What is it that companies like Joby, Archer, Volocopter, and Lilium have in common, apart from the desire to make it big in the advanced air mobility (AAM) market?

Parts made by TE Connectivity.

At the Paris Air Show earlier this year, an eye-catching transparent model of an eVTOL vehicle highlighted the company’s broad portfolio of interconnects, harnessing components, sensors, and fiber optics that are extensively used in various eVTOL aircraft being developed. The parts answer the industry’s call for lightweight components, helping to reduce the overall weight of the aircraft without compromising performance.

Springing into action soon after NASA announced, a few years ago, that it would invest in Electrified Aircraft Propulsion (EAP) research, TE Connectivity began investing time and resources into developing products that suit the needs of such aircraft. The company currently produces more than 120 different parts enabling the next generation of flight.

The company’s extensive involvement in the AAM sector did not happen by chance. “We share with our customers our technology roadmap,” says Matthew McAlonis, Engineering Fellow and Director of Advanced Systems and Architecture for the Aerospace, Defense & Marine business unit at TE Connectivity. “Part of what my team does is look into the future for 5-10 years and work with customers to develop products for when they need them. We talk about timing and aircraft certification because we might have to develop something that must get industry standardized. That way, the products will have the technology readiness level for when the company needs them.”

“There are some eVTOLs flying, just not flying commercially yet,” adds McAlonis. “We have been working with some of the players in the field for several years now. Joby, Archer, Volocopter, Lilium; their aircraft have our products. We make some of the best products in the industry for power switching, wire and cables, connectors, and fiber optics. We are essential to the sector.”

“People ask what is so special about wires,” says McAlonis, who heads the company’s advanced system and architecture team. “You must remember that you are dealing with megawatts of power. We have specific wires for different environments. The typical characterization is temperature. If I have something on an engine, it must run very hot, versus something not. What is different is the different grades of polymers, the conductor selection for the wiring, and the cable construction.”

The range of products that the company produces enables it to provide customized solutions. “Somone might say, ‘I like this product, but I need it lighter.’ Another customer might say, ‘I have really tight spaces.’ Someone else will like a power feeder but want improved flexibility,” says McAlonis. “For equivalent power rating, we can change materials and go to options like aluminum instead of copper. We have to increase wire gauge; copper has a certain bendability while aluminum is stiffer. We have flattened cables and some that are very flexible.”

Focus on Reducing Weight

Unlike conventional aircraft that loses about one-third of takeoff mass due to fuel burn at takeoff and continues to lose weight as fuel is consumed during flight, vehicle weight remains constant in eVTOLs and nearly constant in hybrid-electric aircraft. Reducing the weight of components, therefore, becomes even more critical for such aircraft. With new-generation aircraft carrying more electronics than ever before, the amount of wiring needed is significant; the total weight of all wiring and connectors in a wide-body commercial jet is about 1,814 kg/4,000 lbs.

“Think about how much power you need on a commercial aircraft,” says McAlonis. “If you think of an airplane like the 777, you are carrying around a small village at almost 40,000 feet. You have everything from air conditioning, lighting, plumbing, kitchen, inflight entertainment systems, charging ports, avionics, and radar systems. Think about all the power and energy being generated already. When you generate that amount of power, you need switching products, cable products, connectors.”

The type of cables and power switches used in eVTOLs differ considerably from those in commercial aircraft, says McAlonis. “For electric propulsion, there are a lot of requirements for higher voltages. With a typical commercial airliner, we deal with systems designed around 270 volts. In eVTOLs, because you need a tremendous amount of power, we are seeing applications nearing the 1000 volts range and beyond. High voltage is dangerous. We must make sure that we do the proper testing to ensure safety. In some of these products, like in a battery, many of the components are serviceable but touch safe. And it is important that we make products that are quick and simple to install.”

EVTOLs are even more power intensive than commercial aircraft, “usually orders of magnitude more,” adds McAlonis. When you get into electric propulsion, you need even more cables. You are generating even higher power, to get the lift and propulsion. For higher voltages, you need special cables and next generation power switches. You must have corona-mitigated or partial discharge-mitigated products. Safety and reliability are very important for us as our products need to last for decades.”

Extensive Product Range

McAlonis believes that the wide spectrum of products it has makes TE Connectivity unique. “There are competitors that do power switching. There are some that make cables and connectors. We do the complete architecture. We are doing a lot inside the batteries, to interconnect all the cells together. We are one of the only connector suppliers approved on commercial aircraft engines; These connectors contain a thermal locking switch inside that ensures that the connectors do not fail even if they experience an engine fire.”

The company’s story is one of constant innovation and the ability to anticipate trends in the various industries it is involved in. With hydrogen fuel cell propulsion for aircraft on the cards, TE Connectivity is already making a move.

“As with any other fuel, hydrogen is used for two purposes – for propulsion and for power generation. Airbus has a research and development project called ZEROe; what they are doing is taking generators and burning hydrogen to generate the electricity, for electric propulsion. Downstream, it is still high voltage electrical cables.”

Enabling Green Air Travel

Sustainability is a major focus area at TE Connectivity, says McAlonis. “The first thing we look at is the use of proper materials and the optimization of size and weight. Helping our customers save energy is important for us. The whole eVTOL market depends on reliability and how long you can fly. The longer we can help them fly, the better it is for them. You can save fuel with lightweight products.”

The aviation industry has made a near-total recovery from the pandemic, but McAlonis says supply chain issues continue to persist “There are areas where it is still very sensitive. There is also a void created by retirements; many of those who retired were experts and we do not have that anymore. There are a lot of complex issues that come in with a disruption like that, one that lasted as long as it did. That really affects everybody.

“There were close to 25,000 airplanes flying pre -pandemic,” he adds. “When the pandemic happened, it went down to about 7000 airplanes in service, with more than 15,000 airplanes sitting on the ground. That affected our ability to move our inventory. The market has certainly picked up now. A good supplier will be dependable and able to keep up with the increased demand. That is what we want to be for our customers.”