The F-35 Thread

[mvsgas]

click on image to enlarge

[Winfield_Gold]

click on image to enlarge

 

Doug Masters pulled the same manoeuvre in a 172 :megalol:

[ФрогФут]

click on image to enlarge

Erhm... Do i really see vertical tail behind the stabs, which means that's negative g cobra?

[VincentLaw]

Erhm... Do i really see vertical tail behind the stabs, which means that's negative g cobra?

Yeah, it looks like an inverted, negative g, extreme angle of attack maneuver, though I think it would need to exceed 90 degrees to be considered a true Cobra. In the photo it looks somewhere around 70 or 80 degrees.

[NRG-Vampire]

that's negative g cobra?

 

yep, looks like - what is very dangerous to the pilot (can cause stroke)

[GGTharos]

It's not possible to tell what you're seeing in this image. There's no contrast on the aircraft itself and the positioning doesn't make anything clear. The entire shape is a little strange.

 

This one is more clear:

 

 

Erhm... Do i really see vertical tail behind the stabs, which means that's negative g cobra?

Edited March 22, 2015 by GGTharos

[mvsgas]

I just thought it was a cool image. Why you guys thinks is an "negative G" cobra? I thought it was just a picture of High AOA/departure testing. Look at 2:29 on this video.

 

 

[ФрогФут]

It's not possible to tell what you're seeing in this image. There's no contrast on the aircraft itself and the positioning doesn't make anything clear. The entire shape is a little strange.

You see shapes of stabs and vertical tails.;)

[GGTharos]

It looks like negative AoA test :)

[NineLine]

[Bucic]

I've just came to a realization that the F-35's fuselage-elevator transition is so streamlined I don't even know how the joint is designed! :huh: Do they use some kind of 'boot' on the gaps?

http://i0.wp.com/news.usni.org/wp-content/uploads/2014/06/f-35b_USMC.jpg

i0.wp.com/news.usni.org/wp-content/uploads/2014/06/f-35b_USMC.jpg

Edited April 8, 2015 by Bucic

[Pilotasso]

You mean rubbery sleeve?

[mvsgas]

I've just came to a realization that the F-35's fuselage-elevator transition is so streamlined I don't even know how the joint is designed! :huh: Do they use some kind of 'boot' on the gaps?

Not sure where are you referring to. Do you mean like the green areas on the picture you posted?

[Bucic]

You mean rubbery sleeve?

 

Not sure where are you referring to. Do you mean like the green areas on the picture you posted?

 

Yes and yes.

 

Boot, bellow, sleeve... Something to cover the gap that would normally appear even at moderate elevator deflections.

 

You can also see that for high elevator defl. (for nose down at least) the shape of the rear part of the fuselage and the entire root part of the elevator blends and clearly constitutes an intentional aerodynamic shape. Amazing!

Edited March 28, 2015 by Bucic

[Bucic]

click on image to enlarge

I know it may even be a glitch but I simply can't forget that 'aviaexpert'... What was that about F-35 losing to MiG-21 in a dogfight? :D And those RT blokes were all over it.

Edited March 28, 2015 by Bucic

[mvsgas]

Yes and yes.

 

Boot, bellow, sleeve... Something to cover the gap that would normally appear even at moderate elevator deflections.

 

You can also see that for high elevator defl. (for nose down at least) the shape of the rear part of the fuselage and the entire root part of the elevator blends and clearly constitutes an intentional aerodynamic shape. Amazing!

 

I never worked on a F-35, hell, never been close enough to see this panels. On other aircraft, areas that move and have panels like those are just metal. The panels are design to rub against each other. If you look at pictures of the F-16 wing, the Leading Edge Flap ( LEF) has panels like that. I assume and can only guess the F-35 has similar panels. Whether is made of meal or other composite, I have no idea.

[Bucic]

I never worked on a F-35, hell, never been close enough to see this panels. On other aircraft, areas that move and have panels like those are just metal. The panels are design to rub against each other. If you look at pictures of the F-16 wing, the Leading Edge Flap ( LEF) has panels like that. I assume and can only guess the F-35 has similar panels. Whether is made of meal or other composite, I have no idea.

I see. Do the joints on F-16 feature some exchangeable contact components or is it just skin on skin or other base structure?

 

Regarding F-35 my initial impression is that at least some surface transitions are impossible without some elastic intermediate components.

[mvsgas]

I see. Do the joints on F-16 feature some exchangeable contact components or is it just skin on skin or other base structure?

 

Regarding F-35 my initial impression is that at least some surface transitions are impossible without some elastic intermediate components.

 

Not all joints on the F-16. Only Flaperon, rudder and Leading Edge Flap (LEF). Not sure if I understand your question, the panels are called seals ( they have a panel number assigned to them, I can't remember what it is). One set of the panels is curved, so as the surface moves it still cover the area.

Edited March 31, 2015 by mvsgas

[Bucic]

Not all joints on the F-16. Only Flaperon, rudder and Leading Edge Flap (LEF). Not sure if I understand your question, the panels are called seals ( they have a panel number assigned to them, I can't remember what it is). One set of the panels is curved, so as the surface moves it still cover the area.

That would pretty much be it. Thank you! Sorry for derailing the topic a bit. I see myself staring at tens of carrier trial videos during the following months to uncover the mystery of the F-35 tail section kinematics ;)

[Basher54321]

The F-35 Joint Strike Fighter has been flown in air-to-air combat maneuvers against F-16s for the first time and, based on the results of these and earlier flight-envelope evaluations, test pilots say the aircraft can be cleared for greater agility as a growth option.

 

Although the F-35 is designed primarily for attack rather than air combat, U.S. Air Force and Lockheed Martin test pilots say the availability of potential margin for additional maneuverability is a testament to the aircraft’s recently proven overall handling qualities and basic flying performance. “The door is open to provide a little more maneuverability,” says Lockheed Martin F-35 site lead test pilot David “Doc” Nelson.

 

The operational maneuvers were flown by Nelson in AF-2, the primary Flight Sciences loads and flutter evaluation aircraft, and one of nine F-35s used by the Edwards AFB-based 412th Test Wing for developmental testing (DT). The F-35 Integrated Test Force at Edwards has six F-35As, two F-35Bs and a single F-35C dedicated to DT work, as well as a further set of aircraft allotted to the Joint Operational Test Team. Work is underway as part of efforts to clear the final system development and demonstration (SDD) maneuvering envelopes on the way to initial operational capability (IOC). The U.S. Marine Corps F-35B IOC is targeted for later this year, the Air Force’s F-35A in 2016, and the U.S. Navy’s F-35C in 2019.

 

“When we did the first dogfight in January, they said, ‘you have no limits,’” says Nelson. “It was loads monitoring, so they could tell if we ever broke something. It was a confidence builder for the rest of the fleet because there is no real difference structurally between AF-2 and the rest of the airplanes.” AF-2 was the first F-35 to be flown to 9g+ and -3g, and to roll at design-load factor. The aircraft, which was also the first Joint Strike Fighter to be intentionally flown in significant airframe buffet at all angles of attack, was calibrated for inflight loads measurements prior to ferrying to Edwards in 2010.

 

The operational maneuver tests were conducted to see “how it would look like against an F-16 in the airspace,” says Col. Rod “Trash” Cregier, F-35 program director. “It was an early look at any control laws that may need to be tweaked to enable it to fly better in future. You can definitely tweak it—that’s the option.”

 

“Pilots really like maneuverability, and the fact that the aircraft recovers so well from a departure allows us to say [to the designers of the flight control system laws], ‘you don’t have to clamp down so tight,’” says Nelson. Departure resistance was proven during high angle-of-attack (AOA) testing, which began in late 2012 with the aircraft pushing the nose to its production AOA limit of 50 deg. Subsequent AOA testing has pushed the aircraft beyond both the positive and negative maximum command limits, including intentionally putting the aircraft out of control in several configurations ranging from “clean” wings to tests with open weapons-bay doors. Testing eventually pushed the F-35 to a maximum of 110 deg. AOA.

 

An “aggressive and unique” approach has been taken to the high AOA, or “high alpha” testing, says Nelson. “Normally, test programs will inch up on max alpha, and on the F-22 it took us 3-4 months to get to max alpha. On this jet, we did it in four days. We put a spin chute on the back, which is normal for this sort of program, and then we put the airplane out of control and took our hands off the controls to see if it came back. We actually tweaked the flight control system with an onboard flight test aid to allow it to go out of control, because it wouldn’t by itself. Then we drove the center of gravity back and made it the worst-case configuration on the outside with weapons bay doors and put the aircraft in a spin.” The aircraft has been put into spins with yaw rates up to 60 deg./sec., equal to a complete turn every 6 sec. “That’s pretty good. But we paddled off the flight-test aid and it recovered instantly,” he says.

 

Pilots also tested the ability of the F-35 to recover from a deep-stall in which it was pushed beyond the maximum AoA command limit by activating a manual pitch limiter (MPL) override similar to the alpha limiter in the F-16. “It’s not something an operational pilot would do, but the angle of attack went back and, with the center of gravity way back aft, it would not pitch over, but it would pitch up. So it got stuck at 60 or 70 deg. alpha, and it was as happy as could be. There was no pitching moment to worry about, and as soon as I let go of the MPL, it would come out,” Nelson says.

 

Following consistent recoveries, the test team opted to remove the spin chute for the rest of the test program. “The airplane, with no spin chute, had demonstrated the ability to recover from the worst-case departure, so we felt very confident, and that has been proven over months of high alpha testing,” says Nelson. “It also satisfied those at the Joint Program Office who said spin chute on the back is not production-representative and produces aerodynamic qualities that are not right.” Although there are additional test points ahead where the spin chute is scheduled to be reattached for departure resistance with various weapons loads, the test team is considering running through the points without it.

 

With the full flight envelope now opened to an altitude of 50,000 ft., speeds of Mach 1.6/700 KCAS and loads of 9g, test pilots also say improvements to the flight control system have rendered the transonic roll-off (TRO) issue tactically irrelevant. Highlighted as a “program concern” in the Defense Department’s Director of Operational Test and Evaluation (DOT&E) 2014 report, initial flight tests showed that all three F-35 variants experienced some form of wing drop in high-speed turns associated with asymmetrical movements of shock waves. However, TRO “has evolved into a non-factor,” says Nelson, who likens the effect to a momentary “tug” on one shoulder harness. “You have to pull high-g to even find it.” The roll-off phenomena exhibits itself as “less than 10 deg./sec. for a fraction of a second. We have been looking for a task it affects and we can’t find one.”

 

http://aviationweek.com/defense/f-35-flies-against-f-16-basic-fighter-maneuvers

[mvsgas]

Click on image to enlarge

F-35A Bay Watch

 

Lockheed Martin test pilot Paul Hattendorf flies F-35A AF-1 with a load of GBU-12s during a test flight from Edwards AFB, California.

Photo by Matthew Short

 

Transonic Tests

 

USAF Lt. Col. Peter Vitt was at the controls for Flight 233 of F-35A AF-1 for some transonic tests with the weapon bay doors open on 16 August 2012. The flight originated from the F-35 Integrated Test Force at Edwards AFB, California.

Photo by Tom Reynolds

[Ktulu2]

Very small internal payload...Of course 2 GBUs will be enough for most missions, but you only have 2 AAM if you get some action.

[mvsgas]

Not that different when compared to other aircraft

http://media.dma.mil/2015/Mar/11/2001023374/-1/-1/0/150310-F-MG591-318.JPG

Night Refueling Over Iraq

 

A Royal Netherlands Air Force F-16 Fighting Falcon receives fuel from a U.S. Air Force KC-135 Stratotanker assigned to the 340th Expeditionary Air Refueling Squadron, Mar 10, 2015, over Iraq. The F-16 will strike Da'esh targets in support Operation Inherent Resolve.(U.S. Air Force Photo/ Staff Sgt. Perry Aston)

Edited April 3, 2015 by mvsgas

[Tirak]

Very small internal payload...Of course 2 GBUs will be enough for most missions, but you only have 2 AAM if you get some action.

 

Two 2000lb bombs and a pair of AMRAAMs internally. Swap them out for SDBs and you up that to 8 SDBs and two AMRAAMs. Set for all AA work in the not too distant future and you're looking at 6 AMRAAMs. Compare that with typical strike packages and against the F-117A, which could only carry 2 bombs, and I'd say they're getting quite a bit of mission flexibility without adding the external pylons just with that.

[GGTharos]

If you're hauling bombs you're not looking for action, period, end of story. You'll have A2A cover to handle that, and any AAMs you take with you are basically for 'self escort', ie push enemies out of the way and so you won't be completely defenseless.

 

It's NOT for 'Ok I dropped bombs let's do some A2A'. That's just gaming mentality.

 

Very small internal payload...Of course 2 GBUs will be enough for most missions, but you only have 2 AAM if you get some action.