This article first appeared in the April 2019 issue of Warbirds.
“A lot of people assume that NAA (North American Aviation) simply took two P-51 Mustangs and slapped them together — this couldn’t be farther from the truth. In fact, there are less than a handful of parts that are interchangeable between a P-51 and the P-82 Twin Mustang. The elevator trim wheel, the canopy crank; the stick grip is the same but not the bar; the horn on the bottom of the rudder and the rudder trim tab hinges; and the hydraulic accumulator and half the tail wheel. I’m not talking about nuts and bolts and pulleys. I’m talking about specific parts. When I took on this project over 10 years ago, I figured it would take four to five years and X number of millions of dollars to complete. After I read Edgar Schmued’s (NAA designer of the P-51 Mustang) book I realized I was way off. The NA-73 (P-51 Mustang) took 204,000 engineering hours to complete to the first flight. The XP-82 took 1,470,000. Seven times as much. I guess I should have read the book first. But we’re almost done, and although it’s been a long road, this restoration has been nothing short of magical, and I know thousands of people who can’t wait to see the XP-82 fly again.” — Tom Reilly
XP-82 Design and History
In1943 with a world war raging on all fronts, the Allied military planners knewthat in order to gain supremacy over the Axis they needed to hit the enemy’sindustrial targets deep inside of both Europe and Japan before they couldconcentrate on any invasion planning. The B-17 Flying Fortresses and B-24Liberators in Europe already had the range, but fighters like the P-38Lightning and P-47 Thunderbolt could only escort them so far before having toturn back, leaving the bombers unprotected. The P-51 Mustang had yet to come online. The Pacific theater was much worse with no forward bases close enough tolaunch aircraft from to attack the Japanese mainland. A new wonder weapon, theB-29 Superfortress would soon be coming on line, giving the Allies the abilityto strike Japanese homeland targets, but it would have to go it alone with noother fighter escorts because none of the current inventory had long enoughlegs to make the exhaustive round trip.
NorthAmerican Aviation Assistant Chief Designer Edgar Schmued, famously known as theprimary designer of the P-51 Mustang, was tasked once again with coming up withthe required design and solution for a long-range escort. Schmued and hisdesign team narrowed its focus to two different proposals. The first was atwin-engine, single-seat fighter supported by tricycle gear. The secondproposition was a more radical design comprising two fuselages, each housing apilot and Packard-built inline 1,860-hp Rolls-Royce Merlin engine. The twinfuselages were attached to a 400-square-foot wing housing six .50-calibermachine guns. This design became the genesis of the P-82 Twin Mustang.
When the military camecalling on NAA in November of 1943 it was already planning and focusing on aninevitable and costly invasion of Japan. Gen. Hap Arnold was quoted as saying, “Weneed an airplane that’s 50 mph faster than any current fighter and has sixhours further range and will be able to cruise with the B-29s.” A B-29 willcruise at 300 mph. The Mustang will cruise at 245. The P-82 will cruise at280-300 mph. That was a whole bunch closer to the B-29.
But the P-82 not only hadto have speed, it had to be a flying gas tank as well. With an internal fuelload of 600 gallons, plus two 310-gallon drop tanks, the Twin Mustang had acombat range of 2,700-3,300 miles depending on throttle settings. This was theairplane the Allies needed to help win the war as a large order was placed bythe Army Air Forces. By the time production began and two prototypes werebuilt, along with less than a handful of others, the war was winding down andthe need for long escorts had been solved in the Pacific with the capture ofnearby Japanese-held islands. A scaled-back production schedule was initiatedalong with an engine change.
“Because the British wanteda $6,000 royalty fee for each Rolls-Royce Merlin engine, the military thumbedtheir noses at that prospect and selected the 1,600-hp Allison V-1710 enginesto power the later model F-82s,” Tom said. “They were somewhat reliable butwere not as powerful as the Merlins.”
After the U.S. Air Forcebecame an independent branch of the military in September of 1947, the letter Pfor pursuit was changed to F for fighter in June of 1948. The F-82 eventuallysaw heavy service in Korea, filling the gap and holding the line. The F-82 heldthe distinction of shooting down the first three enemy airplanes of the war.But with the advent of the jet age, the F-82 was no match for MiG-15 fightersand had to pass the torch to the next generation of North AmericanAviation-made fighters — the sweptwing F-86 Sabre jet.
“When the Sabre came along,the life of the F-82 was limited,” Tom said. “Most were sent to a combat patrolenvironment in Alaska. Fourteen F-82s — modified, winterized H model versions —were stationed there, and they had the large radar pod mounted in the centerthat stuck out beyond the propeller, so the propeller wouldn’t interrupt theradar signal. The interior changed as well as the pilot in the left fuselagehad full controls, but the co-pilot on the right side had the responsibility ofmonitoring the electronics. The sad fact was, when the Air Force determined theF-82s were no longer operational, many were simply scrapped: 248 of the 272built were scrapped, 13 were lost in Korea, five were lost stateside, and onewas lost in Alaska, [which wasn’t yet a state].”
Of the first two XP-82 TwinMustangs built by North American Aviation in 1945, only one survived thescrapper’s torch. The first airplane, 44-83886, accumulated less than 300 hoursat PAX River before being scrapped in 1955. XP-82 44-83887 — although beat up,bent, and battered — had a somewhat better career and a brighter future.
“Our airplane, 83887, went to NACA (the predecessor of NASA) in Cleveland, Ohio, immediately after its first flight on April 15, 1945, sometime in August or September of 1945,” Tom said. “It was a test bed for an eight-machine gun center pod, underwing rockets, and a radar pod. It flew with NACA, from mid-1945 until December 15, 1949, when it skidded off the side of an icy runway, buried itself in the mud, and bent the center section. The military said, ‘Well, we don’t need it anymore.’ They already had a second P-82 so they simply scrapped it. A soon to be very well-known aircraft collector from Newbury, Ohio, named Walter Soplata found out about the slightly bent XP-82 before the military could scrap it and paid $300 for the airplane and hauled it to his Ohio farm.”
Reclamation, Rescue, andRestoration
The son of Czech immigrants, Walter — of Newbury, Ohio,located just east of Cleveland — began collecting discarded airplanes in 1947.These included a BT-13, BT-15, T-50, T-28, SNJ Texan, FG-1D Corsair, F2GCorsair, TBM Avenger, AD Skyraider, F-82E Twin Mustang, P-80 Shooting Star,F-84F Thunderstreak, F-86L Sabre, F7U Cutlass, B-25J, Douglas B-26, a P2VNeptune, C-82, B-36, and the prototype North American XP-82 Twin Mustang — toname just a few. Walter was not a pilot — more of a visionary in a sense as heunwittingly helped preserve our nation’s history while the short-sightedmilitary considered many of these airplanes as throwaways. But the military wasfar from finished with the Twin Mustang.
“When Walter took possession of the XP-82, the militarykept the propellers and engines and left him with the remains,” Tom said. “He unbolted the outboard wings and cut the center section apart witha torch and moved the airplane to his property in Newbury. Shortly thereafter,when the Korean War started, they came back to him and said, ‘We need theairplane back to test it to destruction because a bunch of these airplanes aregoing to Korea.’ They traded him an F-84 for the right-hand fuselage and centersection, and the outboard wings and the tail.”
Tomfirst met Walter in the early 1990s when he was called to the farm to performan IRS appraisal on one of Walter’s aircraft. While roaming the grounds Tom atfirst thought he spied a P-51 Mustang, until he did a double take and realizedit was an Allison-powered F-82E Twin Mustang. At the time Walter had not toldTom that what he had was the second-built XP-82 along with all the parts thathad come back from NACA after they had crushed the right-side wings and tail.
“Ifirst thought all he had was the left fuselage. I knew that if I was ever goingto realize this dream of rebuilding and flying a Twin Mustang, I would need tofind the ultra-rare left-turning Merlin engine and propellers and lots of othermissing parts and pieces,” Tom said. “That’s when I began to scour the Earthfor anything and everything P-82/F-82 related.”
Withmost of the XP-82 treasure hunt complete in Ohio, Tom trucked everything to hisshop in Douglas, Georgia, and began to inventory and document each and everyitem. He also contacted all of those individuals with assorted P-82/F-82 partsaround the country and obtained many of the needed parts for this massiveproject. With such a gigantic undertaking Tom also sought out airplanecraftsmen and women to hire to either repair, rebuild, or re-create all thehundreds of thousands of parts needed to make the XP-82 not only flyable, butone that was a real showstopper. Thisincluded replicating the grease pencil graffiti found inside of one of thefuselages, which included the likes of, “Henry will have the tickets for thetheater tomorrow” or “426AD4-6 rivet goes here” with an arrow pointing whereone shift left a note for the following shift. From tackling both fuselagesfirst to the horizontal stabilizer and working his way forward, Tom was laserfocused in his approach. If he didn’t have a particular piece or part, therewere times Tom would call upon fellow F-82 restorer Pat Harker to see if he hadalready overcome the obstacle or had the parts Tom needed.
“PatHarker has been incredibly helpful on this project,” Tom said. “I’ve visitedhis project several times, and his workmanship is nothing short of magnificent.I have taken countless photos and measurements, and he has helped us immenselywith not only trouble shooting our current dilemma or coming up with solutions.The one that really stands out was the MT propellers we both had made for ourprojects as the original Aero Products propellers were impossible to locate.”
Tombegan quietly contacting individuals with P-82/F-82 parts and paid a downpayment for a “right of first refusal,” telling no one of what he had discoveredin Ohio. Sourcing parts, Tom found a variety of individuals who had salvagedTwin Mustang parts from an Alaska scrapyard: three fuselages and three chunksof center section. There was another fuselage located in California, but theowner would only trade for P-51J parts — an NAA airplane rarer than the XP-82as only two were built. (Tom was able to locate a J model windscreen on theSoplata farm that Walter had bought years early, and he traded it for an F-82left-hand fuselage that had all the dual controls he needed.) There was a womanin Florida who had a P-82 canopy and countless others around the country withvarious bits and pieces. Parts aside, Tom’s main concern was finding thespecially made left-hand turning Merlin engine. Without it, Tom would have hadto install two right-hand turning engines on the XP-82.
Locatingthat engine was futile at best. On the verge of giving up, Tom located aleft-hand core, but the owner was reluctant to even part with that. Tom’s dreamwas just about to vaporize before his eyes on having a counter-rotating XP-82and putting on two right-hand turners when out of the blue his phone rang.
“Itwas Mike Nixon, owner of Vintage V12s in California, calling me out of breathand asking if I made an offer on the left-hand engine core yet,” Tom said. “Itold him I hadn’t, and he said good, don’t because he had just found a brandnew V-1650-23 still in the box in Mexico City. I didn’t even ask the price andtold him I would buy it.”
Toproperly describe and document the restoration of XP-82 83887 and what Tom andhis team have accomplished in the last 10 years would take volumes toaccomplish. But what was most evident speaking with him about this project wasthe fact that Tom Reilly doesnot live for shooting another rivet tomorrow, it’s to discover a problem thatcomes up and then find a solution to fix it. Tom likes to take projects thatpeople say can’t be done and restore them to flyable, award-winningrestorations.
Withtongue in cheek, Tom says he could have finished the XP-82 much earlier but heonly worked on it half days — 12 hours per day.
“Istill kick myself for taking that one Christmas Day off a few years ago,” Tomsaid. “I could be farther ahead if I had only worked on this airplane. Seeingthe light at the end of the tunnel and realizing it’s not a train is goodfeeling. But my main goal, before I pass on, is to teach as many young kids theskills needed to not only obtain their A&P ticket, but more importantlyhelp keep these vintage warbirds, like the XP-82, flying for future generationsto enjoy and cherish. Someone has to be the caretakers of them. As we are onlytemporary custodians of these priceless warbirds.”
Flying It
Tom had the Twin Mustang ready to fly in July 2018, but he wasn’t able to get it certified in time for EAA AirVenture Oshkosh. Around December 26, with all paperwork in hand Tom decided it was time to go fly.
“On December 31, 2018, we were to just do a high-speed taxi test, andit accelerated so fast that we found we were flying,” Tom said. “It acceleratedso fast it sort of surprised us. I was standing on the side of the runway atthe 2,000-foot mark, and he was only supposed to get a little bit of air underthe wings and then put it back down again. It accelerated so rapidly it poppedoff the ground. Ray Fowler, the test pilot, made the right decision to goaround, and he flew for about five minutes and it flew hands off, perfectly intrim, and it was definitely the highlight of my life.”
On January 28, 2019, the official first flights and test began. Thefirst five flights were intentionally made gear-down flights. With everythinglooking good, it was time for Tom to climb in the right co*ckpit.
“We had a couple minor little squawks, which was expected, and I got inthe right-hand seat on the fifth flight with the FAA’s blessing,” Tom said. “I’veflown Mustangs, but I never expected to feel the power that this thing had. Ithas 1,860 hp per engine compared to 1,500 hp for the Mustang, and it’s 3,700approximate horsepower and only about half again the weight of a regularMustang. So it accelerated dramatically fast and it climbed like crazy, so itwas a thrill. Sitting in the airplane, the anticipation overwhelmed mewith over 10 and a half years of labor, 207,000 man and woman hours to put thisairplane together. The exhilaration of how fast it accelerated, and thenclimbed out at about a 30-degree angle without even slowing down at all, it wasjust exciting that I can’t explain. I am overjoyed with how well it flies andcan’t wait to bring it in to EAA Oshkosh 2019.”
Reflections of a P-82 TwinMustang Test Pilot
Col. Bud Anderson (retired U.S. Air Force),357th Fighter Group ace and pilot of P-51 Mustang Old Crowwith more than 116 combat missions during World War II (without receiving asingle hit from enemy fire), returned home just before the war in Europe cameto a close and was assigned to Wright Field in Dayton, Ohio, as a test pilot.The following is his account of the P-82 test flight program.
One of my first programs as a test pilot was to run a performance teston the North American P-82E Twin Mustang. I don’t recall if I flew the XP-82while assigned to Wright, but I remember I also had P-82B time as well.
The early Twin Mustangs had Merlin engines installed, but the latermodels like the E were powered by two 12-cylinder, liquid-cooled, V-typeAllison engines equipped with speed density carburetors and water-injectionsystems. The co*ckpit was somewhat similar yet completely laid out differently.The landing gear handle was like the other one and in a similar location. Andthe flaps handle was generally in the same location as the other ones. Theywere similar or compatible.
The thinking back then was. “Well,one Mustang was great so if we put two together it’s gotta be better.”
Some of those first flights were visually interesting and perplexing;just sitting in the left co*ckpit and looking right and seeing this other masssitting across from you and you realize you’re flying formation with anotherMustang that’s attached to you. The Twin Mustang’s wingspan is 51 feet, 3inches and the fuselage length is 39 feet with the gross weight at 20,450pounds. In comparison, a standard D model Mustang has a 37-foot wingspan and alength of 32 feet, 3 inches and a gross weight of a little over 12,000 pounds.So the Twin was not only longer it was a lot heavier as well.
It had lots of power, especially with two engines as it had morehorsepower than a D model I flew in the war. Takeoff procedure was to hold thestick back to neutral to lock the tail wheel.
With the Mustangs’ long noses you still have to taxi in an S-turn. Andthen you have this other airplane S-turning with you, which you eventually justdeal with. I was always trying not to use too much brake or none at all. Theguy in charge always flew it from the left side. The E model had dual controls,and you could fly it from the right or the left. The night fighter was pilotedon the left side only, with the radar operator on the right.
When all your systems checked out and were in the green you began thetakeoff run by advancing throttles to 72 inches. With flaps up we lifted offaround 110 mph, and with 20 degrees of flaps our mains lifted at 100 mph. It wouldclimb out pretty good. It was heavier than a single-seat Mustang so it probablydumbed down the performance characteristics to that.
Single-engine operation was okay — just hold the airplane straight with rudder and feather the prop onthe failing engine. Adjust the power settings on the good engine and trim theairplane as required. No adverse effects at all as the other engine had plentyof power to get you back.
I did have a couple engine-outs once or twice — I can’t remember why,but I did and it flew fine on one engine.
Landings were a nonevent. Flaps to 10 then 20 degrees on base leg below200 mph. Full flaps (40 degrees) on final maintaining a gliding speed of 135mph. With a slight trim adjustment I would begin the flare reducing to 115 mphjust above the runway as you set up for a “four-point landing.” It was likeflying a heavier single-seat Mustang, and you brought it in pretty much thesame way you would a Mustang; you could land it on the wheels or four-point it.
If you’re not flying it tactically, you fly it right down the middlecenterline, or if you wanted to land it on one side or the other, that would befine too. There was never a problem four-pointing it at all.
As a fighter pilot in single-engine fighters, I thought the TwinMustang was a little heavy, and although it had the range as a bomber escort, Ididn’t think it could have been very effective in maneuvering with some of theextremely agile Axis fighters like the Tonys and Georges or the Fw 190s and Me109s. We used to say, “Don’t dogfight with anybody but another P-82 when youwere flying it.”
The early Twin Mustangs did not have boosted controls and were heavyand sluggish — you were really pooped out after flying it. Thankfully the latermodels did have boost. The primary flight control surfaces are conventionallyoperated from either co*ckpit. A hydraulic booster system affords boostassistance to the aileron, elevator, and rudder controls reducing the amount offorce from the pilot for their movement. The surface control boost is suppliedby three separate hydraulic systems: one providing aileron boost along with twoidentical systems (one in the rear of each fuselage) providing elevator andrudder boost. All three surface control booster systems are controlled by asingle on-off hydraulic boost switch located on the surface control switchpanel at the right side of the pilot’s co*ckpit.
As the primary test pilot on the Twin Mustang I was responsible forobtaining all the performance data and the drudgery of colleting it all. I flewall the profiles — flying it at low speeds all the way up to high speeds andgetting the fuel consumption figures. Just about everything you can do andeverything I could see about the airplane, I would report on.
I was not assigned to do tests on its weapon systems, and I recall thatresponsibility at that time was for the pilots at Eglin Air Force Base.
The Twin Mustang had six .50-caliber fixed machine guns located in thecenter wing with electric heaters, and 400 rounds per gun could be carried. AK-18 compensating gun sight was mounted on the instrument panel shroud in thepilot’s co*ckpit (left side). The Twin Mustang could carry a variety ofconventional weapons including a total of 25 underwing rockets mounted on fiveseparate rocket racks. Both 1,000- and 2,000-pound bombs could be carried aswell. So, as a weapons platform it sure seemed to be able to carry a plentifulload.
During the more than 250 hours I had in the Twin Mustang, I took it toAlaska for a cold-weather test.
It had an internal heater system, and all these things wereinstrumented so we were testing how that thing functioned in cold weather. Aseparate heating, ventilating, and defrosting system is provided in eachfuselage as heated air (obtained aft of the coolant radiator) is distributed todefroster outlets at the windshield, to a floor outlet at the pilots’ feet, andto outlets at each side of the seats. During flight the heater is normallyoperated only for anti-icing but may be used to obtain additional heat underextreme conditions. We were just getting data to see how that heating systemperformed in real cold weather. At low outside air temperatures and duringlong-range cruise operations at low powers, I found that the fuel-air mixturesmay be too cold for proper vaporization. It was important to check enginecharge temperature gauges carefully and to use engine charge heat as requiredto maintain desired mixture temperatures.
The bailout procedure in the P-82 was to reduce speed and trim theairplane to fly hands off. Disconnect radio and oxygen equipment and, if youcould remember, inhale as much oxygen as possible before disconnecting. Withsafety belts and shoulder harness disconnected, jettison the canopy and raisethe seat to the top most position. Rise to a crouched position in the seat anddive outboard toward the top wing. Thankfully I never had to test thatprocedure.
