caught out. As I fly i test the rudder response of the aircraft and as expected it quickly just ellopes rudder input into roll programs, thats the FLCS. with one vertical stabilizer and one point of specific impulse and that type of roll authority I do not foresee much usefulness or success in that type of maneuver.
For certain, to see the f35 performing above public expectation will be an ongoing trend as the years pass by. You always tell everyone your sword is blunt, underestimation is a weapon.
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I have heard similar things about “RCS” on conventional fighters from a fellow on the X-Plane forums a few years back. Does this just really amount to modifications to blown flaps / boundary layer control or the like? I would find that plausible, and likely why people do not notice it on conventional aircraft. In contrast, traditional RCS on fighters tends to resemble the other RCS we notice: thrusters on spacecraft. Only the '35B has the latter (traditional RCS, that is), though it is covered by louvers when not in use. The Harrier’s RCS thrusters hang out for all the world to see. These aircraft need very powerful forces exit the airframe for control at low airspeeds, and so tiny thruster points just won’t happen, and therefore are quite noticeable.
…If this RCS you mention is present on the '35A and 'C, I have to believe it is more akin to a “Combat BLC” system than anything common to the F-35B.
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No. No even close to blown flaps. The Harrier (being the best and with which I am most familiar - other successful V/STOL jets are of similar design/function) has actual reaction jets powered by engine bleed air at it’s wing tips (roll puffers), in the “stinger” aft of the rudder (yaw puffer), and under the chin below the nose (pitch puffer). The bleed air ducts are only pressurized at certain nozzle angles and the puffers are coupled directly to the stick and rudder - they all partially open/close with pilot input, but for pure wingborn flight (nozzles aft) no air moves through them, as robbing bleed air for power robs the engine of overall “forward” thrust available.
These “reaction controls” operate just like the thrusters on a spacecraft - they expel jets of air that push the airframe around and either augment or provide full authority control power, like during hover. Only the V/STOL variant of the F-35 - the F-35B for the USMC and Royal Navy - have this system. The USAF (F-35A) and USN (F-35C) jets DO NOT have reaction controls (and I can think of many reasons why I wouldn’t want them there, as a designer). I think they may have thrust vectoring, though…which is not the same thing.
BTW - blowing hot air all over your airframe just make you look that much more tasty to a heat seeker. So nobody does that. Not on fighters, anyway.
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Hi Bluewolf,
To the point at hand, I will not waist my aging wrist doing the public disclosure dance but if you disbelieve your own eyes, so be it. I’ll simply wait for the pilots and the youtube videos to create the preponderance of evidence in the public sphere.
I must be confused as I confess I dont see how that relates to the point at hand… you think F-16 pilots are likely to create a preponderance of evidence that the FLCS can be worked around? This seems unlikely to me, but then as youve implied a few times over the last few weeks, you have access to information not public. I can only assume its a new job you are proud of. Go you!
At very low speeds the viper is useless, I do not envisage the pirouette being something you would want to rely on, I wouldn’t want to get into an energy fight in the vertical in the viper, the horizontal is the place to win. I’ve had some luck with a tail slide but as far as an out and out hammerhead I don’t think it is in the cards. In the threat environment of twin engine and thrust to weight much greater than the viper to pull into the vertical in a gun fight would be an eventual losing decision unless you have a solution available immediately.
Fortunately, there are not so many aircraft around that fit that description. And of the aircraft that do, there arent very many of them built. And out of those, fortunately many of those aircraft are flying only in US forces.
I’ve only been caught slipping once in my BMS flying career by a su-27 all by his lonesome came in high on my five oclock I saw him shooting over my canopy, I just used a scissor reversal in the horizontal and he was dead in one turn. If you always fight down hill and use your AWACS you should never get caught out. As I fly i test the rudder response of the aircraft and as expected it quickly just ellopes rudder input into roll programs, thats the FLCS. with one vertical stabilizer and one point of specific impulse and that type of roll authority I do not foresee much usefulness or success in that type of maneuver.
Im unused to measuring specific impulse in ‘points’. Im more used to units of seconds, for Isp.
As Mav has done an excellent job explaining in the Dark Side of the FLCS article, the F-16 is designed to roll around its velocity vector rather than its longitudinal axis. The intention is to avoid a coupling between angle of attack and sideslip, where an excess sideslip is converted to angle of attack by rolling the aircraft. To achieve this, the aircraft tries to zero its sideslip in the roll, with the ARI.
As the pilot inputs could cause significant loss of stability in this regime, pilot pedal authority is faded out with increasing roll rate and angle of attack. If you have angle of attack, or if you have roll rate, or some combination thereof, you have reduced (possibly zero) rudder authority.
An easy proof is to do the rudder authority demo, from the AHC series of exercises (intended for real world viper studs). 250 KCAS, trim for 1G. Select IDLE power, release the stick. Aircraft will maintain level flight until about 15° angle of attack. You’ll see the nose start to drop at 15° AoA, so grab the stick and start adding back pressure, just sufficient to maintain level flight. You’ll find, as the aircraft slows down, that you reach full aft stick to maintain level flight as the aircraft reaches about 25° AoA. At that point, with IDLE power still, and full aft stick, you will still see the nose lower. If you go to an external view, you will see the elevators are NOT fully deflected trailing edge up as they would be in a conventional aircraft, but are lowering the lose to maintain the alpha limiter. Hold full aft stick to maintain the limiter, then kick the rudder pedals - on the limiter, zero authority. Just off the limiter, you will find slight rudder input. Also note with full aft stick and AoA on the limiter, that you still have roll control, and no risk of a wing drop (as the aircraft is nowhere near the stall). You should be able to get around 80°/s roll rate - with zero rudder authority above 30°/s roll rate.
If you try to fly it like its a P-51, you wont be able to pull off the stuff it can excel at - but you also shouldnt kill yourself trying. If you try to fly it by just treating the controls as simple axes, like its a video game - then you should get excellent results. Keep your feet off the rudder.