Agile F-35 High Wing Loading

[spazsinbad]

Thanks 'popcorn' - worth quoting what the unwashed can only see... Is this an AprilFoolManeuver?

F-35 Tested Against F-16 In Basic Fighter Maneuvers
02 Apr 2015 Guy Norris and Amy Butler | Aviation Week & Space Technology

"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 ..."

Source: http://aviationweek.com/defense/f-35-te ... -maneuvers

[KamenRiderBlade]

:mrgreen: Thanks 'popcorn' - worth quoting what the unwashed can only see... :devil: Is this an AprilFoolManeuver? :doh:

F-35 Tested Against F-16 In Basic Fighter Maneuvers
02 Apr 2015 Guy Norris and Amy Butler | Aviation Week & Space Technology

"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 ..."

Source: http://aviationweek.com/defense/f-35-te ... -maneuvers

Blocked by Aviation Week paywall.

[mrigdon]

I read a long time ago dropping a fuel tank was the equivalent of jettisoning a brand new BMW.

Pretty much. I found an article pricing tanks for the Gripen. http://www.defense-aerospace.com/articles-view/release/3/67610/ruag-wins-gripen-drop-tank-contract-(mar-27).html

So maybe not quite $100,000 a tank, but getting there.

[bring_it_on]

:mrgreen: Thanks 'popcorn' - worth quoting what the unwashed can only see... Is this an AprilFoolManeuver?

F-35 Tested Against F-16 In Basic Fighter Maneuvers
02 Apr 2015 Guy Norris and Amy Butler | Aviation Week & Space Technology

"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 ..."

Source: http://aviationweek.com/defense/f-35-te ... -maneuvers

Blocked by Aviation Week paywall.

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.”

[smsgtmac]

In the back of everyone's minds is, well of course, why would an F-16 haul EFTs, and bombs if it needs agility?
In the event of an emergency, any F-16 pilot would most certainly drop EFTs and A/G ordnance to get as much of a performance boost as possible[/b].

The F-16 fuel pylons are not jettisonable however, so about 25% of the pre-jettison drag count (assuming 2 fuel pylons and no adjacent stores) would remain. I've never seen/heard of an F-16 wing weapon pylon that was jettisonable (not that my limited experience with F-16 pylons 'signifies' anything) and their drag count adds up quick.

Want to know how the F-16 Block 50/52 compares to the F-35 KPP configuration? Look no further!

The 4000+ lb gorilla in the room is that the F-35 KPP weight includes giant JDAMS that could also be jettisoned if desired.

I'm 'Done' with the Block 50 comparisons. Almost done taking a stab at a Block 60/F-35A KPP parametric excursion in between crises and work.

[popcorn]

AvWeek does a good job when they stick to the facts.

[spazsinbad]

Thanks again 'BrungItBack' I like these last sentences (with most of the rest up there also): [& I agree with 'poppy']

"...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.”

It seems to me that the BMW drop tanks are made from whoknewnubium to be that expensive. Meanwhile back in the real world now some 45 years ago (my how drop tanks fly - not) here is the mentioned VC-724 Squadron Line Book page (elements re-arranged - we were not artistes - just B/S artists). I have told the story I think also that for the first few years the small 150 gal / 1,000 lb fuel drop tank was not available due Vietnam USN requirement. After the war was over when HMAS Melbourne was at Subic Bay a USN good guy gave permission for the VF-805 maintainers to grab a truck - go to a warehouse and take back as many small drop tanks they could manage (these would have to be stowed onboard). Generic drop tanks are certainly not expensive - but exactly what they cost I have no idea.

In an ordinary world I would never pose as seen (on the drop tank) however being ordered I had no choice. The drop tank front is severely dented along front visible side, with it resting on the damage adjacent to the floor. My instructor is in the toilet with the 2.75in rocket pod. I did not make the line book page. One large page element is missing from this cut and paste job however I cannot remember what it might be.

[johnwill]

Hey Johnwill, Im pretty sure I heard somewhere here that you worked on the Jap F-2 or atleast the F-16 Agile falcon program which was the basis for the F-2.

What can you say about it and how would it compare against the F-35?

A request - since I come from a day when "Jap" was a very negative expression, worse than the "N" word, it really irritates me to hear people use it today. I suspect you did not mean anything bad by using it. I lived and worked in Japan for a year and a half on the F-2 program, and the Japanese people of today are the finest group of people I have ever known. So please use "Japanese" when referring to them.

I can say a lot about the F-2, but I'd like to know what you are interested so I won't waste my time on things you don't care about.

All I know about the F-35 is what I read from many sources, some of which may be believed. So comparing it to the F-2 is difficult at best. The F-2 is like a slightly overgrown F-16, so if you read the F-16 / F-35 comparisons, you won't be far off. Since the F-2 is a little heavier and draggier than the F-16, yet uses a similar engine, it's performance lags the F-16 a little. For its mission, anti-shipping, it's just fine.

[spazsinbad]

Good article about 'drop tank developments' over the years (already mentioned elsewhere on this forum): and I'll guess if these people below make a 'carrier survivable external tank for the F-35C' then same tank will fit the other variants.

Carrier-capable, all-composite external fuel tank Legacy product positions builder for a shot at an F-35 contract.
02 May 2011 Michael R. LeGault

"...Rashilla says GDATP’s next major design/manufacturing opportunity for an all-composite external fuel tank is likely to be the F-35 Lightning II. He expects an external tank will be built for the new jet at some point but reports that funding has yet to be approved. “The survivability requirements for the tank used in the carrier variant of the F-35 will be essentially the same,” Rashilla says. “We hope to be able to apply the lessons we learned on our F/A-18 tank design to that project.”"

Graphic: http://d2n4wb9orp1vta.cloudfront.net/re ... rawing.jpg

Source: http://www.compositesworld.com/articles ... uel-tank(2)

[mk82]

" 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.”

I am getting a strong vibe that the F35 is pretty maneuverable at least vs a F16...with lots of potential performance left in the bag. Time to shove lots of crow down the throats of mouth breathers and basement dwellers who keeps repeating the nonsense that the F35 is not maneuverable. 110 degrees AOA and recovering from that!! I would like to see even a F16 do that! Can't wait to see what a block 3F F35 can do at airshows.

Looks like the only significant effect of those F35 transonic roll offs (TRO)s is the wing hitting ELP and co straight in the face!!

[johnwill]

smsgtmac said

"The F-16 fuel pylons are not jettisonable however, so about 25% of the pre-jettison drag count (assuming 2 fuel pylons and no adjacent stores) would remain. I've never seen/heard of an F-16 wing weapon pylon that was jettisonable (not that my limited experience with F-16 pylons 'signifies' anything) and their drag count adds up quick. "

Not true. The 370 gallon fuel pylons are bolted to the tanks and must be ejected with the tanks. The ejection mechanism is in the upper part of the pylon and pushes against a bracket bolted to the lower surface of the wing. There is a 600 gallon tank used by a few air forces (Israeli among them) and it uses a standard weapon pylon (with added fuel plumbing) and MAU-12 ejector rack (or more modern equivalent). In that case you would be correct, the fuel pylon is bolted to the wing and not ejected.

[smsgtmac]

smsgtmac said

"The F-16 fuel pylons are not jettisonable however, so about 25% of the pre-jettison drag count (assuming 2 fuel pylons and no adjacent stores) would remain. I've never seen/heard of an F-16 wing weapon pylon that was jettisonable (not that my limited experience with F-16 pylons 'signifies' anything) and their drag count adds up quick. "

Not true. The 370 gallon fuel pylons are bolted to the tanks and must be ejected with the tanks. The ejection mechanism is in the upper part of the pylon and pushes against a bracket bolted to the lower surface of the wing. There is a 600 gallon tank used by a few air forces (Israeli among them) and it uses a standard weapon pylon (with added fuel plumbing) and MAU-12 ejector rack (or more modern equivalent). In that case you would be correct, the fuel pylon is bolted to the wing and not ejected.

You're right.
I was working off my exported spreadsheet data. Going back to the source:

NJETT-Fuel-Pylon.jpg (75.59 KiB) Viewed 18718 times

[zero-one]

A request - since I come from a day when "Jap" was a very negative expression, worse than the "N" word, it really irritates me to hear people use it today. I suspect you did not mean anything bad by using it. I lived and worked in Japan for a year and a half on the F-2 program, and the Japanese people of today are the finest group of people I have ever known. So please use "Japanese" when referring to them.

I can say a lot about the F-2, but I'd like to know what you are interested so I won't waste my time on things you don't care about.

All I know about the F-35 is what I read from many sources, some of which may be believed. So comparing it to the F-2 is difficult at best. The F-2 is like a slightly overgrown F-16, so if you read the F-16 / F-35 comparisons, you won't be far off. Since the F-2 is a little heavier and draggier than the F-16, yet uses a similar engine, it's performance lags the F-16 a little. For its mission, anti-shipping, it's just fine.

I'm very sorry John, I've worked with some Japanese people as well, and you're right, they are a fine bunch, very humble and polite. I think we should start redeeming the "Jap" term and stop affiliating it with the negative notations of WWII.

but yeah, I'll use Japanese from now on.

Anyway, since the F-2 is an overgrown F-16, I was thinking so is the F-35, although it does have more wing and a bigger engine.

So what airplane more closely matches the F-35's performance? is it the F-16C block 52 or the F-2? or none?

[zero-one]

From the AV week article,

WOW, 110 degress AOA?
I guess it's safe to say that the airplane is at least a match against the F/A-18E in slow speed high Alpha maneuvers.

however, I'd like to know more on how she handles high G?

can she out maneuver the Viper?

after all this is a flight science test against the Viper,

how did she do?

[mor10]

From the AV week article,

WOW, 110 degress AOA?

What I wonder is what control surface deflection could possible make it come back from 110 degrees?