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
In 1943 with a world war raging on all fronts, the Allied military planners knew that in order to gain supremacy over the Axis they needed to hit the enemy’s industrial targets deep inside of both Europe and Japan before they could concentrate on any invasion planning. The B-17 Flying Fortresses and B-24 Liberators in Europe already had the range, but fighters like the P-38 Lightning and P-47 Thunderbolt could only escort them so far before having to turn back, leaving the bombers unprotected. The P-51 Mustang had yet to come on line. The Pacific theater was much worse with no forward bases close enough to launch aircraft from to attack the Japanese mainland. A new wonder weapon, the B-29 Superfortress would soon be coming on line, giving the Allies the ability to strike Japanese homeland targets, but it would have to go it alone with no other fighter escorts because none of the current inventory had long enough legs to make the exhaustive round trip.
North American Aviation Assistant Chief Designer Edgar Schmued, famously known as the primary designer of the P-51 Mustang, was tasked once again with coming up with the required design and solution for a long-range escort. Schmued and his design team narrowed its focus to two different proposals. The first was a twin-engine, single-seat fighter supported by tricycle gear. The second proposition was a more radical design comprising two fuselages, each housing a pilot and Packard-built inline 1,860-hp Rolls-Royce Merlin engine. The twin fuselages were attached to a 400-square-foot wing housing six .50-caliber machine guns. This design became the genesis of the P-82 Twin Mustang.
When the military came calling on NAA in November of 1943 it was already planning and focusing on an inevitable and costly invasion of Japan. Gen. Hap Arnold was quoted as saying, “We need an airplane that’s 50 mph faster than any current fighter and has six hours further range and will be able to cruise with the B-29s.” A B-29 will cruise at 300 mph. The Mustang will cruise at 245. The P-82 will cruise at 280-300 mph. That was a whole bunch closer to the B-29.
But the P-82 not only had to have speed, it had to be a flying gas tank as well. With an internal fuel load of 600 gallons, plus two 310-gallon drop tanks, the Twin Mustang had a combat range of 2,700-3,300 miles depending on throttle settings. This was the airplane the Allies needed to help win the war as a large order was placed by the Army Air Forces. By the time production began and two prototypes were built, along with less than a handful of others, the war was winding down and the need for long escorts had been solved in the Pacific with the capture of nearby Japanese-held islands. A scaled-back production schedule was initiated along with an engine change.
“Because the British wanted a $6,000 royalty fee for each Rolls-Royce Merlin engine, the military thumbed their noses at that prospect and selected the 1,600-hp Allison V-1710 engines to power the later model F-82s,” Tom said. “They were somewhat reliable but were not as powerful as the Merlins.”
After the U.S. Air Force became an independent branch of the military in September of 1947, the letter P for pursuit was changed to F for fighter in June of 1948. The F-82 eventually saw heavy service in Korea, filling the gap and holding the line. The F-82 held the 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 fighters and had to pass the torch to the next generation of North American Aviation-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 patrol environment in Alaska. Fourteen F-82s — modified, winterized H model versions — were stationed there, and they had the large radar pod mounted in the center that stuck out beyond the propeller, so the propeller wouldn’t interrupt the radar signal. The interior changed as well as the pilot in the left fuselage had full controls, but the co-pilot on the right side had the responsibility of monitoring the electronics. The sad fact was, when the Air Force determined the F-82s were no longer operational, many were simply scrapped: 248 of the 272 built were scrapped, 13 were lost in Korea, five were lost stateside, and one was lost in Alaska, [which wasn’t yet a state].”
Of the first two XP-82 Twin Mustangs built by North American Aviation in 1945, only one survived the scrapper’s torch. The first airplane, 44-83886, accumulated less than 300 hours at 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, and Restoration
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, F2G Corsair, 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 P2V Neptune, C-82, B-36, and the prototype North American XP-82 Twin Mustang — to name just a few. Walter was not a pilot — more of a visionary in a sense as he unwittingly helped preserve our nation’s history while the short-sighted military considered many of these airplanes as throwaways. But the military was far from finished with the Twin Mustang.
“When Walter took possession of the XP-82, the military kept the propellers and engines and left him with the remains,” Tom said. “He unbolted the outboard wings and cut the center section apart with a 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 the airplane back to test it to destruction because a bunch of these airplanes are going to Korea.’ They traded him an F-84 for the right-hand fuselage and center section, and the outboard wings and the tail.”
Tom first met Walter in the early 1990s when he was called to the farm to perform an IRS appraisal on one of Walter’s aircraft. While roaming the grounds Tom at first thought he spied a P-51 Mustang, until he did a double take and realized it was an Allison-powered F-82E Twin Mustang. At the time Walter had not told Tom that what he had was the second-built XP-82 along with all the parts that had come back from NACA after they had crushed the right-side wings and tail.
“I first thought all he had was the left fuselage. I knew that if I was ever going to realize this dream of rebuilding and flying a Twin Mustang, I would need to find the ultra-rare left-turning Merlin engine and propellers and lots of other missing parts and pieces,” Tom said. “That’s when I began to scour the Earth for anything and everything P-82/F-82 related.”
With most of the XP-82 treasure hunt complete in Ohio, Tom trucked everything to his shop in Douglas, Georgia, and began to inventory and document each and every item. He also contacted all of those individuals with assorted P-82/F-82 parts around the country and obtained many of the needed parts for this massive project. With such a gigantic undertaking Tom also sought out airplane craftsmen and women to hire to either repair, rebuild, or re-create all the hundreds of thousands of parts needed to make the XP-82 not only flyable, but one that was a real showstopper. This included replicating the grease pencil graffiti found inside of one of the fuselages, which included the likes of, “Henry will have the tickets for the theater tomorrow” or “426AD4-6 rivet goes here” with an arrow pointing where one shift left a note for the following shift. From tackling both fuselages first to the horizontal stabilizer and working his way forward, Tom was laser focused in his approach. If he didn’t have a particular piece or part, there were times Tom would call upon fellow F-82 restorer Pat Harker to see if he had already overcome the obstacle or had the parts Tom needed.
“Pat Harker has been incredibly helpful on this project,” Tom said. “I’ve visited his project several times, and his workmanship is nothing short of magnificent. I have taken countless photos and measurements, and he has helped us immensely with 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 our projects as the original Aero Products propellers were impossible to locate.”
Tom began quietly contacting individuals with P-82/F-82 parts and paid a down payment for a “right of first refusal,” telling no one of what he had discovered in Ohio. Sourcing parts, Tom found a variety of individuals who had salvaged Twin Mustang parts from an Alaska scrapyard: three fuselages and three chunks of center section. There was another fuselage located in California, but the owner would only trade for P-51J parts — an NAA airplane rarer than the XP-82 as only two were built. (Tom was able to locate a J model windscreen on the Soplata farm that Walter had bought years early, and he traded it for an F-82 left-hand fuselage that had all the dual controls he needed.) There was a woman in Florida who had a P-82 canopy and countless others around the country with various bits and pieces. Parts aside, Tom’s main concern was finding the specially made left-hand turning Merlin engine. Without it, Tom would have had to install two right-hand turning engines on the XP-82.
Locating that engine was futile at best. On the verge of giving up, Tom located a left-hand core, but the owner was reluctant to even part with that. Tom’s dream was just about to vaporize before his eyes on having a counter-rotating XP-82 and putting on two right-hand turners when out of the blue his phone rang.
“It was Mike Nixon, owner of Vintage V12s in California, calling me out of breath and asking if I made an offer on the left-hand engine core yet,” Tom said. “I told him I hadn’t, and he said good, don’t because he had just found a brand new V-1650-23 still in the box in Mexico City. I didn’t even ask the price and told him I would buy it.”
To properly describe and document the restoration of XP-82 83887 and what Tom and his team have accomplished in the last 10 years would take volumes to accomplish. But what was most evident speaking with him about this project was the fact that Tom Reilly does not live for shooting another rivet tomorrow, it’s to discover a problem that comes up and then find a solution to fix it. Tom likes to take projects that people say can’t be done and restore them to flyable, award-winning restorations.
With tongue in cheek, Tom says he could have finished the XP-82 much earlier but he only worked on it half days — 12 hours per day.
“I still kick myself for taking that one Christmas Day off a few years ago,” Tom said. “I could be farther ahead if I had only worked on this airplane. Seeing the light at the end of the tunnel and realizing it’s not a train is good feeling. But my main goal, before I pass on, is to teach as many young kids the skills needed to not only obtain their A&P ticket, but more importantly help keep these vintage warbirds, like the XP-82, flying for future generations to enjoy and cherish. Someone has to be the caretakers of them. As we are only temporary 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, and it accelerated so fast that we found we were flying,” Tom said. “It accelerated so fast it sort of surprised us. I was standing on the side of the runway at the 2,000-foot mark, and he was only supposed to get a little bit of air under the wings and then put it back down again. It accelerated so rapidly it popped off the ground. Ray Fowler, the test pilot, made the right decision to go around, and he flew for about five minutes and it flew hands off, perfectly in trim, and it was definitely the highlight of my life.”
On January 28, 2019, the official first flights and test began. The first five flights were intentionally made gear-down flights. With everything looking good, it was time for Tom to climb in the right cockpit.
“We had a couple minor little squawks, which was expected, and I got in the right-hand seat on the fifth flight with the FAA’s blessing,” Tom said. “I’ve flown Mustangs, but I never expected to feel the power that this thing had. It has 1,860 hp per engine compared to 1,500 hp for the Mustang, and it’s 3,700 approximate horsepower and only about half again the weight of a regular Mustang. So it accelerated dramatically fast and it climbed like crazy, so it was a thrill. Sitting in the airplane, the anticipation overwhelmed me with over 10 and a half years of labor, 207,000 man and woman hours to put this airplane together. The exhilaration of how fast it accelerated, and then climbed out at about a 30-degree angle without even slowing down at all, it was just exciting that I can’t explain. I am overjoyed with how well it flies and can’t wait to bring it in to EAA Oshkosh 2019.”
Reflections of a P-82 Twin Mustang Test Pilot
Col. Bud Anderson (retired U.S. Air Force), 357th Fighter Group ace and pilot of P-51 Mustang Old Crow with more than 116 combat missions during World War II (without receiving a single hit from enemy fire), returned home just before the war in Europe came to 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 test on the North American P-82E Twin Mustang. I don’t recall if I flew the XP-82 while assigned to Wright, but I remember I also had P-82B time as well.
The early Twin Mustangs had Merlin engines installed, but the later models like the E were powered by two 12-cylinder, liquid-cooled, V-type Allison engines equipped with speed density carburetors and water-injection systems. The cockpit was somewhat similar yet completely laid out differently. The landing gear handle was like the other one and in a similar location. And the flaps handle was generally in the same location as the other ones. They were 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 cockpit and looking right and seeing this other mass sitting across from you and you realize you’re flying formation with another Mustang that’s attached to you. The Twin Mustang’s wingspan is 51 feet, 3 inches and the fuselage length is 39 feet with the gross weight at 20,450 pounds. In comparison, a standard D model Mustang has a 37-foot wingspan and a length 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 more horsepower than a D model I flew in the war. Takeoff procedure was to hold the stick back to neutral to lock the tail wheel.
With the Mustangs’ long noses you still have to taxi in an S-turn. And then you have this other airplane S-turning with you, which you eventually just deal with. I was always trying not to use too much brake or none at all. The guy 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 piloted on the left side only, with the radar operator on the right.
When all your systems checked out and were in the green you began the takeoff run by advancing throttles to 72 inches. With flaps up we lifted off around 110 mph, and with 20 degrees of flaps our mains lifted at 100 mph. It would climb out pretty good. It was heavier than a single-seat Mustang so it probably dumbed down the performance characteristics to that.
Single-engine operation was okay — just hold the airplane straight with rudder and feather the prop on the failing engine. Adjust the power settings on the good engine and trim the airplane as required. No adverse effects at all as the other engine had plenty of 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 below 200 mph. Full flaps (40 degrees) on final maintaining a gliding speed of 135 mph. With a slight trim adjustment I would begin the flare reducing to 115 mph just above the runway as you set up for a “four-point landing.” It was like flying a heavier single-seat Mustang, and you brought it in pretty much the same 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 middle centerline, or if you wanted to land it on one side or the other, that would be fine too. There was never a problem four-pointing it at all.
As a fighter pilot in single-engine fighters, I thought the Twin Mustang was a little heavy, and although it had the range as a bomber escort, I didn’t think it could have been very effective in maneuvering with some of the extremely agile Axis fighters like the Tonys and Georges or the Fw 190s and Me 109s. We used to say, “Don’t dogfight with anybody but another P-82 when you were flying it.”
The early Twin Mustangs did not have boosted controls and were heavy and sluggish — you were really pooped out after flying it. Thankfully the later models did have boost. The primary flight control surfaces are conventionally operated from either cockpit. A hydraulic booster system affords boost assistance to the aileron, elevator, and rudder controls reducing the amount of force from the pilot for their movement. The surface control boost is supplied by three separate hydraulic systems: one providing aileron boost along with two identical systems (one in the rear of each fuselage) providing elevator and rudder boost. All three surface control booster systems are controlled by a single on-off hydraulic boost switch located on the surface control switch panel at the right side of the pilot’s cockpit.
As the primary test pilot on the Twin Mustang I was responsible for obtaining all the performance data and the drudgery of colleting it all. I flew all the profiles — flying it at low speeds all the way up to high speeds and getting the fuel consumption figures. Just about everything you can do and everything I could see about the airplane, I would report on.
I was not assigned to do tests on its weapon systems, and I recall that responsibility at that time was for the pilots at Eglin Air Force Base.
The Twin Mustang had six .50-caliber fixed machine guns located in the center wing with electric heaters, and 400 rounds per gun could be carried. A K-18 compensating gun sight was mounted on the instrument panel shroud in the pilot’s cockpit (left side). The Twin Mustang could carry a variety of conventional weapons including a total of 25 underwing rockets mounted on five separate rocket racks. Both 1,000- and 2,000-pound bombs could be carried as well. So, as a weapons platform it sure seemed to be able to carry a plentiful load.
During the more than 250 hours I had in the Twin Mustang, I took it to Alaska for a cold-weather test.
It had an internal heater system, and all these things were instrumented so we were testing how that thing functioned in cold weather. A separate heating, ventilating, and defrosting system is provided in each fuselage as heated air (obtained aft of the coolant radiator) is distributed to defroster outlets at the windshield, to a floor outlet at the pilots’ feet, and to outlets at each side of the seats. During flight the heater is normally operated only for anti-icing but may be used to obtain additional heat under extreme conditions. We were just getting data to see how that heating system performed in real cold weather. At low outside air temperatures and during long-range cruise operations at low powers, I found that the fuel-air mixtures may be too cold for proper vaporization. It was important to check engine charge temperature gauges carefully and to use engine charge heat as required to maintain desired mixture temperatures.
The bailout procedure in the P-82 was to reduce speed and trim the airplane to fly hands off. Disconnect radio and oxygen equipment and, if you could remember, inhale as much oxygen as possible before disconnecting. With safety belts and shoulder harness disconnected, jettison the canopy and raise the seat to the top most position. Rise to a crouched position in the seat and dive outboard toward the top wing. Thankfully I never had to test that procedure.