Lockheed XP-38 for FS2004
by David C. Copley

Version 1.3 (Project XP-38N ver. 4.xp.1.3)
1 Nov 2003

Contents

Installation

Project XP-38N

Facts about the Lockheed P-38

Facts about the XP-38

The visual model

Flight dynamics

Flying Hints

Acknowledgments

References

Usage / Distribution / Permissions etc.

About the Designer

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Army artist's depiction of the XP-38 in flight.  No actual in-flight photos were ever taken.
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FS model of the XP-38 in flight over Burbank, CA.
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One of the few photos of the completed XP-38.  This photo was taken at Dayton Ohio, where the plane had stopped for refueling during its final, historic flight.  A few hours later the plane crashed in New York.

Installation

1) Unzip the downloaded file and extract (or copy) the XP-38 folder to FS2004's Aircraft folder.  Several sub-folders will be created.
2) Copy the gauge in the gauges subfolder to FS2004's gauges folder.
3) Copy the files in the effects subfolder to FS2004's effects folder.

Important Notes

1) This model is intended for FS2004 only. 

2) The visual model makes extensive use of so-called 'reflective textures.'  Be sure this setting is ON in FS2004.  The setting can be found through the main menu by selecting Options / Settings / Display ... / Aircraft tab, "Reflections." as shown in the image below:

This setting may adversely affect display performance, but is essential for the model to look as intended.  I also recommend setting the aircraft textures size to Massive to see the details, but again, this affects display performance.

3) Landing light: the real XP-38 did not have a landing light but I have included one because I like night flying.  However, to maintain the original look of the plane, I made it a fold-out light in the nose.  Use the spoiler command (typically '/') to deploy/retract the light and then use the standard Landing Light command (Ctrl+L) to turn it on/off.  Note that you can adjust the aim of the beam with ctrl+shift+[num pad number] (Num lock must be off).

4) Occasionally I experience unpredictable behavior with these light switches.  If you have any trouble with them (such as the panel lights being turned off when you turn the landing lights on, or the tail strobe is not illuminating the tails) try the the all-lights-on command (typically the 'L' key) and then use the switches.

5) The fuel tank selector gauge does not work properly in FS2004.  It is a carry-over from my CFS2 P-38s, and is included only for cosmetic reasons.  Thus, use automated fuel management instead of manual fuel management. 

And finally ...

I have attempted to model the XP-38 how it looked the day of its historic final flight in early 1939. However, to meet my personal flying preferences, I have added a few modern conveniences. I like to think of this as a model of a modern restored XP-38.

Be sure to visit www.kazoku.org/xp-38n for the latest updates, more P-38 models, and lot's of P-38 pictures!


Project XP-38N

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Image of XP-38N version 3.2 in FS2002

Project XP-38N is my on-going effort to model what might have been the next version of the P-38 had the war not ended. (The last production model was designated 'M', so if there had been another, it would have been 'N'.)  My first version was for FS98 and later versions subsequently supported CFS1, FS2000, CFS2 and FS2002.  Beginning with version 3, I used the base model to create late model production variants.

For version 4 of Project XP-38, I set out to build every major variant (as deemed by me) plus this very special XP-38. Having completed the task for FS2002, I am now converting the models to FS2004 and including a few new features.


Facts about the Lockheed P-38

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The Lockheed P-38 Lightning was one of the most prominent fighters throughout WWII in both theaters of operation. P-38s scored the first kills in the Pacific Theater as they served in the arctic cold of Aleutian Islands. In Europe, they often provided high-altitude long range escorts for bombers.

The P-38 was originally developed in response to the US Army Air Corps' need for a high altitude 'interceptor' in the late 1930s. The Air Corps' requirements specified a craft that could reach an altitude of 20,000 ft in six minutes, attain a top speed of 360 mph and fly at full throttle for one hour. In addition, it would carry more armament that any previous fighter.

Lockheed's legendary aeronautical engineer, Kelly Johnson, drew on his past experience with twin-tail craft such as the Electra and proposed a twin-engine, twin-boom arrangement with turbo-supercharged engines. (Kelly Johnson went on to design the F-104, the U-2 and the SR-71.)

The XP-38 was first flown in January 1939. After logging just 11 flight-test hours, it embarked on a record-breaking cross-country flight that proved the capabilities of the design, but also lead its demise when it plowed into a golf course just before landing.

The only fighter-craft to remain in production throughout the war, the P-38 proved to be a very versatile platform for a wide range of operations including long-range escort, photo reconnaissance, fighter/interceptor, ground attack, and even formation bombing. It evolved through several variations, each iteration more successful than the last.

Perhaps its strongest asset was its concentrated fire power. Being a twin engine aircraft allowed it to have four guns and one cannon mounted in the nose. This clustered arrangement meant that the guns did not have to be sighted to converge at some optimum target range. In the hands of skilled pilot, the Lightning was a formidable fighter. No wonder America's top two fighter aces scored their victories in P-38s.

However, it was not without its faults. Early into the European war it gained a reputation for poor high altitude performance. Even though this was eventually traced to the use of lower-grade British fuels, the reputation remained. The two liquid-cooled Allison engines required a lot of attention, and there was trouble with the turbo superchargers as well. The P-38 was the first aircraft to seriously encounter a potentially fatal phenomenon: compressibility. During a high-speed dive the wings would lose lift, resulting in loss of control. The enemy soon began exploiting this weakness to elude the P-38s. The problem was finally solved when, late in the J series production, dive recovery flaps were added which gave pilots the freedom to enter into high speed dives with confidence. Early Lightnings also had poor roll rate and required a lot of muscle to turn.  When the dive recovery flaps were added during the J-25 production block, hydraulically boosted ailerons were also added.  This welcome addition gave pilots "power steering," greatly increasing the roll rate.

As the need for night fighters increased, Lockheed produced the two-seater M series. The addition of a radar operator relieved the pilot from radar duties and allowed him to concentrate on the mission objectives.

Nearly 10,000 P-38s were built, the bulk of which where J and L series. After the end of the war, the Army Air Force surplused them for $1,200 a piece. Of course you had to arrange for delivery, which was no trivial task since as many of them were in the south Pacific. Today, only a handful remain. Only a few are in flying condition.


Facts about the XP-38

As mentioned above The XP-38 was Lockheed's entry into the US Army's competition for a new generation pursuit plane.  Lockheed had never developed a fighter aircraft before, but the fledgling company had great confidence it could deliver.  After proposing the radical concept of a twin-engine, twin boom fighter and being awarded $163,000 to build a prototype, Lockheed then invested $761,000 to develop and build the XP-38 -- a tremendous gamble on the part of the relatively new company, especially since there was never any expectation that the Army would need more than perhaps 50-100 planes total.  (At that time, a Packard coupe cost about $900, and a new 2-bedroom home in California cost about $3,000.  Thus, one can see that Lockheed was betting its future on the success of this plane.) 

Well ahead of its time, the XP-38 was one of the first to include features now common in modern aircraft, such as Fowler flaps, butt-jointed flush-riveted skin, metal control surfaces, tricycle landing gear, and a bubble canopy.  The prototype was almost entirely hand-made and its aluminum skin was highly-polished.

The XP-38 rolled out December 31, 1938 under intense security. After many taxi tests throughout the month of January, it made its first flight January 27, 1939.  The first flight was troublesome and nearly ended in disaster.  Almost immediately upon take-off, the flap mounts broke and caused dangerously severe vibrations.  Lt. Ben Kelsey, a highly skilled pilot who had been with the P-38 program from its inception, brought the plane under control and returned to the airstrip.  After some repairs it took the skies again, and the Army soon realized they had the fastest fighter plane in the world in their hands, capable of sustained speeds of over 400 mph. 

Kelsey and his superiors felt that they could break the cross-country speed record of Howard Hughes.  Such a feat would definitely gain support for the new fighter.  It was decided that he would make the attempt so far has Dayton, Ohio where he was based and if all was well with the craft, he would be allowed to continue to east coast. 

On the morning of February 11, 1939, Lt. Kelsey took off from March Field in the California desert and made a fuel stop at Armarillo, TX before reaching Dayton.  At Dayton, it was decided that while he couldn't beat Hughes' total elapsed time (due to the refueling stops) he could easily break the flight time.  The plane was looked over and Lt. Kelsey was given the go ahead to finish the cross-country dash. 

On approach to Mitchel Field on Long Island, NY, Kelsey throttled back the engines and began his descent.  No one had thought to tell Mitchel Field of this very special arrival (after all the XP-38 was a secret military plane), so when he called in for landing clearance, he was put into 4th position behind some rather slow moving planes.   While on the very long base leg ice formed around crucial engine systems so much so that when he came into final and attempted to increase power, the engines did not respond.    Kelsey couldn't quite make the runway and ended plowing into a golf course.  Fortunately, he walked away unhurt, but the one-of-a-kind XP-38 was damaged beyond repair. 

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In total, the XP-38 had just under 12 hours of flight time when it crashed, with the majority from the cross-country flight.  However, it had proved its point: it was fast!  And it was a good design.  Not long after the crash, the Army ordered 13 service test YP-38s, and the rest is history.  Because of the XP-38's relatively short service life, not much is know about its actual performance specifications.  Also, there are only a handful of photographs -- none of it in-flight. 

The XP-38 was different than most of the subsequent P-38 variants.  For instance, it had a full wheel for aileron control (instead of the 3/4 wheel and yoke found on successively later variants).  The use of the C-series Allison V-1710 allowed for a tight-fit tapered cowling and excellent streamlining around the engine.  Necessary system appendages (scoops, vents, radiator housings, etc.) were far smaller than on subsequent variants, all attempts to minimize drag and maximize aerodynamics. The propeller spinners were 'pointier' and the propellers -- while counter-rotating like most P-38 variants -- spun the opposite directions (highpoint inward, instead of highpoint outward as found on all subsequent variants).  (The French/British Lightnings, of which there were very few, did not have counter-rotating propellers). 


The visual model

For any FS model, there can be up to four aspects of the visual model: 1) external geometry, 2) textures (paint), 3) 2D panel and 4) virtual cockpit.   My design is intentionally a balance between computer performance, modeling time (that is, the time I can dedicate to this hobby), aesthetics, detail, etc.

External Geometry

The model was built in FSDS 2.  (The final model was compiled with FSDS 2.2.4.)  

The external model has the following animated features:.

*There was no control of the nose wheel on any of the the real P-38s.   Steering was accomplished with differential braking and differential thrust.   The nose wheel was a caster, and simply moved like a shopping cart's front wheels.  But my XP-38 has rudder-control steering!

Textures

As mentioned in the Installation Instructions, FS2004-specific reflective texturing has been used to great extent in order to simulate the highly-polished aluminum skin.   Not being a graphic artist, my textures are always on the simple side, but I believe they are effective in establishing the essence of the look and visual 'feel' of the aircraft.  I made extensive use of 3-view plans from various P-38 books (see References) as well as PaintShop Pro to make these.  Some of the image details come from digital photographs I have taken of a real P-38 (for example, the wheel image is from the P-38L at Oshkosh, the radio boxes are images of a real P-38 radio at another museum, cockpit controls from "Glacier Girl" etc.), and other real-life objects (an image from a Saturn V makes a cameo appearance, can anyone find it?), and some of the cockpit images were 'borrowed' from the stock P-38F in MS CFS2.

2D Panel

My objective for the 2D panel design was what one flight-sim designer has dubbed "functionally realistic." The layout is based on  photos of the XP-38 mockup panel (made of wood) as well as photos of the the YP-38 panel.  I have re-arranged a few items for practical purposes.  The bitmap is a modified version of CFS2's stock P-38 panel.   I've included the default GPS and a separate pop-up window with a few modern navigational aids for simple IFR flying.

Virtual Cockpit

My previous P-38 models had very simple virtual cockpits (VC) for computer performance reasons and because I did not use VCs much.  Having invested in a higher-performance computer, I decided to make this virtual cockpit more detailed because I am beginning to like using the VC for many aspects of flying (I particularly enjoy it for landings).  This VC may not be as detailed as it will become in later versions for two reasons: I am still learning and experimenting, and I envisioned the cockpit in the real XP-38 as not being too cluttered with the peripherals of a battle-ready aircraft. 

The VC includes dynamically-functioning gauges and levers, control yoke and many of the features found in a real P-38 cockpit, such as the radio boxes behind the pilot and miscellaneous switches.  I thought about putting in a cup-holder or two... :-) 

(Please note, not all gauges in the VC are functioning.  Some of the engine gauges were replaced with static bitmaps to improve frame rates.)

Sounds

I make my living working with sound.  So for me sound in a flight sim is a very important element.  Ever since I began this project in 1998, I have always wanted to create a sound package from actual P-38 sounds that I recorded, mixed and mastered myself.   I have used and modified some great P-38 sound packages over the years for my own purposes and occasionally for sharing, but I had a longing to record a real P-38 and make a P-38 sound package from scratch with my own sounds. 

On October 26, 2002, I had the privilege of attending the first flight of a newly-restored P-38F-1-LO.  Dubbed "Glacier Girl," this rare bird had been recovered from the snow and ice of Greenland and restored to perfection.  Drawn like a month to a bright light, I made my way to Middlesboro, KY to see and hear a P-38 fly for the first time in my life.  Naturally, being a professional acoustical engineer, I brought some recording equipment with me. :-)

I obtained quite a number of recordings, but the best came from single-engine tests several hours before the flight.  However, there were literally thousands of people there, and as a common bystander I could not get too close to the plane (though I did have a front row spot!).  So, most of the recordings I brought home have people talking loudly over the almost musical purring of the Allison and Curtis Electric prop. 

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(Photo by me.)

I employed several tricks of the trade and managed to extract the sounds you hear in this model.  I mixed in the turbo-supercharger sound per my imagination because, well I felt it needed it.  (I'm not sure the turbos were even engaged on Glacier Girl, as I could not pick them out during the single engine test nor during the flight.  It could be that the rpm's were never high enough to hear them, or they were simply not plumbed into the exhaust system.  I have been informed that the P-38 at Chino, CA does not even run with the turbos, as it never gets up to altitude where they're needed and they're quite a mechanic's nightmare to maintain.)

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Flight dynamics

I readily admit that I am not a pilot. Ironically, I actually hate real-life flying and avoid it whenever possible. But I can spend hours and hours flying my P-38!!!  (I even flew it around the virtual world!)

In many respects I have been working on the flight model longer than any other aspect of this model.  Project XP-38N began in 1998 and this flight model is distant relative of the very first flight model I developed.  Early versions of XP-38N used FS98-AIR files.  I spent hundreds of hours developing those AIR files and I didn't want to give them up.  For XP-38N version 3.0,  I successfully transferred many of the old parameters to a CFS2-based AIR file and then made adjustments until it flew pretty much the way I wanted it.   Also, a major part of updating the dynamics from version to version was accomplished when I modeled the P-38L.  For that, I sought some help.

First, I obtained P-38 videos and printed references that I studied carefully (and continue to study).  Second, I sought help from those who actually flew the plane.  I have had the privilege of corresponding with a former P-38 pilot, Lt. Col. (ret) William C. Sharpsteen II, who flew with the 339th FS/ 347th FG in the South Pacific.  Mr. Sharpsteen has taught me much about the handling of the P-38, in the air and on the ground, and about the differences between the earlier G model, which he spent quite a bit of time in, and the late J-25/L, which he also flew. 

The flight model for this XP-38 model is a conglomeration of aspects from my previous models, tailored to the unique characteristics of the XP-38, plus a few new techniques I have developed. 

The flight model was designed and tested in FS2004 with full realism applied.  During certain maneuvers above 400 mph the plane will buffet a bit.  This is intentional. While the actual plane may not have buffeted exactly like this, I am trying to simulate the fact that it did have a tendency to buffet at high speeds as indicated in the actual flight manual for later variants.  The actual XP-38 buffeted quite a bit even at lower speeds (a problem eventually solved in later variants) but I did not want to model every quirk of the original prototype.  After all, I'd like to be able to enjoy flying this thing!  You will also note that at most speeds, it is very difficult to stall, which was apparently true of the actual airplane.

I do not claim this to be the best or the most accurate flight dynamics model for the P-38, as flight dynamics modeling is still somewhat of an art.  However, I do believe I have captured the essence of the early model P-38.


Flying Hints

Best taxi speed is below 50 mph. Use differential braking (F11 and F12), differential thrust or the nosewheel for steering. For best results, use a combination.  For tight turns, slow down to just a few mph.

Rotation and lift-off occurs about just above 100 mph (no flaps).  Retract gear as soon as you can. It likes to cruise between 270 and 300 mph IAS, depending on altitude.   At those speeds use trim liberally for level flight.  Be sure to cut back on the fuel mixture if you want to fly for any great distances.  Max speed is about 420 mph (TAS), though you may be probably push it a past that in a dive before buffeting begins. Max distance is about 1,400 miles. 

The model's kneeboard checklist and reference tab provide some operating instructions and information.   Some of the verbiage is directly from the P-38's pilot manual.  To view these press F10.  


Acknowledgments

Beta Testing/User Input

The following individuals have provided testing and technical assistance with the Project XP-38N version 4 models (XP, F, G, H, J, F-5, L and M).

Special thanks to Dave Bitzer for his valuable feedback on fuel consumption and power settings.  Dave also provided help with the checklist, reference card and IFR navigation instruments.

Gauges

Most of the gauges are from CFS2's stock P-38 (gauge file is included in FS2002 Pro and FS2004) but the bitmaps have been modified by me to look 'cleaner,' 'newer,' and 'less used' to fit with my 'restored warbird' motif.  A few gauges from other stock FS2004 planes are used as well.

Resources / Influences / Other

avhistory.org - for their methods and AirEd.ini file and development tools.  While I did not employ their "Assembly Line" or "1%" process, I admire their methodical and scientific approach and have learned much from their work. 

Netwings and Sim-outhouse, AVSIM, FlightSim, and all the great PC-aviators that contribute to the forums.

Special thanks to my family for putting up with my P-38 obsession!


References

Books on my library

Interviews

Web pages

Videos in my library


Usage / Distribution / Permissions etc.

This model is released as FREEWARE.  If Freeware can be copyrighted, then I claim Copyright © 1998-2003 David C. Copley.  This package, including each and every file, may NOT be included in a commercial package.

Normally I  grant permission to freeware developers to repaint my models.  But this plane is so unique, so special to the history of aviation and to myself, I would ask that it NOT be modified, repainted, or even uploaded to any site as is.  In other words, I want to retain control of all aspects of the model.  I am especially sensitive about the engine/propeller sounds.  I invested a bit of my free time and money to travel to south eastern Kentucky to acquire those sounds and I hope the flight sim community will respect my wishes to maintain control over them. 


Project XP-38N Version History

1 Nov 2003 - XP-38 ver. 1.3 FS2004 update

13 Oct 2003 - "P-38M Night Lightning" (P-38M-6 version 2.0, Project XP-38N version 4 phase 5) for FS2004

13 Oct 2003 - "P-38M Night Lightning" (P-38M-6 version 2.0, Project XP-38N version 4 phase 5) for FS2002

16 August 2003 - "P-38L: The Definitive Lightning" (P-38L-5 version 2.0, Project XP-38N version 4 phase 4) for FS2002

12 August 2003 - "P-38L: The Definitive Lightning" (P-38L-5 version 2.0, Project XP-38N version 4 phase 4) for CFS2 (Limited Release)

21 June 2003 - "P-38 Pair" (J and F-5 version 2.0, Project XP-38N version 4 phase 3) for FS2002

1 Mar 2003 - XP-38 ver. 1.1 (Project XP-38N version 4 phase 1, minor update)

8 Feb 2003 - P-38 Triple Play (F,G and H) (Project XP-38N version 4 phase 2) for FS2002

1 Feb 2003 - P-38 Triple Play (F,G and H, Project XP-38N version 4 phase 2) for CFS2

20 Dec 2002 - XP-38 ver. 1.0 (Project XP-38N version 4 phase 1)

14 June 2002 - XP-38N ver. 3.2

26 Jan 2002 - XP-38N ver. 3.1

14 Jul 2001 - XP-38N ver. 3 (CFS2 and FS2000 versions)

21 April 2001 - P-38L: ver. 1.1.0 (XP-38N ver. 3 Phase 2) for CFS2

28 Mar 2001 - P-38L 1.0.0 (XP-38N ver. 3 Phase 1) for CFS2

22 Apr 2000 - XP-38N ver. 2 for FS2000

17 Jan 2000 - XP-38N ver. 1.1 for FS98/CFS

20 July 1999 - XP-38N ver. 1.0 for FS98

Sep 1998 - began Project XP-38N


About the Designer

By day I am an acoustical engineer for a major industrial company.  By night (when I'm not spending time with my family or engaged in other real-life activities) I am a P-38 nut.  I am also a musician, so my 'free' time is split between flying/making P-38s and making music.

You may contact me at db@kazoku.org, or visit my web site www.kazoku.org/xp-38n.