Miller Dynasty® 200 DX AC/DC TIG/Stick Welder Flies High for Air Show Pilots

Miller Dynasty® 200 DX AC/DC TIG/Stick Welder Flies High for Air Show Pilots

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Miller's Dynasty 200 DX AC/DC TIG/Stick welder becomes a permanent fixture in the airshow's mobile repair trailer for its input power flexibility and reliable performance.

Memorial for Fallen Pilot Planned

Miller had just published a feature story on the welding and flying of aerobatic stunt pilot Jim LeRoy, Jr. when we learned of his passing on July 28, 2007 due to an accident at the Vectren Dayton Air Show. LeRoy, founder of Bulldog Airshows, was performing the “Code Name: Mary’s Lamb” show, doing what he loved: flying.

We proceed with his story in honor of LeRoy’s passion for flying. In lieu of flowers, LeRoy's friends and family are asking that contributions be directed to a scholarship fund being set up in the name of his son, 4-year-old Tommy LeRoy.

Contributions should be directed to:

Jim LeRoy, Jr. Memorial Fund

c/o Harris Bank

110 E. Irving Park Road

Roselle, IL 60172

Any questions regarding the fund should be directed to bank representative Nancy Little at (630) 980-2700.

A memorial service and celebration of LeRoy’s life will be held on Wednesday, Aug. 8 at 11:00 a.m. at the DuPage County Airport (airport identifier: DPA), 2700 International Drive, West Chicago, Illinois 60185, phone (630) 584-2211. The location will be in a hanger used for community events just southwest of the Flight Center Building. Those planning to attend the service are encouraged by the International Council of Air Shows to send a brief RSVP message to

We will keep LeRoy and his family in our thoughts and prayers.

- Terri Ann Barry, PR Manager, Miller Electric Mfg. Co.

Bulldog Airshows Takes Welding Into the Wild Blue Yonder

With a quick pull on the control stick of his modified Pitts S2s, Jim LeRoy goes from experiencing negative 7.5 to positive 9 Gs, at times pushing into his seat with a force of 1,800 lbs. Doing what he loves to do most, LeRoy executes a series of snap rolls, flips and vertical dives—all part of a precisely calculated maneuver. It’s just another day at the office for LeRoy, professional stunt pilot and owner of Bulldog Airshows.

The flying, according to LeRoy, is the easy part. Running two extreme air show businesses while traveling with his family and maintaining his planes is the hard part. Founded in 1992, Bulldog Airshows has two aircraft that travel to over 25 shows a year, thrilling spectators around the world. LeRoy also co-founded the X-Team, a supercharged stunt show that features several aircraft, turbo-charged trucks and enough pyrotechnics to make the hair on your arms stand up—definitely not your typical air show.

Flying in an aerobatic air show can be challenging. Recently, LeRoy realized the importance of being able to TIG weld “on-the-fly” or risk being grounded.

Mayday, Mayday, I Need a Welder

LeRoy, a licensed Airframe and Powerplant (A&P) mechanic with a background in Aeronautical/Aerospace engineering, never learned how to weld. Instead, he relied on his crew or local shop for welding repairs. This shortcoming became a problem during a show in Al Ain, United Arab Emirates.

During an aggressive maneuver, he heard a loud bang. “Bam! It sounded like a firecracker going off inside the plane,” recalls LeRoy. He couldn’t tell if it was the sound of his helmet hitting the side of the canopy or something structural failing in his plane. On the ground, he discovered that a vital fuselage tube snapped loose around a welded joint. It needed to be welded back into place to restore the craft’s airworthiness before he could finish the weeklong show.

The stakes were high because, for every day LeRoy couldn’t fly, he would be penalized 20 percent of his contract fee, a significant amount of money. Equally important, his reputation was on the line, as he had never missed a performance. Now he found himself in a foreign country without a welding unit or anyone qualified to TIG weld chrome-moly tubing. This time the pressure was on the ground, a place where LeRoy doesn’t like to be.

Fortunately, he found a mechanic to make the repairs that allowed him to complete the show. This close call, however, left LeRoy rattled.

“I decided that it was time I learn to weld,” says LeRoy. “I can’t afford to get caught with a broken airplane and not have the equipment or ability to fix it.”

LeRoy turned to Jim Kimball Enterprises, Inc., of Zellwood, Fla., for a course in TIG and Stick welding. The shop specializes in welding fuselages, like the Pitts Model12, from scratch using Miller welding equipment. The shop’s dedicated team had both the patience and skill to give LeRoy instruction on Stick and TIG welding.

“Surprisingly, Stick welding is actually as beneficial to me as TIG because I can weld on my transport trailer,” says LeRoy. “I really took to Stick like a duck to water. However, TIG took a lot of practice and trial and error to get the technique just right. On thick material I can lay some great beads; it’s the thin-walled tubes that I have burn-through problems with.”

Today, a Miller Dynasty® 200 DX AC/DC TIG/Stick welder is a permanent addition to LeRoy’s Air-Ride trailer, a mobile shop that houses his aircraft, tools and spare parts.

LeRoy selected the Dynasty 200 DX, which has up to 200 amps of welding power, because it incorporates Miller’s exclusive Auto-line™ power management technology. LeRoy can plug this unit into any primary power around the world, from 120 through 460 VAC, single- or three-phase, 50 or 60 Hz. The Dynasty maintains a steady welding output even if the primary power fluctuates, such as when running off a portable generator LeRoy uses while traveling.

“Auto-Line technology really sets the Dynasty 200 DX apart from any competitive TIG/Stick inverters out there,” says Brent Williams, business unit manager, Miller Electric Mfg. Co. “Operators will never experience a fluctuation in the welding arc so long as the primary power remains within a 120 to 460V range. With this type of primary power and weld process flexibility, the Dynasty 200 DX meets LeRoy’s need to weld both in the shop and at the airfield—wherever in the world it may be.”

The Dynasty 200 DX also features a built-in pulser, sequence controls and trigger functions that can be operated from a fingertip control. [Contractor Kit.jpg] Pulsed TIG increases arc stability, while the sequence controls and trigger functions give LeRoy more control over heat input; combined, they help prevent burn-through and warping on thin material. Best of all, the Dynasty 200 DX weighs only 45 lbs., making it light and portable to meet his travel needs.

Planning for Performance

Stunt pilots are known for aggressive aerobatic flying, which results in a number of physical stresses that the plane and pilot must cope with in the air and on the ground. Jim LeRoy personally had a hand in many of the advanced modifications along with routine maintenance and repair of his planes.

Bulldog II is LeRoy’s primary plane for U.S. shows. It started out as a back-up plane built from spare parts for Bulldog I, which now operates internationally.

“We soon realized that if we could get a fuselage, we would have everything we for another airplane,” recalls LeRoy. “We decided to make Bulldog II into a super refined version of Bulldog I with ad ded performance.”

To give the Bulldog II the horsepower it needs to perform extreme aerobatic maneuvers, LeRoy uses a Lycoming 540, six-cylinder, air-cooled direct drive engine which has been highly modified by Lycon Aircraft Engines. The new engine puts out over 400 HP, a massive improvement considering the stock motor of the same class is only capable of 260 HP. Bulldog II’s top sustained speed is 200 mph but LeRoy reaches speeds over 240 mph during his performance.

LeRoy had Jim Kimball Enterprises modify the fuselage of Bulldog II to strengthen key areas and add aerodynamic advantages, while attempting to keep the weight down. “Welding 4130 chrome-moly tubing into various configurations added crucial strength to the fuselage. From an engineering standpoint, you need to understand how the frame will transfer the load to all the other components.”

Stress on such a light aircraft causes the frame to flex quite a bit. LeRoy inspects Bulldog II for structural integrity every weekend before a show. The harder the flight, the more flex the fuselage experiences. ”You’re going to have cracking due to cycle fatigue, there’s just no way around it on an airplane that’s flown hard and aggressively,” says LeRoy. “You have to maintain a diligent inspection program and be ready for the repair when something does break.”

LeRoy and his crew remove covers and access panels to inspect various structures and weld clusters, occasionally using a small TV camera hooked up to a monitor to get into hard-to-see places. Structurally solid tubes and joints are taken seriously for safety of the flight. The aircraft’s wings are precisely designed for removal with relative ease during transport and inspection. If something comes apart hard or goes together hard, the crew knows something got bent, and it’s time to investigate. With the inspections and safety precautions complete, LeRoy is able to focus on what he gets paid for: the love of flying.


The Evolution of the Air Show

Jim LeRoy is just one of a handful of pilots who successfully juggle their business responsibilities and still make a living doing what they love: flying. It’s a challenge, as air shows in general have had a bumpy ride over the last 20 years. A lot of the midsized shows have gone out of business due to a lack of attendance and interest. Although they started the airshow business back in the barnstorming years, civilian airshow pilots have lost popularity amongst the airshow audience. A saturation of copycat performers offering similar routines has made for dull entertainment verses the unique spectacle that they once used to provide. Modern airshow perfomers, according to LeRoy, need to adapt and offer something fresh or face extinction.

“Imagine if you were going to the circus and all they had was one tight rope walker after another, after another… you’d get bored with it rather quickly,” says LeRoy. “A solo performer doing a solo performance at an air show is no longer that special. We’ve got to step it up, work together and deliver a better, more spectacular show.”

LeRoy shared this vision with another stunt pilot, Jim Franklin, and together they co-found the X-Team in 2002. The X-Team is a group of eight top-notch performers that banded together to deliver a truly unique show featuring a Hollywood-style production with over-the-top theatrics. Together, the X-Team strives to do for the air show business what Cirque du Soleil has done for the circus: pump some energy back into the business.

Part of a brilliant marketing strategy, the X-Team found a way to involve fans beyond the airfield and keep them coming back for more. All of the X-Team’s shows are based on an online science-fiction story that fans can follow. Each show is a chapter in this futuristic story where technologically advanced machines have taken over the world and a group of freedom fighters (the X-Team) use their antique aircraft to save the day. This storyline is paired with riveting music, pyrotechnics and lots of special effects to captivate the audience. “Masters of Disaster” and “Critical Mass” were the first two shows that increased the popularity of the X-Team. In 2006, they introduced the “TINSTIX of DYNAMITE” show followed by the currently popular “CODE NAME: MARY'S LAMB in 2007.”

The life of a professional stunt pilot is never boring. Challenges arise in the air and on the ground. Jim LeRoy found that the secret to success is in the planning and preparation. Learning how to weld, along with his knowledge of what to weld, reduces the chance of LeRoy letting a customer down. A lot of work went into Bulldog II, making it one of the most impressive air show planes in the world. Add this to the unstoppable energy of the X-Team and you’ve got the script for a great show.

Building Bulldog II

This jig was used to fabricate the new elevators, which are 10 percent larger and more angled than the originals. A jig ensures measurement and angle accuracy while the tubes are welded together. This process is repeated to create both the left and right elevators.


After the welding is complete, the elevators are attached to the tail to ensure accurate alignment and balance prior to painting.


Here a portion of the elevator and tail are being powder coated with a rust resistant primer.


The finished elevator and tail components.


Originally, the tail was flexing too much, leading to stress cracks in the fuselage. Aircraft mechanics at Jim Kimball Enterprises Inc. installed additional struts, making the rectangular bays of the fuselage more ridged while allowing the whole tail to be detachable. Increased strength with less flex in the frame is desired for extreme aerobatic flying.


The tail and elevator components are attached. Some additional cross members were welded in to stiffen the rear of the fuselage where the tail connects.


The main attach points for the seat seen here on the left was reinforced to manage the positive and negative G load that pilot Jim Leroy experiences during his aerobatic routines.


Upper longerons were reinforced around the main fuel tank mounts, seen here along with a 17-gallon auxiliary tank (below) used for smoke oil special effects at airshows.


The engine cowling was redesigned to accept the modified Lycoming 540, 400 HP motor. An extra engine point attachment was added to the fuselage to increase support from a four-point to a five-point attachment.



Important modifications for converting a stock Pitts into an aerobatic configuration include reinforcing wing attach-points on the upper and lower spars. A precise design allows for the wings to be easily removed for transport.


The completed fabrication is seen here with the fully skinned tail and fuselage. Traditional cloth and paint are the materials used for the skin of Bulldog II. After the final components are installed (power plant, avionics, wings, etc.), Bulldog II is ready to light up the skies.

Aircraft Specifications

Jim Leroy’s Pitts S2s

Bulldog II

- Aircraft Performance Specs -

Length: 18 feet

Wing Span: 19.5 feet

Weight: 1,250 lbs.

Power: 400 HP

Max Speed: 250 Mph

Max Cruise: 195 Mph

Fuel Capacity (cross-country configuration): 45 gal.

Fuel Capacity (airshow configuration): 22 gal.

Range: 450 miles

Roll Rate: 330 degree/sec.

Routine G Loading: +10, -9


Sources & Links

Updated: July 25, 2018
Published: April 1, 2008