Aerospace & defenseDecember 8, 2021

Re-engineering history

Unlike most other WWII aircraft, none of Romania’s IAR 80 fleet survived. Nor did most of the schematics and blueprints used to build them. But a group of engineers-turned-detectives is recreating the IAR 80 as a 3D virtual twin experience, with plans to build and fly it again.
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Avatar Tony Velocci

Aviators who have done it say nothing can compare to piloting a vintage military aircraft back into the sky following a painstaking, multiyear restoration. When it’s time for the warbird to escape the churlish restraint of gravity and playfully perform maneuvers as it did in its heyday, the spine-chilling exhilaration is unparalleled.

Grigore Leoveanu, project manager and president, IAR 80 Fly Again (Image courtesy of Grigore Leoveanu)

Yet the story of reconstructing a decades-old airplane begins and history unfolds long before it’s ready to fly again. A case in point is the IAR 80, a Romanian World War II fighter. To commemorate its historical significance and introduce a new generation to this almost forgotten aircraft, an all-volunteer group of seasoned engineers and in-training engineering students, working through the non-profit Fly Again Association, have pooled their collective talent to re-engineer, build and fly the aircraft in a two-year mission. 

“This is more than just an aircraft,” said Grigore Leoveanu, project manager and president of the IAR 80 Fly Again initiative. “It is a symbol of courage and sacrifice of Romanian pilots and represents engineering creativity. Generations of aviators grew up with this elegant aircraft in their souls and hearts, and it is our duty and honor to preserve and promote this exceptional achievement in the country’s history.”

REVIVING A GHOST

Historic, indeed. When it was introduced in 1941, the IAR 80 rivaled some of the most legendary designs of its day. Romanian workers built a total of 450, which served on the Russian front and protected vital installations in Romania until the war ended in 1945.

The low-wing, single-seat fighter featured a closed cockpit and a retractable landing gear. Powered at various times by engines ranging from 870 to 1,025 horsepower, the aircraft had a top speed of around 317 miles per hour (approximately 142 meters per second) at 13,000 feet (about 4,000 meters) with a maximum range of about 600 miles (about 965 kilometers). It bore a striking resemblance to the Hughes H-1, a record-setting racing aircraft designed and built by Howard Hughes’ Hughes Aircraft Company in 1935.

General Ion Dobran, who flew the IAR 80 in World War II. (Image courtesy of Ion Dobran)

Former Romanian Air Force pilot General Ion Dobran, who passed away in September 2021, recalled his first flight in an IAR 80 and its impressive power: “[My] first impression was of a force sticking me to the back of the [seat],” he said.

Today, the aircraft is known mostly as a ghost; not a single example of the IAR 80 exists anywhere in the world, Leoveanu said, making it a challenge to reproduce. Adding to the project’s complexity: a complete lack of original certification documents. Most of the airplane’s blueprints were lost as well. Of the 3,000 or so schematics used in the original design, only about 160 have survived the ravages of time.

Working from those drawings and historical imagery, Leoveanu and his colleagues are extrapolating from what they have to reverse-engineer what they lack, using the same methods that original equipment manufacturers now employ to develop new commercial and military aircraft.

“This is the first project of its kind to make a replica practically from nothing,” said Leoveanu, who helped restore a YAK-3U, a post-World War II aircraft used by the Soviet Air Force and some of its satellite states to train pilots. “It’s like cloning a dinosaur.”

VINTAGE PLANE, MODERN STANDARDS

To achieve that goal, the team is using a business experience platform that hosts design, modeling, simulation, collaboration and other digital software tools essential to re-creating the IAR 80 almost from scratch.

The Fly Again engineering team is about 20% of the way through the project, with a goal of replicating the IAR 80 as close to the original configuration as possible – as seen in this photorealistic 3D model – and sending it back to the skies. (Image courtesy of IAR 80 Fly Again)

Magic Engineering, a software reseller based in Brasov, Romania, helped get the project off the ground, sponsoring licenses for the platform and software in support of project team members working remotely in Europe and North America. More recently, the 3DEXPERIENCE Edu team at Dassault Systèmes became the IAR 80 team’s software sponsor, supporting the project’s commitment to use the IAR 80 reconstruction to train the next generation of aerospace engineers at Universitatea Politehnica din Bururesti.

The first stage in developing any new airplane is conceptualizing the design, including defining the aerodynamic surfaces in 3D models, based upon how it will be flown. But today’s airworthiness standards are far advanced from those in force during World War II; when the IAR 80 project is completed, it will be flight tested under EASA (European Union Aviation Safety Agency) CS-23 rules. Only then will it be permitted to perform aerobatic flight demonstrations at air shows across Europe, bearing the next tail number in the IAR 80’s sequence: 451.

Fernando Petre (Image courtesy of Fernando Petre)

“We’re not building a museum piece,” said Fernando Petre, an aerospace engineer at ALTEN Delivery Center Romania, an engineering consulting firm in Romania, and a member of the core IAR 80 project team. “Pilots are already lining up to fly it.”

Only eight retired aerospace engineers were working on the project toward the end of 2021, but Leoveanu expects that number to increase substantially in 2022. Finding enough qualified people has been the biggest challenge, he said.

“We’re looking for people who have a passion for aviation and are interested in following their heart, not just using their mind,” he said.

TRAINING THE NEXT GENERATION

To help supplement the work that project team professionals are performing, and to provide valuable experience to the next generation of engineers, students enrolled in Petre’s CAD classes at the Universitatea Politehnica din Bururesti (Bucharest) can work as interns on specific tasks under Petre’s mentorship.

“Using the digital tools that reside on the platform, we were able to advance deeply into the project, collaborate across our team, communicate easier with partners and gain good visibility to the public, attracting new partners and sponsors.”

Ion Adam, retired aeronautical engineer who oversees IAR 80 stress analysis

For example, Andreea Giurcan, who’s studying mechanical engineering and robotics, helped design a 3D model of a modular clamping system for welders who will assemble the physical IAR 80 engine frame, as well as for more complex applications. “This project has given me the opportunity to find out more about [aerospace],” she said. “I learned how to make simulations.”

ALTEN Delivery Center Romania also has provided student internships for the IAR 80 project and sponsored two computer-design (CAD) laboratories for the university’s mechanical and aerospace engineering departments. In addition, the company provides computer workstations for the 3DEXPERIENCE platform that students are learning to leverage.

“Through these internships, students are discovering this extremely valuable software that emphasizes collaborative work,” Petre said.

The IAR 80 project will prove to be invaluable for engineering students in training, Leoveanu said. “It’s a teaching opportunity whose importance would be hard to overstate, and when the airplane flies they will be able to take pride in their role in helping to make aviation history,” he said.

PIECING TOGETHER THE PAST

The Fly Again engineering team is about 20% of the way through the project, and manufacturing could begin in 2022, Petre said. Since the goal is to replicate the IAR 80 as close to the original configuration as possible, digital mockups and 3D models will be constructed for all sub-assemblies. Thus far, Fly Again has completed the Finite Elements Model for the wings, vertical stabilizer and horizontal empennage; 3D Master Geometry; mockups of the engine mount, truss-type fuselage, stabilizer and wing; and a preliminary stress calculation for the horizontal tail. Work also has started on the flight controls and for aerodynamic studies.

Many of the metal parts and materials used to construct the airplane 80 years ago, such as fasteners, are no longer produced. Engineers will substitute modern-day components, but even this presents a challenge.

“We’ll require parts in very small quantities – maybe 10 of this and 20 of that – and aviation suppliers are accustomed to fulfilling orders for thousands of pieces at a time,” Leoveanu said. “We’ll have to carefully consider availability, prices and sourcing as we refine the airplane’s design.”

Locating some major subassemblies has proven to be just as challenging, testing the team’s resourcefulness. “Lucky for us, we found a lot of well-preserved equipment in the United States’ old-airplane inventory,” Petre said.

For example, no functional engines of the kind used on the original IAR 80 still exist. Instead, the replica will be equipped with a Pratt & Whitney engine used on the World War II-era DC-3 and B-24 Liberator airplanes – courtesy of the US military, which maintains a sizable inventory of such equipment purchased in large quantities in the 1940s and 1950s. Not only does the engine come with a warranty and spare parts; it also has been certified by the FAA (Federal Aviation Administration), a huge time-saver on the road toward building a flight-worthy aircraft that meets modern safety standards.

Similarly, the reimagined IAR 80 will employ a modified landing gear used on the T-28 Trojan, a US Air Force trainer. That model comes closest to the landing gear design on the original IAR 80, is readily available and is FAA certified.

A PLATFORM-ENABLED PROJECT

“The business experience platform we’re using is the industry standard for many engineering domains, including aircraft design,” said Ion Adam, an aeronautical engineer who retired from Airbus nine years ago and now oversees stress analysis on the newly designed IAR 80. “Using the digital tools that reside on the platform, we were able to advance deeply into the project, collaborate across our team, communicate easier with partners and gain good visibility to the public, attracting new partners and sponsors.” 

Engineering students at Universitatea Politehnica din Bururesti are gaining hands-on experience with the same design, simulation and project management software used by many industries. In this view, the list of sub-assemblies shown on the left has been digitally assembled to create a full view of the IAR 80. (Image courtesy of IAR 80 Fly Again)

Without the platform’s capabilities, Petre said he can’t imagine how the project would be accomplished. Leoveanu concurs: “It would have been impossible to even dream about recreating the IAR 80,” he said.  “We don’t have a big team of aerospace professionals, but we still have to be very efficient, and the platform is making that possible.”

Both engineers also expect the digital thread enabled by the platform to be invaluable when it is time to get a national flight permit.

“It won’t be quite the same airplane as configured at the start of World War II,” Petre said. “The fuselage will look almost indistinguishable, but inside it will look a little different.”

Although it won’t be visible, the reverse-engineered IAR 80 will be better than the original, said team member Viorel Motoc, a design and structural engineer who has worked at Boeing, Bombardier and Gulfstream.

The engine will be about 20% more powerful, the horizontal stabilizer will be stronger, the aircraft will be lighter and experience less vibration in flight, the materials will be more reliable, the manufacturing methods will be vastly improved, and the calculations that go into the airplane’s overall design will be more precise, he said.                                                                           

COMPLETING THE PUZZLE

If there’s a compelling takeaway from the IAR 80 Fly Again project, it’s that preserving and restoring – or, in this case, recreating – historical aircraft is a global passion. Their pursuit is not just a labor of love but a love of aviation, coupled with an irrepressible national pride.

“This is the first project of its kind to make a replica practically from nothing. It’s like cloning a dinosaur.”

Grigore Leoveanu, project manager and president, IAR 80 Fly Again initiative

“Fans of famous warbirds thrill to the sight of P-51 Mustangs, Focke-Wulf F-190, Supermarine Spitfire and many other vintage airplanes flying today,” Adam said. “Romania’s IAR 80 was among those splendid classics at one time but is missing from the gallery. Now is the time for this victorious ‘bird to join them.”

“The end result is that the re-designed IAR 80 will be a faster, safer and more maneuverable airplane,” Motoc said.

Tony Velocci is the retired editor-in-chief of Aviation Week & Space Technology magazine.

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