What is the pedal turn that generates a constant 28deg/sec?

Unread postPosted: 17 Nov 2016, 02:29
by gta4
Image

Even though F15 and F16 are generally considered better turning aircraft, it is still interesting that F35 won most of the two-circle turning fights (butterfly).

This is probably the reason:
Image

Imaging what would happen if your opponent could maintain a rate of turn that you could only reach momentarily...

Pilots describe this turn to be an abrupt pedal input during high AOA. It seems like a herbst-like or hammer head reversal. Is my understanding correct?

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 04:32
by spazsinbad
QUE? First missing picture is missing: http://bbs.webkx.net/forum.php?mod=atta ... update=yes

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 06:13
by garrya
Constant 28 degrees/second ???? whattt ??? for real ? :shock:

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 06:28
by optimist
this is where it came from, Personal interview with former F-16C pilot currently flying the F-35A, April 18, 2016.
http://www.heritage.org/research/report ... nt-process

The F-35A was not designed to be an air superiority fighter, but the pilots interviewed conveyed the picture of a jet that will more than hold its own in that environment—even with its current G and maneuver restrictions. In the words of an F-16C Weapons School Graduate and instructor pilot now flying the F-35A, “Even pre-IOC,[26] this jet has exceeded pilot expectations for dissimilar combat. (It is) G-limited now, but even with that, the pedal turns[27] are incredible and deliver a constant 28 degrees/second. When they open up the CLAW, and remove the (7) G-restrictions, this jet will be eye watering.”[28]

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 08:37
by charlielima223
garrya wrote:Constant 28 degrees/second ???? whattt ??? for real ? :shock:


That sounds pretty impressive but it makes me wonder about the conditions for it. Falling back on that infamous USAF Colonel talking about the Su-30MKI and F-22 he states that the F-22 can

and this is no sh*t, a 28 degrees per second turn radius at 20 thousand feet. The F-15 has an instantaneous of 21 and a sustained of about 15 to 16 degrees. The Raptor can sustain 28 degrees


Now I know the F-35 is maneuverable but it is commonly held fact/belief that the F-22 can dominate the F-35 in the kinematic arena. I am going to make a SWAG that the quoted 28 degrees per second for the F-35 at post stall maneuvering. F-22 on the other hand is said to sustain that BEFORE it goes into post stall maneuvers.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 11:36
by hornetfinn
Pedal turn as explained by Morten Hanche (Norwegian F-35 pilot)

https://nettsteder.regjeringen.no/kampf ... ed-so-far/

Defensive situations often result in high AOA and low airspeeds. At high AOA the F-16 reacts slowly when I move the stick sideways to roll the airplane. The best comparison I can think of is being at the helm of ship (without me really knowing what I am talking about – I’m not a sailor). Yet another quality of the F-35 becomes evident in this flight regime; using the rudder pedals I can command the nose of the airplane from side to side. The F-35 reacts quicker to my pedal inputs than the F-16 would at its maximum AOA (the F-16 would actually be out of control at this AOA). This gives me an alternate way of pointing the airplane where I need it to, in order to threaten an opponent. This «pedal turn» yields an impressive turn rate, even at low airspeeds. In a defensive situation, the «pedal turn» provides me the ability to rapidly neutralize a situation, or perhaps even reverse the roles entirely.


Basically it means pointint the nose of the aircraft during high AoA and low airspeed maneuvering. Basically a bit like handbrake turn with a car. AFAIK, large twin tail is really beneficial for this kind of maneuvering and I'm sure both F-22 and F-35 can do it very well as both have very large twin tail (and F-22 also has TVC).

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 14:23
by basher54321
charlielima223 wrote:
Now I know the F-35 is maneuverable but it is commonly held fact/belief that the F-22 can dominate the F-35 in the kinematic arena. I am going to make a SWAG that the quoted 28 degrees per second for the F-35 at post stall maneuvering. F-22 on the other hand is said to sustain that BEFORE it goes into post stall maneuvers.



Turn rate is normally associated with a bank angle and pulling back on the stick in a horizontal level turn only - that is what the ITR and STR figures are usually about - and they are normally quoted at higher speeds where a dogfight traditionally took place.
A pedal turn is a bit different and was also mentioned in the High AoA test report that everyone kicked off on (IIRC without looking) - where he mentioned it was better using pedals over a traditional turn when at very slow high Angle of Attack. So to me the 28dps rate would be generated in Yaw with not much in the way of bank - almost flat but with some pitch but at very slow speed.

Actually skidding car above that I didn't see might be better than my description to some extent.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 14:38
by gta4
Just asked one of my friend who is a flight control engineer. His explanation is interesting.

"At low AOA, rudder is responsible for yaw, while aileron is responsible for roll. Pedal input only causes rudder to deflect."

"But at high AOA it's the other way round. Rudder has more roll authority while aileron has more yaw authority. So at the presence of an abrupt pedal input, modern flight control software will interpret it as a yaw command and deflect both aileron and rudder, where most of the turning (yaw) torque is actually from the aileron. The rudder in this case is a stabilizer that prevent the aircraft from departure."

"F-35 has a very big aileron/wing area ratio. That is probably the reason for which it could generate so much turning torque, and to make that 28 deg/sec turn constant. Rudder can not make that rate sustainable because it loses controllability at high angle of sideslip."

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 14:48
by sprstdlyscottsmn
gta4 wrote:Just asked one of my friend who is a flight control engineer. His explanation is interesting.

"At low AOA, rudder is responsible for yaw, while aileron is responsible for roll. Pedal input only causes rudder to deflect."

"But at high AOA it's the other way round. Rudder has more roll authority while aileron has more roll authority. So at the presence of an abrupt pedal input, modern flight control software will interpret it as a yaw command and deflect both aileron and rudder, where most of the turning (yaw) torque is actually from the aileron. The rudder in this case is a stabilizer that prevent the aircraft from departure."

"F-35 has a very big aileron/wing area ratio. That is probably the reason for which it could generate so much turning torque, and to make that 28 deg/sec turn constant. Rudder can not make that rate sustainable because it loses controllability at high angle of sideslip."

Don't forget differential deflection of the massive Stabilators

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 14:55
by basher54321
gta4 wrote:Just asked one of my friend who is a flight control engineer. His explanation is interesting.

"At low AOA, rudder is responsible for yaw, while aileron is responsible for roll. Pedal input only causes rudder to deflect."

"But at high AOA it's the other way round. Rudder has more roll authority while aileron has more roll authority. So at the presence of an abrupt pedal input, modern flight control software will interpret it as a yaw command and deflect both aileron and rudder, where most of the turning (yaw) torque is actually from the aileron. The rudder in this case is a stabilizer that prevent the aircraft from departure."


Yes that sounds correct - traditionally in some older jets at low speeds with high AoA you had to manually press the rudder pedals to roll/bank it otherwise if you used the stick (ailerons) you got this effect called adverse Yaw that could cause a departure in cases ( quite a few F-4s over Nam were lost this way).

With an FLCS on the F-16/35 the computer takes the pedal input and does the work of moving the correct flight surfaces for the speed, A0A, bank, etc etc - not the pilot.
Obviously I don't know how the control system actually deals with this in the F-35 regarding the surfaces moved - but the end result sounds very much like a Yaw not a roll.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 16:21
by gta4
typo corrected:
"But at high AOA it's the other way round. Rudder has more roll authority while aileron has more yaw authority"

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 17 Nov 2016, 16:24
by gta4
sprstdlyscottsmn wrote:
gta4 wrote:Just asked one of my friend who is a flight control engineer. His explanation is interesting.

"At low AOA, rudder is responsible for yaw, while aileron is responsible for roll. Pedal input only causes rudder to deflect."

"But at high AOA it's the other way round. Rudder has more roll authority while aileron has more roll authority. So at the presence of an abrupt pedal input, modern flight control software will interpret it as a yaw command and deflect both aileron and rudder, where most of the turning (yaw) torque is actually from the aileron. The rudder in this case is a stabilizer that prevent the aircraft from departure."

"F-35 has a very big aileron/wing area ratio. That is probably the reason for which it could generate so much turning torque, and to make that 28 deg/sec turn constant. Rudder can not make that rate sustainable because it loses controllability at high angle of sideslip."

Don't forget differential deflection of the massive Stabilators


Yes that is a big factor

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 17:24
by mixelflick
gta4 wrote:Image

Even though F15 and F16 are generally considered better turning aircraft, it is still interesting that F35 won most of the two-circle turning fights (butterfly).

This is probably the reason:
Image

Imaging what would happen if your opponent could maintain a rate of turn that you could only reach momentarily...

Pilots describe this turn to be an abrupt pedal input during high AOA. It seems like a herbst-like or hammer head reversal. Is my understanding correct?


This is just HUGE...

If I were LM, I'd share this as far and wide as possible. These aren't people watching youtube videos, they're pilots who are inherently biased in favor of their current aircraft. It'll make a nice antidote to the "can't turn, can't turn, can't run"/APA's of the world..

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 18:30
by steve2267
gta4 wrote:Pilots describe this turn to be an abrupt pedal input during high AOA. It seems like a herbst-like or hammer head reversal. Is my understanding correct?


I started the F-35 FLCS CLAW design thread (viewtopic.php?f=60&t=52507) to make sure I understood the control laws before responding. Good thing I did, because I didn't have the correct understanding of the stick inputs. It was johnwill's reply that set off the lightbulbs:
johnwill wrote: Lateral stick force does command roll rate, not around the airplane roll axis, but around the airplane flight path axis. The difference between airplane axis and flight path axis is AoA.


After googling 'herbst maneuver' it appears that a post-stall high yo-yo might be one form of the "herbie". If you pull up into a high yo-yo but keep pulling until you get alpha well up over 30°, then as you continue to command roll you will roll around the flight path vector (not the aircraft longitudinal axis) which will be both a roll and yaw around the aircraft longitudinal (x) and yaw (z) axis. I think you will be performing a Herbst maneuver (J-turn). Now if you stomp on the rudders at the same time, you are really going to slew that sucker around. I could see where that 28°/sec comes from and really makes the F-35 dangerous close in. I wouldn't want to get slow and stay there, but if you've got the smash to get your speed back... yeah, they might be re-writing the book on knife fighting in a phone book.

After further research, it appears that the Herbst maneuver is also used in an offensive spiral.

Image
Image


The NASA F-18 HARV program in 1983 also seems relevant: https://www.nasa.gov/centers/dryden/his ... RV/rd.html


Image
Image
Image

I am reminded by something Dolbe Hanche said about how the F-35 brakes faster than a car. And johnwill mentioned that
johnwill wrote:Longitudinal stick force does command pitch rate under some conditions, but mostly it is g-command. It is called a blended pitch rate / g-command system.

So if your airspeed is too high such that when hauling back on the stick you are g-limited before generating high alpha, you probably have to dump speed before you can herbst around on the other guy's @ss.

If what I'm saying is correct, and you're in a Viper, say, trying to saddle up on an F-35, and he pulls up... and his flight control surfaces all go bat sh*t (speedbraking), that might be your clue to unload, hit the gas and try to get out of dodge in a hurry. Hopefully you can make it to the o'club without eating a slammer. But probably not.

This NASA links may be of additional interest:
https://www.nasa.gov/centers/dryden/mul ... 478-3.html

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 18:32
by sferrin
mixelflick wrote:If I were LM, I'd share this as far and wide as possible. These aren't people watching youtube videos, they're pilots who are inherently biased in favor of their current aircraft. It'll make a nice antidote to the "can't turn, can't turn, can't run"/APA's of the world..


And that's with jets that still aren't cleared for the full G envelope.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 22:47
by garrya
If that pedal turn is a yaw or nose pointing then why does it get limited by G limit ? :?

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 22:59
by steve2267
garrya wrote:If that pedal turn is a yaw or nose pointing then why does it get limited by G limit ? :?


I don't understand your question.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 23:03
by garrya
steve2267 wrote:
I don't understand your question.

Iam talking about this
“Even pre-IOC,[26] this jet has exceeded pilot expectations for dissimilar combat. (It is) G-limited now, but even with that, the pedal turns[27] are incredible and deliver a constant 28 degrees/second. When they open up the CLAW, and remove the (7) G-restrictions, this jet will be eye watering.”


According to your explanation then this is a yaw at high AoA correct ?
Image

I just dont see why G limit would really affect yaw rate at high AoA

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 19 Nov 2016, 23:17
by steve2267
I am not sure I can answer your question. It may require an actual F-35 driver or an engineer knowledgeable of the current state of the F-35 test program.

Also, what I described earlier is what I would call (educated) conjecture. I don't know if what I was describing is accurate or not. I am waiting for others to comment on what I posted.

That being said, I did not read the comments from the pilot you quoted as meaning that a currently imposed artificial g-limit (of 7g) is limiting yaw rate. The way I read those comments were gee... we're not allowed 9g just yet... but even with just a 7g limit we've got this fantastic maneuver that we can do instead -- a pedal turn -- that gives us 28°/sec sustained turn rate. Just wait until we can also pull 9g... the performance will be out of this world!.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 00:23
by smsgtmac
garrya wrote:
“Even pre-IOC,[26] this jet has exceeded pilot expectations for dissimilar combat. (It is) G-limited now, but even with that, the pedal turns[27] are incredible and deliver a constant 28 degrees/second. When they open up the CLAW, and remove the (7) G-restrictions, this jet will be eye watering.”



Steve, given a language problem appears to be at the root of the question, I think your very correct and complete answer may be lost on the target audience. Still, good answer. :thumb:

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 00:37
by steve2267
smsgtmac wrote:
Steve, given a language problem appears to be at the root of the question, I think your very correct and complete answer may be lost on the target audience. Still, good answer. :thumb:


Hey sgtmac, thx for the compliment. Any thoughts as to my earlier comments concerning possible relationship between pedal turns and a herbie (i.e. Herbst maneuver / J-turn)?

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 01:10
by spazsinbad
'steve2267' have you read this CODE ONE article? It is on pp 95-97 of 137 page PDF earlier & it is more easily read here:
Semper Lightning: F-35 Flight Control System
09 Dec 2015 Dan “Dog” Canin [LM F-35 Test Pilot Pax River]

"...Generally, the F-35 tries to keep sideslip near zero, but in some cases it intentionally creates adverse or proverse yaw as necessary to control roll and yaw rates. We’ll talk about the use of pedals at high AOA in a later article [never appeared], but, for general flying around, the best coordination we’ll get is with our feet on the floor [older hand flown miljets flown this way - in my era at least - 1960s-70s]....

...But Wait, There’s More!
FBW does more than just stabilize the airplane and clean up its response. It determines the very nature of the response itself. That response can be programmed to be whatever we want, as a function of the airplane’s configuration, speed, or whether it’s in the air or on the ground. For example, if we make a lateral stick input in CTOL mode, we get a roll rate. But in jetborne mode, we get a bank angle. At high speed, a pitch stick input commands a normal acceleration (“g”); at low speed with the gear up it commands a pitch rate; at low speed with the gear down, it commands an AOA; and in the hover, it commands a rate of climb or descent....

...Protecting Us From Ourselves
The control limiters in the F-35 – love them or hate them – are there to help. They not only make the airplane safer, but also more effective, by allowing us to fly aggressively without worrying about breaking something or losing control.

But flying the F-35 is not completely carefree. The control engineers had to give us some rope in a few places, since doing otherwise would have compromised capability and possibly even safety. So it’s important for us to understand what’s protected and what isn’t....

...Rolling and yawing – so-called “asymmetric maneuvering” (maneuvering using lateral stick or pedal inputs) – is another story. If we don’t pull more than 80 percent of the positive NzW limit or push to less than negative 1g, we can roll and yaw to our heart’s content. But if we push or pull more than that, we have to abide by a pilot-observed limit of 25 degree/second. (Stick your hand out in front of you and roll it through 90 degrees while counting to three potatoes. Yup, it’s slow.) I know what you’re thinking: “How do I know when I’m more than 0.8NzW?” You don’t – unless you’re good at mentally dividing the basic flight design gross weight (BFDGW) by your current gross weight and multiplying it by 0.8 times the basic g-limit for the airplane. (If you can do that, continuously, you’re probably in the wrong line of work.) And, “Why 25 deg/sec?” Because that’s the loads folks’ definition of “zero”: if you’re rolling less than 25 deg/sec, they consider that not rolling, so symmetric limits apply.

But, mostly, you’re thinking: “What’s with the pilot-observed limit? Why couldn’t the control engineers just protect us with CLAW?” The reason is that the analysis and the design work to handle every asymmetric input, under every flight condition and loading, would be prohibitive. And if they put the 25 deg/sec limit into CLAW, it would be tactically restrictive and possibly unsafe. So they picked the middle ground of telling us not to roll too much while we’re on the g-limiter.

So what happens if we make a big roll input at 0.9 NzW? First of all, the CLAW folks haven’t completely abandoned us: As g increases, the roll rate is reduced, and, if we’re commanding more than 50 deg/sec, the airplane unloads to get us back within the 0.8NzW limit. But there’s no guarantee that the unload will be quick enough to prevent an overload.

Does that mean we can break the airplane by pulling and rolling? Not really. The pilot-observed limits were decreed to make sure the airframe delivers its contractually specified life. If we exceed them, the wings won’t fall off, but we might reduce some of that life. The bottom line: If you’re on the g-limiter and want to roll, back off a little, then roll. This will not only keep you within the rules, it will give you a better roll rate in the bargain. If you can’t back off – because, say, you’re trying not to hit the ground, or trying not to get shot (and I don’t mean by your buddy during BFM) – then do what you need to do! The worst thing that will happen is that you’ll trip an OVER G advisory or an overload HRC,[5] and have to explain your heroic act to the maintenance officer when you return. Presumably, the maneuver will be worth the airframe life you expend....

...The F-35 is an inherently unstable airplane, required to handle a wide range of CG. Its control surfaces are sized to meet the requirements of both maneuverability and low observability. As a result, the combinations of body rates, AOAs, CGs, Machs, and weapon bay door positions that define the controllable envelope of the F-35 are extremely complex – and the boundaries of that envelope are reflected, with all that complexity, in CLAW. If the control engineers opened up the limiters and gave us, instead, “rules of thumb” to maintain control – ones that we had a fighting chance of remembering – the rules would most likely be so restrictive that we’d give up more than we gained. Could we evolve to that in the future? Sure, if we decide it’s a positive trade. As the control engineers hate to hear us say, “It’s only software.”...

...The second article will address how FBW works in the F-35, and why it was designed that way." [NOT SEEN SO FAR!]

"[5] An OVER G advisory will trip if you exceed the book symmetric or asymmetric maneuvering limits by more than 0.5g. For the purposes of this ICAW, the airplane defines as “asymmetric” any roll rate over 50 deg/sec, so there’s a 25 deg/sec buffer there as well. So if you stick to the flight manual roll rate limit, you should never see this ICAW. What you might trip, though, is an “overload” HRC, which has a much more sophisticated algorithm behind it and will only trip when you’ve exceeded an actual limit on some component of the structure. CLAW should in all cases prevent actual overload to failure, but during rolling maneuvers it may allow one of these indications to trip, requiring a maintenance inspection."


Source: http://www.codeonemagazine.com/article.html?item_id=187

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 02:34
by steve2267
spazsinbad wrote:'steve2267' have you read this CODE ONE article? It is on pp 95-97 of 137 page PDF earlier & it is more easily read here:


No, i had not read that before! Thanks for posting.

I'm a slow reader. When i saw 137 pages, part of me died. But its great material... But gonna take me a little while to chew through it.

Sounds like that fellows question has some merit, but as for me, your post clarified everything.

I'm sure someone @ LM or on the JSF team has thought about this... But a simple bar graph doofer (like a speed or AOA tape) displaying 0.8 * NzW in real time woul provide instantaneous feedback to the pilot as to whether full roll/yaw is available or if he needs to relax a little G first.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 03:24
by spazsinbad
An F-35 pilot will be looking through the vHUD (virtual HUD) via the HMDS III (light) - not at anything anywhere else during ACM. What is on the vHUD? Go here (I need to find it now).... Search F-35 forum with vHUD THIS thread surprisingly has a lot of vHUD info - go there and search the thread (top left) for vHUD

Helmet-mounted displays viewtopic.php?f=62&t=16223




Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 03:48
by steve2267
spazsinbad wrote:An F-35 pilot will be looking through the vHUD (virtual HUD) via the HMDS III (light) - not at anything anywhere else during ACM. What is on the vHUD? Go here (I need to find it now).... Search F-35 forum with vHUD THIS thread surprisingly has a lot of vHUD info - go there and search the thread (top left) for vHUD

Helmet-mounted displays viewtopic.php?f=62&t=16223



MORE to read! It never ends! Thanks for the link spazs. I'll add it to the reading list.

The doofer doesn't need to be on the instrument flat panel. You could have a small vertical tape, or upside down right triangle... or even a caret that slides up and down. Put it alongside the GS / M / g info on the left. A quick glance would tell the pilot if he can still command full roll / yaw. I dunno. Just a thought so he doesn't have to try to calculate Gross Weight / Combat Weight * 0.8 * g-limit or whatever that formula was. Have the 'puters do the 'rithmetic and put up a real simple real time readout on the vHUD. Or not. Or make it a pilot selectable feature if they want to see it or not.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 04:07
by spazsinbad
Heheh You think it is a good idea. IF the vHUD/HUD/PCD designers (LM 'head' designer Mike Skaff former F-16 pilot with input from lots of pilots) wanted that info it would be available. Dan Canin implies it is all taken care of by whatever - no problem. The F-35 is designed to take out the flying headwork so that the pilot concentrates on other things. They say so.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 04:53
by steve2267
spazsinbad wrote:Heheh You think it is a good idea. IF the vHUD/HUD/PCD designers (LM 'head' designer Mike Skaff former F-16 pilot with input from lots of pilots) wanted that info it would be available. Dan Canin implies it is all taken care of by whatever - no problem. The F-35 is designed to take out the flying headwork so that the pilot concentrates on other things. They say so.


Ok, so I'm out-voted. Wait, no... It's NOT ok -- you're not MY hud designer! That vHUD is sexist! Oops... Sorry... Wrong election / thread. :mrgreen:

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 06:06
by spazsinbad
I left out PVI - Mike Skaff is the head honcho of this - Pilot :mrgreen: Vehickle :doh: Interface design. Search forum on SKAFF

:roll: Here's a relevant CLASSIC thread! :drool: viewtopic.php?f=22&t=29126&p=318873&hilit=skaff#p318873
with: viewtopic.php?f=22&t=29126&p=318871&hilit=skaff#p318871 & viewtopic.php?f=62&t=27582&p=296048&hilit=skaff#p296048 & viewtopic.php?f=22&t=27186&p=294040&hilit=skaff#p294040


Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 06:25
by johnwill
steve2267 wrote:I am not sure I can answer your question. It may require an actual F-35 driver or an engineer knowledgeable of the current state of the F-35 test program.

Also, what I described earlier is what I would call (educated) conjecture. I don't know if what I was describing is accurate or not. I am waiting for others to comment on what I posted.

That being said, I did not read the comments from the pilot you quoted as meaning that a currently imposed artificial g-limit (of 7g) is limiting yaw rate. The way I read those comments were gee... we're not allowed 9g just yet... but even with just a 7g limit we've got this fantastic maneuver that we can do instead -- a pedal turn -- that gives us 28°/sec sustained turn rate. Just wait until we can also pull 9g... the performance will be out of this world!.


The flight conditions for using pedal turns are at low airspeeds, high AoA, think 200 kcas and 30 or 40 degrees. That also means you cannot attain much in the way of g, perhaps 2 or 3. So it really does not matter what the g limiter is (7,9, whatever), you are not going to be limited by it. Therefore, don't expect any more capability at these conditions when the limiter is raised to 9. If the later software opens up the roll and yaw authority, then you can expect more maneuverability. Only when airspeed is high enough to exceed 7g will the increased g limit be of benefit.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 20 Nov 2016, 14:35
by quicksilver
Pedal turns happen at very low speeds (<200 KIAS) and (as jw suggests) high alpha. Aircraft is rotating around the flight path vector. Typically occurs tactically coming out of slow speed nose high reversals going back down hill and is fairly transient. If not (e.g. near vertical nose-low canopy to canopy roller) eventually one has to transition out of the maneuver (due to an approaching low speed deck as the jet(s) are coming out of the sky like a ton of ___) and you end up in a lufberry.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 21 Nov 2016, 04:13
by gta4
steve2267 wrote:I could see where that 28°/sec comes from and really makes the F-35 dangerous close in. I wouldn't want to get slow and stay there, but if you've got the smash to get your speed back... yeah, they might be re-writing the book on knife fighting in a phone book.

Yes F-35 has the power to quickly recover airspeed. It could out-accelerate Su-27/35 with a significant margin in subsonic region. Check the data here:
viewtopic.php?f=55&t=52510

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 12 Jan 2019, 18:22
by garrya
This is the most impressive pedal turn i have ever seen:
https://facebook.com/story.php?story_fb ... 7895604049

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 12 Jan 2019, 21:17
by spazsinbad
The magic of flight from same 'garrya' source as above: https://www.facebook.com/TXAFTERBURNER/ ... 755539210/

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 13 Jan 2019, 03:19
by mr.gibbys
garrya wrote:This is the most impressive pedal turn i have ever seen:
https://facebook.com/story.php?story_fb ... 7895604049


Some of the video also shows pitch pointing, an attribute related to DFCS, which essentially makes an aircraft super maneuverable.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 13 Jan 2019, 07:05
by popcorn
Hopefully one day they record the demo from a camera plane.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 13 Jan 2019, 23:01
by spazsinbad
Better quality but same video as the one attached above but from THE DOJO account by all accounts - THE COUNT!

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 02:42
by gta4

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 02:45
by knowan
garrya wrote:This is the most impressive pedal turn i have ever seen:
https://facebook.com/story.php?story_fb ... 7895604049


Reading those facebook comments made me lose a few IQ points.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 15:17
by mixelflick
I dunno what this says, but a cat we're babysitting watched the Luke pedal turn and went berserk pawing at it LOL. It's incredibly impressive, especially the way the F-35 does NOT turn into a falling leaf (like many of the Russian birds). The way it sticks it without losing altitude is impressive.

Would love to know how much fuel she's carrying, and whether or not this is possible with more than 60% internal fuel and a 5,000lbs weapons load?

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 15:30
by spazsinbad
Cats? Petal Turds? Full internal fuel/weapons no limits Cool For Cats https://www.youtube.com/watch?v=uJ2cEc_TCH8


Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 16:22
by quicksilver
mixelflick wrote:I dunno what this says, but a cat we're babysitting watched the Luke pedal turn and went berserk pawing at it LOL. It's incredibly impressive, especially the way the F-35 does NOT turn into a falling leaf (like many of the Russian birds). The way it sticks it without losing altitude is impressive.

Would love to know how much fuel she's carrying, and whether or not this is possible with more than 60% internal fuel and a 5,000lbs weapons load?


I must be watching a different video.

That jet is coming out of the sky very rapidly; for a few seconds it happens to be falling faster than it is going forward, and the only apparent motion to the viewer is from the bottom of the vertical cylinder that the jet is coming down within. If it were not coming down (“...without losing altitude...”)it would have been hovering, which it was not.

Measure the apparent wingspan at the beginning vs where you start to see fwd motion again.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 17:21
by garrya
quicksilver wrote:
I must be watching a different video.

That jet is coming out of the sky very rapidly; for a few seconds it happens to be falling faster than it is going forward, and the only apparent motion to the viewer is from the bottom of the vertical cylinder that the jet is coming down within. If it were not coming down (“...without losing altitude...”)it would have been hovering, which it was not.

Measure the apparent wingspan at the beginning vs where you start to see fwd motion again.

I think my eye is deceiving me too, but for some strange reason the jet seem to maintain its altitude or falling very slowly between 0:27-0:29 in the video

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 17:35
by lbk000
It's perspective coupled with a lack of visual references.

Image
Remember the [in]famous "Flanker tumble" from 2017? Everyone crapped their pants over what looked like the aircraft tumbling around in place, but that was because the path of travel was directly into the camera. When viewed from a different perspective it was much less impressive looking.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 17:55
by sprstdlyscottsmn
garrya wrote:
quicksilver wrote:
I must be watching a different video.

That jet is coming out of the sky very rapidly; for a few seconds it happens to be falling faster than it is going forward, and the only apparent motion to the viewer is from the bottom of the vertical cylinder that the jet is coming down within. If it were not coming down (“...without losing altitude...”)it would have been hovering, which it was not.

Measure the apparent wingspan at the beginning vs where you start to see fwd motion again.

I think my eye is deceiving me too, but for some strange reason the jet seem to maintain its altitude or falling very slowly between 0:27-0:29 in the video

The velocity Vector is pointing at the camera then

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 18:09
by quicksilver
sprstdlyscottsmn wrote:
garrya wrote:
quicksilver wrote:
I must be watching a different video.

That jet is coming out of the sky very rapidly; for a few seconds it happens to be falling faster than it is going forward, and the only apparent motion to the viewer is from the bottom of the vertical cylinder that the jet is coming down within. If it were not coming down (“...without losing altitude...”)it would have been hovering, which it was not.

Measure the apparent wingspan at the beginning vs where you start to see fwd motion again.

I think my eye is deceiving me too, but for some strange reason the jet seem to maintain its altitude or falling very slowly between 0:27-0:29 in the video

The velocity Vector is pointing at the camera then


Shack

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 14 Jan 2019, 18:33
by lbk000
On the topic of optical trickery, this is also what makes the F-35's powerslide turn maneuver look so showy. Wonder why it always climbs away from the audience? Aligning the velocity vector with the audience's sightline minimizes the apparent radius of the turn.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 15 Jan 2019, 00:26
by charlielima223
[quote="lbk000"Wonder why it always climbs away from the audience? Aligning the velocity vector with the audience's sightline minimizes the apparent radius of the turn.[/quote]

Its more for public safety rather than visual trickery

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 15 Jan 2019, 02:29
by knowan
Most impressive thing I find with the video is how the F-35 appears to have full control throughout the entire display; I can't say the same for Flankers and Migs doing similar moves.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 15 Jan 2019, 04:13
by sprstdlyscottsmn
This ^^. A thousand times this. The F-22 and F-35 displays look like the pilot is commanding everything. The Su-xx displays look like the pilot gives a large input, hangs on for dear life while Issac Newton drives for a bit, and then recovers.

Re: What is the pedal turn that generates a constant 28deg/s

Unread postPosted: 15 Jan 2019, 09:18
by hornetfinn
Like Jon Beesley said ten years ago about Sukhoi air show stunts that they are ballistic maneuvers with rather little control over what happens during the maneuver. He also described perfectly how F-22 and F-35 maneuvers during those same maneuvers.



Not the first time this video is shown here, but in this context it's spot on.