Plant tour: Aernnova Composites, Toledo and Illescas, Spain

Aernnova Aerospace (Álava, Spain) is a leading Tier 1 aerostructures supplier with 5,442 employees in 16 locations across eight countries supporting 30 different aircraft programs. In addition to its engineering, services and metallic components businesses, Aernnova Composites is a key part of the group’s integrated aerostructures capability and comprises six plants with 1,343 employees in Spain, Portugal and the U.K., supplying Airbus and Airbus Helicopters, Boeing, Embraer, Dassault, General Dynamics and others. 

Aernnova is a company committed to sustainability, technological development and digitization, says Dr. Miguel Castillo, vice president of technology development for Aernnova, noting:  “We go from concept, design, prototyping, testing and certification to production.” The industry’s respect for this full capability and decades of expertise can be seen in contracts awarded by Heart Aerospace to co-design the airframe of the ES-19 electric aircraft, and by HondaJet to design and build flaps, ailerons and spoilers for the Echelon HA-480. Aernnova is currently working with Boom Supersonic to design and develop the composite wing for Overture, as well as with air mobility company Lilium, developing the composite wing and nacelles for the Lilium Jet. “Instead of rotors, this aircraft uses vectored thrust from 30 electric engines,” explains Enrique Sanchez, director of composites manufacturing engineering for the Aernnova plants in Spain. “We are developing the articulated nacelles that enable this ducted fan propulsion.”

Aernnova has also developed a strategic partnership with Embraer, acquiring the Brazilian OEM’s two facilities in Evora, Portugal — one for metallics and one for composites — and is increasing production to support current and future single-aisle aircraft. It also acquired Hamble Aerostructures in Southampton, U.K. from GE Aerospace. With significant composites capability, this facility produces the large fixed trailing edge for the Airbus A350 wing, comprising more than 3,000 components.

Of the remaining four composites sites in Spain, the Orense and Álava plants in the north are dedicated mostly to parts made using hand layup (HLU) processes. CW’s tour focused on the ICSA facility in Toledo, well-known for its serial production using resin transfer molding (RTM), and Aernnova Illescas, which uses automated tape laying (ATL) and fiber placement (AFP) to produce the carbon fiber-reinforced polymer (CFRP) leading edge (LE) and other components for the Airbus A350 horizontal tail plane (HTP). The latter also serves as Aernnova Composites’ headquarters and is located adjacent to the Airbus Illescas composites plant outside of Madrid.

R&D, thermoplastic composites, digitization

R&D and innovation are part of Aernnova’s DNA, says Castillo. Notably, Aernnova is a founding member of the Clean Sky/Clean Aviation program, and also participates in regional and customer-focused R&D projects. This has enabled Aernnova to mature a wide range of composite technologies and manufacturing to demonstration/high technology readiness levels (TRL, see sidebar, “Aernnova Composites, leader in composites R&D”).

These range from high temperature-resistant composites in the SuCoHS project to thermoplastic composite (TPC) wingbox covers and fuselage components in Clean Sky 2 projects to the 2023 JEC Innovation Award finalist all-CFRP railcar with OEM Talgo saving 25% weight and reaching TRL 6/7. Regarding TPC development, Castillo notes this started with stamp forming via work with the composites R&D center FIDAMC (Getafe, Spain). “But now we want to bring that in-house and industrialize it,” says Castillo. “We also produced parts for the Clean Sky 2 MFFD and ARE projects and have worked with Cetma’s [Brindisi, Italy] technologies for continuous compression molding [CCM] and induction welding. We will mature a range of these technologies to TRL 6 by the end of 2025 for elementary parts, and then continue to mature our welding capabilities with partners.”

Another large area of work is RTM, including patented designs for multi-flange fuselage frames and CFRP struts with an integrated metallic insert for attachment. “The one-shot wingbox skin we made with Airbus in the APOLO project,” says Castillo, “was similar to the 7-meter IIAMS demonstrator by MTorres, but shorter, at 3 meters.” Other RTM achievements include:

• A 1-meter-diameter air intake for a business jet using a one-shot process.
• A 7-meter flap for the Airbus Wing of Tomorrow program (see R&D sidebar).
• A winglet for a Clean Sky 2 program using RTM with foam core and resin infusion for the leading edge.
• Modular designed RTM tools with partner Aitiip in the HERON project that facilitate innovative heating and demolding, made with a high-deposition hybrid additive layer manufacturing (ALM) process.
• Integrated “one-shot” structures for the RACER compound helicopter’s horizontal and vertical stabilizers.

Aernnova also completed the ATEA-AERO project to develop a new generation landing gear door for next generation conventional aircraft. “This is a high-curvature part where drape-formed spars are integrated as a single part with the skin in an RTM process,” says Castillo.

He notes Aernnova is in the third year of a digitalization program called Zero Latency. “We are changing our enterprise systems and connecting these to production data, but it is more than just 4.0. It will change the whole way we work and include AI support. More than 80% of our operations will be covered this year.” Aernnova is also advancing robotics for improved assembly processes, including more flexible systems that are able to handle a wide variety of parts for more resilient and adaptable production lines.

ICSA tour

Built in 1991, Internacional de Composites S.A. (ICSA) has more than 30 years of experience in composites production and was acquired by Aernnova in 2003. Our tour is led by Sanchez and Carlos Torollo, engineering manager for ICSA. We enter a lobby filled with examples of production parts including empennage fairings for the Airbus A380, A350 and A320, and the A350 HTP LE as well as the RTM structural grids for the A350 passenger (pax) door which are made in this plant. We walk through a door to where a single, large freezer on the right stores rolls of prepreg and kits of cut prepreg plies. On the left is a material testing lab. “We test incoming prepreg and can do chemical and mechanical testing as needed to support programs,” says Torollo.

He notes the production floor flow is like a “C”. It starts with materials receiving, cutting and hand layup at the entry where we are, and then moves through machining, paint, assembly and nondestructive testing (NDT)/inspection in the middle before curving back to the right for RTM production.

Cleanroom and cure

We enter the cleanroom, where two automated cutters from Lectra (Paris, France) are used to prepare prepreg kits. Laser projectors in this HLU area are supplied by Virtek (Waterloo, Ont., Canada) or SL Laser (Traunreut, Germany).“We are the single source for the A320 elevator composite parts, which are very high-rate HLU components,” says Torollo.

Fixed HLU stations are mixed with “pop-up” stations, moved as required for ramps/changes in production rates. A vacuum table along the wall is used for compacting layups. We see an A350 HTP fairing leading edge extension (LEX) in progress as well as rounded, triangular LE ribs which are vacuum bagged on small tools, ready for cure, as is a layup on a larger metal tool for the A220 auxiliary power unit (APU) door.

Quite a bit of production uses reusable bags, says Sanchez, such as parts for the NH90 helicopter. Aernnova also makes the cockpit dashboard panel for the Airbus Helicopters H160. We see A320 elevators in progress, for which ICSA makes more than 3,000 skins/year. We also see honeycomb-cored components for the A330 elevators, and a Kuzan K-30 laser projection system on wheels, which can be used to aid HLU where needed.

We exit the cleanroom into a curing area with three autoclaves supplied by TEICE (Spain), IROP (Italy) and Maschinenbau Scholz (Coesfeld, Germany) — 12 × 3.5 meters, 14 × 4 meters and 3 × 1.8 meters in diameter — and a 12 × 3.5 × 3-meter oven with an adjacent room for tool storage, demolding and tool cleaning.

Main production hall

From the curing area, we walk into the main production hall which stretches the length of the building. The next area comprises three NDT cells. One is an ultrasound testing (UT) cell on rails with dual water squirters that uses through-transmission (TTU) for larger, flat parts and sandwich parts. Just beyond are several stations where technicians perform hand UT scans of areas highlighted for further inspection.

The next NDT cell is a Tecnitest (Madrid, Spain) immersion tank that can perform single-side and TTU C-scans. The third cell by Tecnatom (Madrid) is the newest, featuring a gantry on rails. It can adapt in the X-axis (rails), Y-axis (toward or away from the part) and Z-axis (height). It is also used for sandwich structures.

As we walk through this area, we see completed skins for the A320 and A330 elevators, featuring a blue film containing lightning strike protection (LSP).  In an adjacent assembly area, technicians are attaching metal anti-erosion plates to an A350 HTP LE. We also see work on A320 elevators, and a typical SQCDP (safety, quality, cost, deliveries, persons) station for tracking and reviewing key production indicators (KPIs). “These stations share statistical process control data and other relevant production and quality indicators with the production floor in all our factories,” notes Sanchez. We leave the main production hall and enter the RTM production area.

RTM production

The first room is for kitting plies, filled with a Lectra cutter and numerous racks with stacked kits, managed by a single technician. We then enter a large cleanroom with a layup area to our left. Here, a technician has a workstation dashboard screen suspended in his cell. He speaks to the system as he completes each ply, and it checks it off in the workflow software.

Just beyond these layup areas is a large hot drape forming (HDF) machine made by Serra, a sister Aernnova company in Barcelona and Romania. Layups are heated to 90°C for 3 hours to melt the binder and compact them into a shaped preform that will be placed into an RTM mold set. The machine uses a single HDF top unit — equipped with infrared lamps for heating and forced air for cooling — with two tables for layups. While one is in the HDF processing preforms, the other is being loaded, for faster throughput. There are also two small Multitherm HDF tables from Elkom (Postfach, Germany).

“We then assemble these preforms like puzzle pieces into the RTM tools to  enable larger, integrated structures,” says Sanchez. To our right are twin vertical storage systems by Hänel Lean Life (Bad Friedrichshall, Germany) used for the various production programs’ preforming tools.

Toolroom, injection, demold and NDI

We turn right into the toolroom. Here, numerous large, self-heated steel RTM molds — wrapped in thermal insulation blankets to hold heat inside — await injection/cure cycle or have just finished and will move next to demolding. “We have two strategies for RTM production here,” says Sanchez. “The first are these self-heated matched tools. After we place the preforms and tooling inserts inside, we close and clamp top and bottom tools and connect them to injection units. The tools heat up to 120°C, resin is injected, cured under vacuum and pressure, and then the tools ramp down/cool before they are disconnected and moved to the demolding area. Some of these are heated using electrical resistance and some use heated oil. Our second approach is to use hot plate presses which heat tools by conduction from the platens.”

There are two injection/cure stations for the self-heated tools used for producing the inner structural grids that will be mated with prepreg skins at Aeronnova Illescas for the A350 pax doors and two stations for the A350 HTP LE. In the left rear corner, we watch a technician assemble a multipiece tool at a station for the A350 HTP trailing edge ribs made using a hot platen press.

“We make the A350 HTP LE in one shot, integrating the skin with ribs,” says Sanchez. “One big challenge was to maintain temperature of such massive molds at ±5°C, and we changed our control system strategy to achieve this. We deliver eight sections per plane.” Finished sets are shipped to Airbus Getafe for assembly of the HTP, which resembles a mini wing set with a 19-meter span. Airbus has said A350 production will increase from 6 aircraft/month in 2023 to 10 aircraft/month in 2026. 

We exit the cure room into the demolding and NDI area. There is a robot trimming cell for deburring the edges of dry preforms. We see a base and top for the RTM tool used to produce the A350 pax door inner structure. An overhead crane is used to lift the mold top from the base. “This is a very controlled process in order to remove the part without any damage,” notes Torollo. The base of the two-part tool for the A350 HTP LE is also here, and we can see the slots where rib preforms are placed but also the whole piece removed from it as an integrated structure. The resin flash will be trimmed off and then it will undergo final quality control inspection.

Aernnova Illescas tour

For this second tour, Enrique Sanchez is again our guide, aided by Jorge Garcia Martinez, head of manufacturing engineering for the Aernnova Illescas site, which has 300 employees on the production floor, 400 total with white collar included. Signs throughout the engineering offices confirm that diversification is an ongoing effort, but Martinez says it is still challenging to hire women technicians here. Still, two of the five C-suite directors for this site and 26% of the overall Aernnova Illescas workforce are women.

This plant was built initially for production of the composite components and assemblies for the A350 HTP. “We won this through a competitive process with other manufacturers,” explains Sanchez. “We made the design for the product, the tooling, the process and the production facility to support the production rate needed. We started prototype activities in 2010 and then fitted the line with automation. We inaugurated the plant in 2011, the same year as Airbus Illescas next door.”

Other parts in production here include the A350 #2 and #4 pax doors. “The #1 and #3 doors are made by Airbus Helicopters in Donauwörth, Germany,” says Sanchez. “We make the outer prepreg skin here and then integrate the RTM inner structure from ICSA along with other components in one specific assembly cell.” Finished doors are sent to Donauwörth for attaching door mechanisms.

Aernnova Illescas also makes the upper spar for the engine pylons on the A350-1000 and its main landing gear bay (MLGB) bulkhead which separates the unpressurized storage area for the landing gear wheels from the pressurized cargo hold. This part is sent to Airbus Atlantic in Rochefort, France, for further assembly. “We’re also developing the 4.5 × 4-meter cargo door for the A350 freighter,” says Martinez. “The skin will be made by Airbus Illescas, and we will produce the internal structure, which comprises more than 500 parts including 12 frames plus stiffeners, pins and clips. We are starting to make the tooling for this now.”

“We also make the Boeing 787 aft pressure bulkhead [APB],” says Martinez. “The shape is complex, demands a high level of quality and we had to demonstrate the ability to ramp to rate 14 in just 3 months. But we delivered on-quality and on-time to the 787 assembly line in Charleston, with the first part perfect — drop-in ready with no issues. The program VP there had all the production workers sign a banner thanking us for such a good job. We still have that banner on our production floor.”

“For the A220, we make the vertical stabilizer skins and spars which are then assembled at Leonardo’s Foggia plant,” he continues. “We also make the A220 center wingbox, which is assembled in Aernnova’s Berantevilla, Alava, plant using a completely robotic process. We also make the wing spars for the Dassault Falcon 10X; Dassault makes the skins and assembles the all-CFRP wings.”

As discussed above, Aernnova is relied on not just for structural engineering but also manufacturing engineering. “We developed the industrialized production for the A350 elevator and rudder, but then this became part of a transfer to Airbus China,” says Sanchez. “The rudder and elevators were industrialized here and then transferred completely to be produced at Harbin.”

ATL versus AFP

The Illescas facility tour begins in its 14,000-square-meter cleanroom. There are not many workers in this highly automated production area. ATL and AFP machines fill the room to the left and right of us and also straight ahead, across the main aisle that splits the room into two sections. To our left, beyond the nearest ATL machine, are two large Serra HDF machines.

“We have six ATL machines, all made by MTorres [Torres de Elorz, Spain], but each is specialized for production of different parts,” notes Martinez. “Three lay up onto flat tables, producing blanks that are then shaped in the HDF machines, and three are ATL cells that lay onto slightly curved curing tools. We also have monotape machines that load one roll of 300 meters and multitape machines that load two or four 150-meter rolls at the same time.”

He explains differences between ATL and AFP: “ATL systems can make any kind of layup pattern but are limited to shallow curvatures. You need to know about ATL in order to use it efficiently. AFP is very different, always cutting at a 90-degree angle, which results in steps at the edges instead of an angled line. So, this requires a special laminate design, and AFP systems can handle very complex geometry, but they require more maintenance.” Regarding speed, Martinez adds that the early AFP systems were slow, but now AFP has become a very fast process.

The ATL to our left is a gantry system on rails laying onto a curved cure tool. That tool starts in an HLU station just beyond this ATL cell, where a ply of glass fiber prepreg with copper mesh for LSP is applied. There are two tall towers with Virtek laser projectors. The tool is then moved to the ATL cell for the CFRP prepreg tape layup. It then returns to the HLU station for a final ply of glass fiber prepreg that serves as an isolation layer to prevent galvanic corrosion with aluminum fittings. This ply also helps to prevent flacking — delamination that occurs on the back side of holes when drilling the finished part. Next, precured stringers will be located onto this skin and applied with adhesive. The assembly is then vacuum bagged and cured in the autoclave. We also see HLU of splice straps used to join fuselage sections for the A350. These are delivered to Premium Aerotec Group in Augsburg, Germany. Four straps are made on each curved tool.

To our right, two ATL systems, across the aisle from each other, fill out that end of the cleanroom. They are laying blanks for stringers and stiffeners onto 35-meter-long flat tables. “All ATL machines that lay on flat tables have a TorresLayup head to lay tape and a TorresPanex head to cut the blanks,” explains Sanchez. “We make several parts at the same time and then cut the blanks to be formed in the HDF machine. The laying and cutting heads can cross so that we’re running both at the same time —laying first at the beginning of the table, and then swapping to lay at the end of the table. We never stop the ATL head — the goal is to keep it laying as much as possible.”

We walk to the main aisle in the cleanroom and turn right. Beyond the two large ATL flat table cells is a large prepreg freezer. There is also a cutting room with a Lectra automated cutter and a machine for cutting noodles used to fill the triangular hole between T-stringers and skins. This hole results when two “L” stringer pieces are butted back-to-back to form the “T” — but this leaves an area between the skin and the L’s that needs to be filled. This is standard procedure globally in CFRP skin-stringer production — although every facility has a different approach to making the noodles.

“We make ATL laminates and cut triangular sections for the noodles,” says Martinez. “We then locate these as we mate the stringers to the skin. Traditionally, we made fillers by hand-rolling prepreg into long snakes and then HDF formed them into noodles. But now we have developed a specific machine for cutting the prepreg into shape.” The cut plies are manually removed from the Lectra cutter. “We investigated automation, but the business case wasn’t there,” he explains.

We exit the cutting room and proceed back through the large cleanroom, past a team vacuum bagging a finished layup. Traditional bagging film is used, instead of reusable vacuum bags, explains Martinez, “because there are a lot of pleats needed and the reusable bags are too expensive. We investigated it, but again couldn’t make the business case. However, we do use reusable bags for the 787 APB.” We pass ATL #5 on our right. It is much smaller, dedicated to ribs for the HTP LE. “We didn’t need such a big machine for these parts and so were able to use a more cost-effective cell.”

HDF for stringers, assembling preforms for curing

Across from ATL #5, we stop to look at tools that will go into the HDF machine on our left. They feature male tooling inserts and are loaded with eight blanks that will be preformed into L’s which will later be combined to make four T-stringers. The vacuum bagged blanks on the tool are placed in the HDF machine and heated to 60°C, after which vacuum is applied to shape the blanks while the prepreg remains uncured. “We move the resulting preforms to a curing tool to form the final geometry,” says Martinez. “Preforming is just to create the shape to locate the layups on the curing tools. You would get wrinkles if you put flat blanks directly onto tooling inserts in the curing tools.”

“We make these stringers net shape — no trimming,” he continues. “We used to trim, but we completed an internal project to improve this. We had to demonstrate that the net-shape product was the same quality, including making tests and micrographs to show cross-sections and properties. We have also developed an alternative process where, instead of HDF, we use a press, to produce the spars for the Dassault F10X wings.”

As we continue to move through the cleanroom, Sanchez explains there are three main processes here. The first is co-curing — uncured stiffeners are mated to an uncured skin and autoclave cured together. The second is co-bonding where precured stiffeners are mated to an uncured skin with adhesive and then autoclave cured — this is used in the HTP skins. The third process is secondary bonding, where precured HTP ribs, for example, are bonded to a cured structure using adhesive and cured in an autoclave.

In the left rear corner from where we entered the cleanroom is an area for preparing A350 HTP components for co-bonding. “We don’t need tooling for this bonding of stiffeners to ribs because the dimensions are already set,” notes Martinez. “There is also no shimming.”

In this same area, a turning rack locates stringers into a curved jig and then flips this to place them onto the skin for the A220 center wingbox skins. The assembly is then bagged and autoclave cured.

AFP for 787 APB, autoclaves

We walk across the aisle to a large AFP machine in the right rear corner of the cleanroom, passing large tools for the Boeing 787 APB. “In this AFP cell, we have two areas in the bed for two of the APB tools,” says Sanchez. “We lay on one while we inspect the other and vice versa. The cell has an automated head changer to swap the head loaded with 16 spools of 1/2-inch-wide tape with the head carrying eight spools of 1/8-inch-wide tape. Both are needed to complete the layup.”

We then walk back to the central aisle and exit the cleanroom into the autoclave area. Three Olmar (Gijón, Spain) autoclaves measure 14 × 5 meters, 13 × 5 meters and 13 × 5.5 meters in diameter. “We can cure every product we make in all of these,” says Martinez. In front of each autoclave is a double-length of rail to fit two rack carts for faster changeout — one can be removed and then pushed sideways by AGVs while the second is then loaded into the autoclave.

We pass skins for the A220 center wingbox on racks. Sanchez notes that Aernnova continues to align with Airbus ramps in production rates. For the A220, Airbus is targeting 14 aircraft/month by 2026. As we walk away from the autoclaves toward the NDT area, we pass skins for the A350 HTP on tools after curing, an upper spar for the A350-1000 engine pylon and three racks of net-shape stringers for the A350 HTP as well as outer skins for a dozen A350 pax doors.

Inspection and assembly

The NDT area features a large squirter UT cell by GE and a robotic UT cell by Tecnatom that has two sections: one for a jig that can use a water squirter on the left and an immersion tank on the right. “We use the GE squirter cell for larger parts because they must be inspected one by one,” says Sanchez. “That was the first machine we had, so certain parts are specified to be inspected with it. However, it’s better to inspect small parts in the Tecnatom immersion tank.” He notes the GE machine can do pulse-echo but not TTU, and both cells can do C-scans.

For the Tecnatom cell, a scanning fixture can be rolled into the left section and inspected with the robot using a water squirter. Meanwhile, an overhead crane lowers a fixture that is loaded with many parts — e.g., 15 ribs or two spars — into the immersion tank. “While we are scanning in the tank, we are preparing the load in the non-immersion side next door,” says Martinez. “We then move the robot over to do the non-immersion scanning while we remove scanned parts and reload the tank. We are using phased array UT with 128 transducers so we can cover a large area quickly. However, before we scan, we must debubble the water in the tank in order to get an accurate image.”

This cycle is repeated continuously, as every part produced here is 100% inspected, notes Martinez. “We also have stations where manual UT inspections are completed to review areas flagged for anomalies.” He adds that all areas of every part must be scanned, especially radii and flanges, because most of these parts are structural and considered flight- and/or safety-critical. We walk past a 787 APB sitting ready to be scanned. There are also racks of A350 MLGB bulkheads, as we enter a large assembly area.

Here, we see 787 APBs being assembled and the banner on the wall from Boeing Charleston. Titanium fittings are attached all the way around the 4.2-meter-diameter bulkhead, which requires stacked drilling of titanium/CFRP/titanium. “We drill this in one shot with an automatic drilling machine,” says Sanchez.

Racks of finished A220 center wingbox skins sit next to A350 HTP and MLGB bulkhead assemblies, the latter a large semicircle with stiffeners. We pass a small cell that Sanchez describes as a development to automate the previously manual job of sealant application. “In the past, this took a lot of time,” he explains. “It also required skilled artisans because the sealing is functional, but the application must also be very neat to provide a high-quality finish. Such skilled personnel are harder to find, and automation will improve efficiency to meet higher production rates.”

We see fittings being installed in spars for the A350 HTP. Martinez explains that while some are mechanically attached, others are bonded and so receive four chicken rivets, two at each end, one on each side of the stiffener flange. We exit this area back into the offices and main lobby.

Ready for the future

Every composites manufacturer has a personality. Aernnova’s is confident, but not showy. It pursues new technologies and automation but as a means to achieve improved, higher rate production. It does invest in new capabilities, but in a measured, practical way with a view to actual production. As a Tier 1 supplier, it must be extremely conscientious, explains Castillo. “We have no room for less-than-optimal processes and operations.” And yet, it is obvious that engineering and engineers form the spine of the company, providing a kind of veritas, stability and direction.

This is key now more than ever. “The industry has changed,” notes Castillo. “After the pandemic, making decisions of where to go is much more challenging. But we are ramping up Hamble and Evora, and we continue to mature automation and new technologies across all our composites sites, including for RTM, press forming and other out-of-autoclave processes. We will launch thermoplastic composites in 2024-25, aiming for TRL 6 by 2026. For now, we will push to meet the demands of increased A320, A350 and A220 production.”

However, he adds that Aernnova Composites sites have capacity for growth and will continue to diversify within the company’s aerospace focus. “We have decades of expertise in engineering and production, combined with a wide range of capabilities that provides real benefits in producing lighter, higher performance and high-rate structures for all types of future aircraft.”