Block 50 F-16XL

[Viper1031]

I know there will be a lot of kickback on  this, and a whole lot of 'it's not gonna happen' but it's a wishlist right? So, I submit, Block 50 F-16XL, I understand there would be a lot of work involved, but there would also be a lot of work already done: Cockpit and systems already modeled, it of course would require a revamp of the model, and flight model, but there are quite a few fans of the XL, and this would be a way to bring it to life in DCS.

[F-2]

15 hours ago, Viper1031 said:

I know there will be a lot of kickback on  this, and a whole lot of 'it's not gonna happen' but it's a wishlist right? So, I submit, Block 50 F-16XL, I understand there would be a lot of work involved, but there would also be a lot of work already done: Cockpit and systems already modeled, it of course would require a revamp of the model, and flight model, but there are quite a few fans of the XL, and this would be a way to bring it to life in DCS.

If you really want an XL just play it strait and do the real thing. It was completed enough for DCS. The two prototypes had a strange mix of Block 30 and block 0 avonics, weapons could be fired and they had APG-68. You have three engines to choose from. 

[Viper1031]

On 10/4/2022 at 1:01 PM, F-2 said:

If you really want an XL just play it strait and do the real thing. It was completed enough for DCS. The two prototypes had a strange mix of Block 30 and block 0 avonics, weapons could be fired and they had APG-68. You have three engines to choose from. 

If I had the skills and a team to do it, then I'd get on top of it. 

[F-2]

13 minutes ago, Viper1031 said:

If I had the skills and a team to do it, then I'd get on top of it. 

You should look into the basics of modding and see if you like it. NASA has tons of data on the XL and you might be able to request more.

[AG-51_Razor]

It is a beautiful airplane! It would be a first day buy for me

[Viper1031]

14 hours ago, F-2 said:

You should look into the basics of modding and see if you like it. NASA has tons of data on the XL and you might be able to request more.

I'll give it a shot and see

[F-2]

6 minutes ago, Viper1031 said:

I'll give it a shot and see

 Here is how you create a EFM dcs. My advice play around a bit, use official Aerodynamic and engine data to see if you can make something and then use that to show people your serious. It seems Mod to 3rd party is becoming increasingly popular as a path to development.

[Viper1031]

51 minutes ago, F-2 said:

 Here is how you create a EFM dcs. My advice play around a bit, use official Aerodynamic and engine data to see if you can make something and then use that to show people your serious. It seems Mod to 3rd party is becoming increasingly popular as a path to development.

Thank you for that, I have nothing but time these days, so, I'm gonna be checking this out for sure

[mkellytx]

The XL's were pieced together demonstrators, early model jets rebuilt with some C model avionics.  Both started with the analog FLCS, one later got the digital FLCS for NASA, but was a bit limited since they weren't sure if they'd overstress the airframe with the added control authority.  There's a NASA report that describes all this in detail on the technical server.

The nice thing about the XL's is that their aerodynamics are one of the best understood, measured and documented of any recent supersonic aircraft.  NASA collected a lot of data for HSCT that was later made public and is often used as the gold standard to verify CFD code for technical papers.  The bad news is that the P&FQ were never fully developed/completed as the two aircraft were never more than demonstrators.  The above mentioned NASA report discusses one of the pitch instabilities which led to very bad Cooper-Harper scores for gun tracking, since there was no development program, no root cause was determined and no corrective action taken. 

While the aero model is very well understood, there is never were any operationally accepted flight control laws that met acceptable P&FQ Mil Stds.

It's a great idea, Block 50 avionics would fit the time frame they would have been delivered, but the flight/handling qualities would be pure speculation as they were never completed in real life.

[Viper1031]

1 hour ago, mkellytx said:

The XL's were pieced together demonstrators, early model jets rebuilt with some C model avionics.  Both started with the analog FLCS, one later got the digital FLCS for NASA, but was a bit limited since they weren't sure if they'd overstress the airframe with the added control authority.  There's a NASA report that describes all this in detail on the technical server.

The nice thing about the XL's is that their aerodynamics are one of the best understood, measured and documented of any recent supersonic aircraft.  NASA collected a lot of data for HSCT that was later made public and is often used as the gold standard to verify CFD code for technical papers.  The bad news is that the P&FQ were never fully developed/completed as the two aircraft were never more than demonstrators.  The above mentioned NASA report discusses one of the pitch instabilities which led to very bad Cooper-Harper scores for gun tracking, since there was no development program, no root cause was determined and no corrective action taken. 

While the aero model is very well understood, there is never were any operationally accepted flight control laws that met acceptable P&FQ Mil Stds.

It's a great idea, Block 50 avionics would fit the time frame they would have been delivered, but the flight/handling qualities would be pure speculation as they were never completed in real life.

 

While very true, the pure speculation bit didn't stop a couple of someones from putting out an F-22, granted it isn't PFM and FF cockpit,  drag wouldn't be difficult to figure out, pitch, yaw, and roll are known, yes, it would be speculation on the thrust variable upon the FM for the XL, since if we're talking Block 50, it as a much better TTWR (Thrust to weight Ratio) than the block 30/32, but it wouldn't be THAT much speculation if the thrust numbers were used, the XL (clean of course) achieved supercruise by accident, we know the weapons it would use since it in fact DID compete against what would become the Strike Eagle, we know the weight, the fuel, etc, as long as it isn't over the top, it would be a nice addition I believe. (Not gonna lie, I'd love a Hawk Hunter F-16XL from the Wingman series, but it's just not realistic lol)

[mkellytx]

22 hours ago, Viper1031 said:

 

While very true, the pure speculation bit didn't stop a couple of someones from putting out an F-22, granted it isn't PFM and FF cockpit,  drag wouldn't be difficult to figure out, pitch, yaw, and roll are known, yes, it would be speculation on the thrust variable upon the FM for the XL, since if we're talking Block 50, it as a much better TTWR (Thrust to weight Ratio) than the block 30/32, but it wouldn't be THAT much speculation if the thrust numbers were used, the XL (clean of course) achieved supercruise by accident, we know the weapons it would use since it in fact DID compete against what would become the Strike Eagle, we know the weight, the fuel, etc, as long as it isn't over the top, it would be a nice addition I believe. (Not gonna lie, I'd love a Hawk Hunter F-16XL from the Wingman series, but it's just not realistic lol)

There's a lot to unpack here, so warning long post!

Any F-16 aficionado, especially those of the XL variety should download and read Elegance in Flight, Albert C. Piccirillo.   It's the official NASA history of the F-16XL, written by a retired AF O-6 pilot type.  The PDF is free and it's the best plain English history of the subject. Link below:

Elegance in Flight

The book answer most of the typical topics that arise in the the XL wish list threads, or at least why things can't be done.

The difference in type and nature of speculation with the F-22 example is that the F-22 is a finished product.  There are control laws written, new flight computers, new engines, a functioning weapons system, multitudes of changes aerodynamic and structural from the YF-22 demonstrators to the F-22.  The XL's are a slightly more refined demonstrators than the YF-22.  The point is there was major development work needed to make a functional weapons system, which would take money away from other priorities (ATF) so the AF chose not to spend the money, it made sense at the time, the Cold War was about to end, the extra capability wasn't worth the cost/threatened to encroach on the ATF's level of performance and the Med Hen/Block 40/50 was good enough.

Never seen TTWR, we always use T/W, been a aero engineer since the 90's, minor nit to pick.  What isn't minor is the difference between static and dynamic, and transient versus steady state.  Thrust, drag, weight, lift coefficients, drag polars all tend towards static equilibrium states, which is fine since most aircraft spend most of their time in such conditions, level flight, constant climb/descents, boring airliner stuff .  So the really good aero data set NASA captured was generally aimed for HSCT (High Speed Civil Transport), airliner stuff, static equilibrium stuff.  Still important, still needed, but not enough for a proper flight model.  Fighters are all about handling/flight qualities which are dynamic and transient in nature.  That stuff is a bit harder to come by, it requires knowledge of actuator properties, moments and products of inertia, aerodynamic derivatives (C dot coefficients).  It's a lot harder to measure and the folks who do it usually attend a test pilot school for a year to learn the basics.  I flew for 5 years at one of those locations (Edwards), did some projects in P&FQ and attended the Equations of Motion block for the school house, which involved deriving the full up 6 DOF EOM's from sum of forces and conservation of angular momentum and all of the fun transformation to go from body fixed coordinates systems to Earth inertial.

All that to say, the one program that did flight control law work was a one off demonstration that had some well documented deficiencies with indeterminate root cause.  That of course could be simulated, but the amount of complaints it would generate would kill the module.

Of course it would be really cool to get an XL from a alternate history Cold War didn't end/the KGB coup happened in 1987 instead of 1991 and succeeded...