Lockheed P-38 Lightning - Design Study

[Ivan]

Hello Allen,

You might also want to build new Coolant Radiators for your J Lightning.
I was trying to hint at that in my earlier response but could not see enough detail to confirm that it was still a F Radiator.
The F model had a much flatter Radiator with a much taller but narrower opening.
I believe the Radiator switched to the new shape with the H model but the Intercoolers didn't change until the J model.

The best example of a F Lightning is "Glacier Girl". I believe the contours are faithful though you never know with a complete new build which is really what that bird is.

The Red Bull Lightning (formerly White Lightning of Lefty Gardner) is kind of a weird mixture: It has the L model Radiator because it started off life as a L, but it has the earlier model Cowl without Intercoolers. Then again, it doesn't have Turbos any more so I suppose Intercoolers aren't really necessary.
An interesting thing is that the equipment failure that ended the last flight of "White Lightning" was a supercharger impeller explosion, so I guess even the regular mechanical supercharger is dangerous and not just the turbocharger.

Regards.
- Ivan.

[Ivan]

Hello Aleatorylamp,

I thought about the Line versus Solid issue when I first encountered the problem. I changed one side to be a Line while leaving the other as a Solid. It made no difference. When one worked, so did the other. When one failed, so did the other.

They obviously DID work at one point as my testing with only three Components showed. They even with with a lot more.... Up to the point where I added the Wheels.

They HAVE worked for me in the past sometimes and on other projects they did not. I never quite understood why and still do not. I believe that at a certain resource limit, they transform somehow and when I have no other projects in the works, I will go experiment a bit more. The transformation is mostly a mirror because the Right works better as a Left and vice versa, but it isn't an exact mirror because leaving them out entirely works (doesn't work?) even better.
Until I can reliably predict the effect, I won't use it on a project.

The Nose to Wing Templates actually DO work sometimes. I know because I have used them. That was the easiest way I found to prevent the Cowl and Nose on the Macchi C.205 Veltro from bleeding through the Wing Cannon. I don't use them often so I don't know if they fail sometimes.

There are actually a bunch more bugs that I have encountered in AF99 over the years, but I had not bothered to document them for later reference. It was enough just to find a workable solution around the problem.

I don't know if I would really call this thread a Tutorial. I am not really trying to teach anything. I am not showing how I do things. I only describe a little and show the result.
I figured "Design Study" was a better description because it is really about the shapes of the late model P-38 and my attempts at trying to represent them within the limitations of Aircraft Factory 99. Also, I don't know which will come first: Finishing the model or hitting a resource limitation. I know it will be VERY close either way.

I really wish I had the source to Aircraft Factory 99. I can see many ways to make it a much more powerful tool than it is now.

Regards.
- Ivan.

[aleatorylamp]

Hi Ivan,

Yes, Design Study rather than tutorial, or even AF99 testing bed!

OK, thanks - so lines make no difference, and the templates do work on simple models.
Too bad... Who wants simple models?

It´s clear that after a certain degree of complication, AF99 starts glitching. This "threshhold" varies - sometimes it happens when too many individual parts are being used and AF99 protests, asking for "more conventional building techniques", i.e. wanting more components and/or structures to simplify its own life... Oh? Then why does a simple box-structure use a higher % parts count than 6 individual parts for the same shape? There aren´t even any bulkheads! Another AF99 mystery.

Textures start messing up too, and I have had to write coordinates manually into the .afa building files - so it isn´t always the WinXP Spanish keyboard config that is the culprit, as I recently thought. The decimal point just disappears and is substituted by a decimal comma, ruining the texture spread.

Although I can´t programme any source code, I did contact Abacus once by e-mail AF99 quoting my user and access code to ask about this. They were very kind and attentive, and surprised that anyone still used AF99, but said nobody there knows anything about it anymore because the programmer, who was there at the time the author wrote AF99, had left.

So it looks like workable solutions around the bugs are our only resort. Maybe it just adds to the fun!

Cheers,
Stephan

[Ivan]

Hello Aleatorylamp,

I know the Nose to Wing Template worked for the Macchi Veltro and that is hardly a simple model.
It even held together after texturing which occasionally causes problems when the project is near its limit.

From what I can tell, there are some internal limits to Aircraft Factory 99 that are not obvious.
The absolute HARD limits of 30 Components and 1200 Parts is pretty obvious.
The "Suggestion" for 75 Parts (or whatever it is) for a Component is not a hard limit.
I have exceeded it without consequence as for the Blohm & Voss BV-141B.
I have Component failures but I believe the reason was different.

If you look at the SCASM source for one of the models, with a Component, each of the Vertices is listed first with their offsets and then the polygons refer to those Vertices.
The interesting thing is that the ordering of the vertices determines the facing of the Part (as you would expect) even though the ordering of the vertices is entirely irrelevant inside AF99.
Although two Components may have the same number of polygons, I believe if many of the vertices are shared, it uses fewer resources inside AF99. My belief is that the limit is more about the number of vertices in the Component than the actual Parts count.

Occasionally, there is a build failure even though the resource useage is still well off the limit.
You can see this with the FW 190A screenshots shown earlier.
I have hit the same problem when extending the wings on the A6M2 Reisen.

I hit a similar problem with the B-25C Mitchell at about 1180 Parts:
I originally built the Tail Skid as a Structure. I believe a Structure normally costs about two more Parts than the simple count of its faces would suggest.
The problem was that other polygons started disappearing as I added pieces. I cured the problem by changing the Tail Skid to a Component which slightly lowered the Parts count. As you know, Components are scarce which is why I try not to use them unless I have no choice.

From a programming standpoint, perhaps it is an Array that is dimensioned a bit small. Perhaps it is a matter something called Heap size that limits the amount of memory that can be allocated.


Hello Allen,

I looked over some photographs last night. Seems like the H Lightning had the newer engine of the J model but still had the older style Coolant Radiators.

- Ivan.

[Ivan]

My assembly techique for most AF99 projects starts at the Cockpit with a Pilot figure.
This is because the Cockpit has the most small pieces that all come together in nearly the same place.

With AF99, the concept of a "Viewing Plane" is implemented with a "Glue" Part to attach a new piece to an existing assembly.
Each Glue Part describes an infinitely wide geometric plane that is used to determine what is in the Foreground and what is in the Background for display priority. Incorrectly determining display priority (Foreground / Background) is the cause of bleeds that are so common in CFS aeroplanes.

I have used the same pilot figure for the last several years.
In general, all that is needed to place him in a new aeroplane is to move all the Parts Longitudinally and Vertically and then extend or shorten the lower edges of the shoulder Parts to match the new Cockpit Floor.
Because most Pilots for my projects are at the aircraft centerline, there is no need for a Lateral shift.
To do this, I use a program called CMoveIt (Component Move It) which takes a set of offsets and relocates all the Parts within a Component.

The first screenshot shows the two Components required for this figure. Together, they cost two Components and about 65 Parts.

To locate the Pilot, I creaed a template from the Pilot's Components and use that to judge the correct location as can be seen in the second screenshot.

From photographs, the Pilot appears to sit with his head very close to the top of the Canopy with his eyes just above the window section that can be lowered. The longitudinal location is very near the peak of the Canopy.
My location by eyeball needs to be confirmed by a look at the pilot's seat location within the cockpit.

The Pilot in the P-38 sits very high in the cockpit. The edge comes down nearly to his waist.
In this case, this caused a little concern because if the lower edge of the Pilot extended too far, it would no longer fit onto the texture file allocated for it.
The Top and Bottom limits for the Pilot Shoulder texture are 1.40 feet apart.
The Cockpit edge is 0.95 above the Aircraft CoG.
As can be seen from the screenshot, the highest part of the Pilot's Neck is 2.08 feet above the Aircraft CoG, so we are still within the limits for using the current texture.

- Ivan.

[Allen]

Can I just widen the F radiator? Making new ones would be quite a pain. Geting the new radiator texture to match the stock would just a pain....

[aleatorylamp]

Hello Ivan,

I´m so sorry! By no means did I want to imply that your Macchi Veltro is a simple model!
I meant the T6 Texan default AF99 aircraft which the AF99 help files refers to, implying only that my 4-engined models and the P38 in this thread were too complicated for effective use of these templates.

Your insight and conclusions as to the possible cause are certainly very interesting and illustrating, and your examples of how to work around them will help more than one builder!

Thanks!
Stephan

[Ivan]

Can I just widen the F radiator? Making new ones would be quite a pain. Geting the new radiator texture to match the stock would just a pain....

You be the judge. Most people won't know the difference.
Consider that CFS has been around for well over a decade and I don't believe there has ever been a good flight model for the P-38 Lightning. At least I have never found one.

The stock aeroplanes in all the Combat Flight Simulators up to Version 3 all have some shape problems somewhere. I am sure the radiator won't be the biggest issue of that aeroplane. I was just pointing it out because this thread was intended as an exploration of the features and shapes in the P-38J. I will also build an early model Radiator assembly at some point in this thread, so folks can do a comparison then if they haven't already done it with photographs from the Internet.

THIS Lightning will have some shape problems as well, but they are due mostly to the resource limitations of the tools and my build methods which are hardly economical.

- Ivan.

[Ivan]

Shifting the Pilot to match the profile was very easy.
Finding the offsets was just a matter of matching up identical points.

A few more Cockpit pieces had to be built.
The Radio is a simle rectangular Structure.
The Walls and Floors are simple Insignia Parts matched to the edges of the Nacelle.
The very prominent Armour Plate behind the Pilot was an eyeball approximation of an image from a technical drawing.
It is actually two Parts to avoid any concave edges. I have absolutely no concern for these two pieces bleeding through each other because they are supposed to be co-planar polygons.
The Canopy Frame had to be split into a Left and Right Component with some overlap at the top to avoid bleeds.

The last two screenshots show the current status with a close up of the Canopy area.
This area is now full of bleeds and I am starting to run short of resources to address those bleeds.
Note that there are still very large missing areas that MUST be completed for any reasonable model.

Resource Count is now 25 Components out of 30 allowed and 1003 Parts of 1200 allowed.

The missing areas have been saved for last because of my "Least Commitment" principle of building:

The Control Panel and front of the Cockpit could be built as a Component (easiest), a Structure (not as nice looking) or as a set of parts glued together which would look like a "Sharp" Component but is most likely to cause a AF99 Failure. The choice depends on what resources remained after building more essential things.

There are still 2 Structures required for the Supercharger Intakes below the trailing edge of each outer wing section. I have never seen any other CFS Lightnings with those pieces as anything other than textures, so if I left them off, folks probably would not notice.

There should be an additional Component added to each Wing Root to remove some of the bleeds betwen the Inner Wing and Fuselage. From close up, these bleeds are much more severe with the new Cockpit pieces added.

There should be an additional Component added to each Boom in the missing section in order to get the shapes right with few bleeds.

Another Aircraft Factory 99 "Bug" can be seen in the last two screenshots:
The "Body, Main" group colour is Light Gray.
The Radio is a Medium Blue Structure with "Both Bulkheads" selected.
From the screenshots, it appears that the Radio is Light Gray with only the Bulkheads as a darker colour.
This "Feature" can be used to advantage with Gun Barrels to make the Muzzle Back (Structure colour) while the tube is coloured a lighter shade to be determined by the group colour.

- Ivan.

[Ivan]

I was debating on whether or not this was even worth its own post.

Radiator Openings were added.
They turned out pretty much as expected with 6 actual Parts and 6 Glue Parts to locate them.

So now the count is 1015 Parts.

Behind the scenes, quite a lot was changed, but nothing that would result in any change in appearance other than some minor colour changes so that like-coloured pieces are not visually adjacent to each other and so that pieces do not have to be added as "Opposite" in AF99.

This is done rather easily with a program called CMirror (Component Mirror).

- Ivan.

[Allen]

You be the judge. Most people won't know the difference.
Consider that CFS has been around for well over a decade and I don't believe there has ever been a good flight model for the P-38 Lightning. At least I have never found one.

The stock aeroplanes in all the Combat Flight Simulators up to Version 3 all have some shape problems somewhere. I am sure the radiator won't be the biggest issue of that aeroplane. I was just pointing it out because this thread was intended as an exploration of the features and shapes in the P-38J. I will also build an early model Radiator assembly at some point in this thread, so folks can do a comparison then if they haven't already done it with photographs from the Internet.

THIS Lightning will have some shape problems as well, but they are due mostly to the resource limitations of the tools and my build methods which are hardly economical.

- Ivan.

I'm not doing any major change to the shape. Just some Q and D engine intakes and un-mirroring the aircraft textures. I did pull out the rads intakes some.

Attachment 16645

[Ivan]

I'm not doing any major change to the shape. Just some Q and D engine intakes and un-mirroring the aircraft textures. I did pull out the rads intakes some.

Looks like a pretty good solution tp me. M$ also mirrored the textures on CFS2? That is pretty silly.
I should start up my copy of CFS2 to see what the rest of the stock Lightning looks like. I have been a bit hesitant because I only have a 15 inch monitor on that machine right now. A monitor failed on another machine and mine had to give up its monitor.

CFS2 at least has directional propeller rotation which is needed on the Lightning but generally not represented on CFS1 versions.
THAT was a fun exercise with this project.

- Ivan.

[Ivan]

The remaining sections of the two Booms were added.

Parts Count is up to 1073 of 1200 allowed.
Components Count is 27 of 30 allowed.

This is getting too close to the limit because there are many pieces that still have not been created.
There are still no Landing Gear Struts or Doors.
The Flaps still need to be added.
I still want to add Supercharger Intakes.
The front of the Cockpit is still missing.

There are a few bleeds that require duplication of a piece or two and will expend more Parts.

The last three screenshots show a few of the bleeds that become obvious when more pieces are completed.
None of the bleeds is particularly difficult to remove IF there are enough remaining resources.
Since there are not many resources left, it will be a serious bit of juggling and compromises and probably some non-intuitive reconstructions.

- Ivan.

[Allen]

Looks like a pretty good solution tp me. M$ also mirrored the textures on CFS2? That is pretty silly.
I should start up my copy of CFS2 to see what the rest of the stock Lightning looks like. I have been a bit hesitant because I only have a 15 inch monitor on that machine right now. A monitor failed on another machine and mine had to give up its monitor.

CFS2 at least has directional propeller rotation which is needed on the Lightning but generally not represented on CFS1 versions.
THAT was a fun exercise with this project.

- Ivan.

Yup. All aircraft in CFS2 had mirrored textures. TheB24Guy did Overhuals of all of them but the F4U (D-Bolt had already did one or two) to un-mirrored them, basic VC and working gauges added to the AI models a long time ago.

I still use a 15 inch monitor (Gateway FPD 1530 that matches the Gateway 500x it is attached to. )

[Ivan]

Here was the attempt to connect the new Boom section to the existing Cowl Component.
I had been reluctant to do this because it would make the Cowl Component very long and harder to texture well.

Only one texture file (256 pixels wide) must be used to cover 16.52 feet (more likely oto be 16.64 feet) on the model which makes each pixel cover a 0.78 inch square. Such big pixels make it difficult to put in good detail on a paint scheme.
The Lightning is a very large aeroplane and this is one of the consequences of building a large aeroplane in Combat Flight Simulator.

This single Component now contails 88 Parts.
I had been reluctant to add the new Boom pieces to the Cowl Component because I know that although it will not necessarily cause a bleed in the Component, it will make the Turbocharger bleed through the upper rear side. Luckily, most of the bleed will be covered by the Radiators behind them.

Note also the contour corrections as compared to the Cowl image posted earlier.

[Ivan]

Combining the new Cowl into the project frees up two Components (which we are always short of) though it doesn't significantly change the parts count. (It actually removes two Glue Parts that are no longer necessary.)

The major AF99 Rebuild is rearranging all of the Tail pieces from the "Tail" group to the "Tail, Left" and "Tail, Right" groups. This makes them line up with the Inner Wing group without bleeds. The bleed of the Radiator in a centrail Tail group through the Cowl in the Inner Wing or Boom section in either group looked to be very difficult to fix because so many pieces come together at that area.

An unfortunate result is that there is now a bleed of the Nacelle in the Body, Main group through the now missing central Tail group.
The fix here is rather easy but will expend one of the two Components saved from rebuilding the Cowl.

The current state is shown in the last screenshot along with arrows showing the current bleeds I know of. The Red arrows show the severe bleeds and the Blue arrows show the relatively minor bleeds. So far everything looks fixable perhaps even with the resources remaining.

Current Parts Count is now 1090 of 1200 allowed
Current Components Count is now only 25 of 30 allowed though 3 will be expended shortly to resolve the major bleeds noted above.

- Ivan.

[Allen]

Makes me glad the only bleeds we have with CFS2 are weapons and props. Thankfully they are intermeten.

[Ivan]

Hello Allen,

Bleeds are pretty much everywhere with add-ons for Combat Flight Simulator. I think everything has bleeds to one degree or another. This project will have a few, but hopefully they will not be bad enough to be seriously distracting. A lot of it is because Aircraft Factory 99 is the most common tool.

I figure a nicely shaped aeroplane is a matter of artistry. A bleed free aeroplane is more a matter figuring out how to use the tools to eliminate bleeds. When trying to rework an existing project, I prefer well shaped. As you can see by THIS project, the bleed issue can be reduced just by rearranging things a bit.

I also cheated a bit a couple months ago:
A while back, my friend Smilo was commenting that there wasn't a nicely shaped P-38 available that didn't have significant bleeds. I had found Eric Johnson's AFX quite some time ago and was pleasantly surprised that most of the dimensions were quite accurate. I decided to rework it for Smilo and along the way gathered enough information to build my own DP File and AIR File.

While doing the reworking of Eric Johnson's P-38J, I experimented with ideas in assembly and to see whether or not this project was feasible using my own build methods. The result was a "Maybe but with Great Difficulty". (Actually the answer was a "No", but that kind of answer is unacceptable.)

His aeroplane is mostly 8 sided sections while mine is mostly 12 sided. Mine is also a considerably more complicated design with more pieces.
I finished the rework of his project with a Parts count of around 770 and Component Count of 30 but the Cockpit remained empty.

I was hoping that my solution to the Coolant Radiators was enough to leave me some extra working room.

We shall see soon whether it was enough.

With a reasonable DP File and what I thought at the time was a pretty good AIR file, it seemed a shame not to try to build my own visual model for a complete aeroplane of my own.

- Ivan.

[Ivan]

A Wing Fillet was added to each side to cure the Nacelle bleeds through the Inner Wings. The effect would have been the same but with 20 fewer Parts and 2 fewer Components if the Fuselage to Wing Template had worked.

Adding the Wing Fillet also added yet another bleed. It will cause a bit more difficulty when adding Flaps because the inner Flap sections begin at Wing Station 8 which is in the Fillet area and in a different Group than the rest of the inboard Flaps.

The one good result is that there is now a slight fairing between the Nacelle and Inner Wing at the front.

To cure the new bleed and address the other severe bleed from a rear view, The main section of the Horizontal Stabilizer was changed from Left-Right sections to Left-Center-Right sections. There is quite a lot of flexibility in choosing where to make the cuts: They just need to be outboard of the Wing Fillets and inboard of the Coolant Radiators.

The last screenshot shows the result.
The Parts Count is now 1122 of 1200.
The Components Count is now 28 of 30 with the 3 new Components at each Fillet and the Tail.

This project now has only 78 Parts remaining for quite a lot of missing pieces. I should have kept things a bit simpler or go back and see what can be done more economically.

- Ivan.

[Ivan]

The P-38 Lightning was equipped with Fowler Flaps which greatly increased the Wing Area and could be used as "Combat Flaps" when partially extended.
When fully extended, they appear to just clear the trailing edge of the Wing with a noticeable gap between the Flaps and Wing.
Full Extension is 45 degrees.
Total Area is 42.60 Ft^2.

The Inboard section on each side starts at Wing Station 8 and extends to Wing Station 77.
The Outboard section on each side starts at Wing Station 118-3/4 and extends to Wing Station 180.

The Outboard Flap sections have a chord of 23.5 inches.
From doing some quick math, the Inboard sections also appear to have a 23.5 inch chord.

The Screenshots show 3 Flap sections per side because of the need to separate the Inboard section into a piece for the Body, Main group and one for the Inner Wing group.
The Body Main (Wing Fillet) pieces would disappear at certain angles and caused enough bleeds that I will be leaving them out until I can find a better solution.

Also added was a set of Elevator Mass Balance weights. They are not particularly complicated but cost another 8 of the increasingly scarce Parts.

I believe that in order to display and animate the Flaps properly, 6 Parts are required for each section that is built.
A Flap Well which is an "Insignia" Part facing Down.
A Upper Flap surface which is interior coloured (Probably Light Green for Zinc Chromate or perhaps Gray for Aluminum.
A Lower Flap surface which matches the bottom of the Wing and is textured the same as the Wing.
....and the 3 Glue Parts required to locate the actual Parts properly.

- Ivan.

[Ivan]

Bleeds betwen the Inboard / Outboard Wing sections and the Cowl Component were fairly simple though tedious to solve.
The basic idea was to extend each Wing Part until it slightly overlapped the Cowl.
(The Inner Wing Bleeds were actually changed a while back at the time the Wing Root Fillet Components were added.)

In the case of the Outer Wing, a slight change was made to the adjacent Cowl and Boom Parts.
(The Vertex was moved 0.20 Feet Up to line up with the extended Wing panel.)
I knew this change would be necessary at some point which is why I tried to create Left and Right side Cowl and Boom Components as "Opposite".
I was a bit surprised at how small the actual change was and how hard it is to see if you are not looking for it.

The end result cost no additional resources but with the previous changes we now have
1134 Parts
28 Components

- Ivan.

[aleatorylamp]

Hi Ivan,

I am following this thread with great interest, as it addresses many problems I have found with wings, i.e. where they meet cowlings, nacelles, fuselage or booms, and provides interesting solutions!

Thank you very much indeed for your arduous work!

Aleatorylamp

[Ivan]

Thanks Aleatorylamp,

Glad someone is getting something from this thread. I am getting the impression there is a much bigger audience than I had first expected. I had figured it would be the same crowd that hangs out at the "Conspicuous by Their Absence" thread.
As you can see, this is proving to be a bit more challenging than most projects.

- Ivan.

[Ivan]

I decided that the bleeds that were being covered by the Wing Fillets had too many other side effects and expended too many resources that could be used elsewhere and so they were removed.

The biggest problem with the Wing Fillets was that they made it very difficult to build the inboard Flap sections without bleeds.

The Cowl Intakes and Nose Gear Door were also added.
The Nose Gear Door on the Lightning is asymmetrical probably because there needs to be clearance for a fork on the Port side but not on the Starboard side. The longitudinal location of the Nose Gear Door is about 2-4 inches further aft according to sketches, but i moved them a bit to line up better with the lines in the model and also to give better clearance for the strut.

Accuracy can't be very good here because a 2D Part is being used to represent a very curved piece. The same will apply to the Main Gear Doors when they are built.

The Cowl Intakes on the Lightning have 3 openings.
The Center opening is for the Intercooler which exhausts at the bottom of the Cowl.
The two Outer openings are for the Oil Coolers which have their exhausts on the cheek of each Cowl.

Besides the two Wing Fillet Components that were removed, a new Component was added at the upper rear section of the Nacelle to cure a bleed problem there. It fixes most of the Canopy Frame bleeds but as can be seen in the screenshot, some of the side frames still vanish at certain angles. They can also be addressed if any Parts are left over.

All the Flap Parts are now in place. Note that this created a bleed of the upper surface of the Inboard Flap section through the nose.
If the Fuselage to Wing Template worked as expected, this would not be an issue at all.
Note also that this Flap bleed is not as bad as it looks because the Animation sequence can be adjusted to not display the Part when Flaps are fully retracted.

The overall screenshot shows the current status and quite a few missing pieces.

Parts Count is now 1153 of 1200
Component Count is now 27 of 30

- Ivan.

[Ivan]

They are two tear drop shaped curved scoops under the trailing edge of each outer wing.
These are the Intake Fairings for the superchargers on the Lightning.

Most models of the P-38 had two sets of superchargers:
The most obvious was the round / spiral shaped burned metal object on top of each Boom which was the Turbo Supercharger.
It was powered by engine exhaust which was piped from the outside of each cylinder head to a collector / plenum on top of the Boom just behind each engine. The plenum fed the Turbo.
This is also a recognition feature between Early and Late production versions of the Lightning.
The British contract Lightning Mk.I aircraft simply had no Turbocharger at all and were poor performers at medium to high altitudes.
The early model Lightnings had a noticeable gap between the exhaust plenum and Turbo because part of the ducting was hidden under sheet metal.
The later model Lightnings had all of the ducting exposed between where the collector and the Turbo.

In constructing the Intake Fairings, I found that I had run out of Parts.
The 3 unused Components were expended for the aircraft's Wheels which were Structures.
Each Wheel as a Structure uses 30 Parts.
Each Wheel as a Component uses 12 Parts.

Each Intake Fairing is an 8 sided Structure in 3 sections and costed 25 Parts.
The intakes are located vertically on the Fuselage Reference Line and so I built them on the model's vertical centerline.
I was surprised when there was an overlap between each Outer Wing and he Intake Fiairing.
I went back and forth a few times to check dimensions until I realised that my model centerline is 0.42 Feet above the FRL.
When I made that adjustment things looked a LITTLE better but the Fairing still looked in the way to block the outer Flaps.
THEN I remembered that the P-38 has Fowler Flaps which move back as they extend. There isn't much clearanc but there is some.

Also worth noting is that AF99 seems to have an inconsistency in handling Structures:
The colour is as specified if neither the Forward or Aft Bulkhead option is selected. (Cockpit Dash area)
If either Forward, Aft, or Both Bulkheads are selected, the Structure uses the Group Colour but the ends are the colour selected for the piece.

Parts Count is 1173.
Components Count is 30.

There are still
Landing Gear,
Pitot Tube,
Guns,
and some other Minor details I still want to add.
It will be very close.

- Ivan.