Conventional or towbarless tractor?

Picture: TPX-200-MTX-E 

Another strong performance of the pushback market is expected in 2024, say leading GSE manufacturers.

Conventional tow bar tractors are still popular for well-established operations although operators are increasingly turning to electric in this category to “future-proof their fleets”. Likewise electric towbarless (TBL) tractors are becoming the customer’s choice of preference at congested airports.

“The gap between conventional and electric units is closing with more and more customers choosing electric tractors,” said Daniel Davis, Sales Manager UK & Ireland / Parts & Services EMEA at Trepel. “We have been pleasantly surprised to note that the uptake of electrification has grown across all regions.

Trepel’s Charger380 TBL, ideal for both widebody and narrowbody aircraft, is still the most powerful and fastest tractor in its category, “unbeatable”, he adds, in terms of performance and capability.

Its Challenger conventional range is also very popular globally. “Operators love the driver cabs, with options like heated front and rear screens, electric mirrors and rear view cameras – it is simply best in class,” said David Bellavance, Research & Development Manager Aircraft Tractors, at Trepel.

Trepel’s sales have outstripped capacity in 2023 and remain extremely strong globally. Bellavance said customers were still being impacted by inflation and staff retiring across the industry, with ‘strained supply chains’ affecting some operations.

“Lead times are coming down though, so we can look forward positively as these things stabilise and improve going forward,” he said.
CEO Valentin Schmitt, and Yves Crespel, Alvest Group Communication Director, say TLD also experienced strong demand throughout the year across its electric pushback range, which is being driven by the aviation industry’s goal to become more sustainable.

“TLD has developed several technologies to make the pushback market greener with electric drivelines and alternative power sources from hybrid to batteries or hydrogen as well as leaner with remote controlled machines and telemaintenance solutions,” said Schmitt.
TLD is expecting 2024 to be another solid year for the pushback market due to China rebounding and Asia accelerating.

“It will be very different on the supply side because supply chain issues are now largely behind us and our factories have increased their capacity by 50% in 2023, after a 50% growth already in 2022,” explained Schmitt. “The launch of our Indian factory during the summer of 2023 has also allowed us further capacity.”

Two PHOENIX E at Leipzig Airport

Stavros Hatziioannou, VP of Sales and Service, at Goldhofer, says finding a supplier to deliver immediately remains a challenge to keep up with high demand as fleets are growing fast. “We are facing a market that is willing to choose the supplier that is able to deliver straight away,” he said.

He went on to say how Goldhofer can look back on a very successful year with the PHOENIX towbarless tractor performing extremely well, plus the increasing demand for flagship model, the PHOENIX E. This fully electric model, presented at the International GSE Expo in Vegas, was the 999^th towbarless tractor built and sold by Goldhofer.

“PHOENIX E offers a wide range of applications and is capable of handling around 70% of all passenger aircraft types in the market. This makes PHOENIX your first choice,” said Hatziioannou said: “Goldhofer’s flagship has received a lot of reception and customers are convinced of the product and the technology. Huge ground handlers, airports and airlines trust in PHOENIX E.”

With its modular battery concept, PHOENIX E, has a lithium-ion battery capacity of 66-165 kWh depending on operational requirements. A hybrid solution with a range extender powertrain is also available.

A PHOENIX E demo unit is planned to be operated in Warsaw for possible future investments in e-mobility as part of a partnership with Welcome Airport Services and will be tested by LS Airport Services. The unit has already been operating at Frankfurt Airport since January 2022.

Hatziioannou believes demand for electric units will continue to play a growing role in airport ground support, not only because they are more cost-effective in terms of energy efficiency and less maintenance but also environmentally due to its zero emissions.

The TPX-200-MTX-E is designed to perform push and pull operations from narrowbody to widebody aircraft up to 380t

Will conventional tractors be phased out?
Conventional tow bar tractors still currently dominate the market, especially for simple pushback operations, explains Hatziioannou but depends on the operational requirements.  

“It depends on the preferences of the airport and what the exact tasks are at the airport,” he said. “We see in some regions a preference in towbarless, but in others still a focus on conventional. A slow transition towards towbarless technology is recognisable, driven also by experiences made by customers.”

However, he states customers are turning to electrify conventional tractors to future-proof their fleets. Another advantage of towbarless technology is the potential savings in personnel required for aircraft handling, a “further increase in efficiency”, meaning that towbarless tractors will become increasingly important for pushback operations in the future. “Nevertheless, conventional tractors will continue to play a role for many customers and regional markets in the future,” he added.

Danny Vranckx, CEO of Aviaco GSE, which sells and leases used and refurbished GSE including conventional and TBL tractors, says there are merits for using both tractors, but ultimately, agrees it depends on market requirements. For example, it would not be recommended for African countries to buy towbarless. They don't have the technical expertise and spare parts network to maintain them in case of a breakdown. So, in that case, conventional tractors are a reliable and cheaper option.

“The downside of the conventional tractors is that they need a two-man operation to connect the tow bar between the aircraft and pushback tractor. They need a different tow bar for each type of aircraft too, costing roughly 6,000 euros per unit,” said Vranckx.

“Towbarless tractors work better at larger, busier airports where they can be moved quickly from one aircraft stand to another as well as be used on multiple types of aircraft,” he added. 

Trepel's Charger 380

Davis at Trepel agrees conventional tractors are as popular as they have ever been over the years, however, long distance towing or TBL taxiing to runways has demonstrated there can be huge fuel savings by the enhanced use of TBLs, with electric towbarless tractors making even more sense.

“Towbarless tractors are a must for maintenance and integrate towing with a much safer operation while conventional tractors are often a preferred option for pushback, mostly for ground handlers,” said Schmitt at TLD. “This is slowing changing though as the electric efficiency for a towbarless tractor is much higher than a conventional one because you do not need to carry the weight all the time. It is also much more ‘future-ready’ with remote control operations, steering and drive-by-wire systems.”
He said a good example of this evolution has been of the TPX-100-E that has now become a “world standard for narrowbody pushback operations”.

The TPX-200-MTX-E is TLD’s new fully electric tractor, which has received very positive feedback from the market, with several months of production on order. It also comes as a remote-control version and soon could be hydrogen-powered with the same driveline. Again the TPX-50-E battery powered conventional tractor has won plaudits with customers for its modern design and smart features with li-ion batteries and remote control and drive-by-wire technology. It is able to push and tow a large range of aircraft, from regional aircraft to narrowbodies including B737 NG3/MAX and A321. 

Lektro 88i
JBT AeroTech’s Lektro 88i next-generation TBL tractor is also making waves in the industry. Lektro, before it was acquired by JBT actually, built the world’s first towbarless electric tug called the Airporter. The battery-powered Lektro TBL 88i is suitable for both business and commercial jets. Originally developed in cooperation with Gulfstream, JBT AeroTech has just finished modernising the 88i with the addition of an onboard PLC.

“Combined with AC drive motors it offers regenerative braking, which is advantageous in increasing your drive time per charge,” said Jesse Long, Director – Sales & Customer Care, Ground Support Equipment - Lektro. “You can also customise individual functions of the vehicle to make the operator’s life not quite as frustrating.”

He explains the positive dynamics of a TBL: by removing the tow bar, it allows the tractor to be directly attached to the aircraft.
“There's a single pivot point where all the nose weight of the aircraft is actually working to your advantage, it's basically placing all that weight directly over the drive axle of the tractor,” he said.

“Many times, for example, with the B250 [conventional tractor] that handles heavier aircraft, you have to add more ballast weight to be able to compete against that heavier aircraft weight and the inertia and everything that brings with it. In our case [i.e the Lektro), the heavier the aircraft, naturally, the more ballast weight that's automatically being added to the tractor and directly over the drive axle. So there's no ballasting it up or anything like that necessarily, making the towbarless concept a big deal.”

He added: “There's just some operations that have been established for years around a conventional pushback type of operation. They’ve invested in all the tow bars, they have the people trained, and all the spare parts. With newer operations this isn’t the case so they [the customers] have to establish the dynamics of the operation to know which technology is more ideal.”

The Lektro 88i comes with both lead-acid and lithium battery options but Long said it depends on customer requirements. “Worldwide the vast majority of our vehicles remain lead acid. United has been the main customer of ours that’s been buying lithium batteries. It’ll change as technology becomes more affordable and more common, but I still remain a strong advocate of lead acid in our particular equipment, it’s very cost-effective. You’ll drive this tractor for six hours before you need to charge it and it’s just so easy to maintain.”

He added that the lead-battery capacity has increased from 72V to 80V, (two 40V battery packs). The hydraulics and electric harnesses have been moved to one side to increase the battery base footprint, making it easier for maintenance and servicing.

“In fact, your main hydraulic manifold is right underneath the easily removable panel. So if you need to do any emergency procedures, like lowering the cradle down to release an aircraft after a breakdown or anything like that, your emergency functions are all underneath that panel.”

The biggest change to the chassis is the ‘topside’ access to the vehicle, making it safer, easier and more reliable. “There's literally no reason to get under the vehicle to maintain anything,” said Long.

Another impressive feature of the Lektro 88i is the option to upgrade and have a second driving station, especially if operators are doing long distance towing.

Remote control tugs
One company which is offering the market a completely alternative pushback experience is Mototok. In 2003, it developed the first wireless remote controlled electrical tug in the world for small private aircraft. Five years later, this next generation machine was produced for large business jets, then later developed in 2007 for narrowbodies at MRO facilities. Its narrowbody machine started being used for pushback operations in 2016 and the company has never looked back, now with many machines in operation around the world.

“It is important to note that right from the onset some 20 years ago, Mototok has produced electric pushback tugs. We never used ICE technology but electric only, so you could say that Mototok is pioneering the vision for electric GSE around the world.

“We were the first GSE company to launch multiple electric remote control operated pushback tugs at London Heathrow,” said Thilo Wiers-Keiser, Sales and Marketing Director at Mototok.

So impressive are the machines that since British Airways started using 28 of Mototok’s Spacer 8600 models, it has resulted in a 54% reduction in delays at Terminal 5 at Heathrow. More than 350,000 pushbacks have been performed at the terminal using the Mototok units over the past two years.

Now Mototok has launched the new Spacer 8600NG, an updated version of the existing model, which has already received a positive response from existing and potential customers. The NG is certified to A321 XLR and carries multi-aircraft handling approvals. It has powerful drive motors with the ability to be disengaged for towing with an onboard tow bar. 

Mototok tugs can also be adapted for military operations, with special fittings and accessories. The other main benefits of deploying Mototok machines are their extremely small footprint, with significant savings in maintenance and training. It loads and unloads the nosegear automatically and is operated by just one person, meaning the operator is his own wing walker. The machines are suitable for B737, Airbus A320 and MHI/Bombardier CRJ series.

“We pride ourselves in this technology,” said Wiers-Keiser. “We are planning several Spacer 8600 NG showcase trials, with Airbus placing an order, which is a great endorsement for our product. We have also received a multiple unit order from a Far East airline.”
Mototok is also working in North America and is upbeat on the progress made in that market. “We have several upcoming trials in various parts of the world and we feel that this will propel Mototok to the next level,” continued Wiers-Keiser.

He said Mototok was seeing an increased demand and interest from various parts of the world as more and more airports and airlines learn about its pushback concept. “Our network is growing around the world. We are also making strong inroads in the MRO sector,” he said.

Equally Wiers-Keiser said he was thrilled other GSE manufacturers were also investing heavily into electric GSE, “not only for the environment but the greater good of the people”.

Wiers-Keiser says the lead-acid battery operated machines can overcome the challenges of having a lack of charging infrastructure at airports, adding that: “Chargers are not standardised around the world so hence why we provide an onboard charger with our tug. We are breaking these barriers by demonstrating our presence at various GSE shows and exhibitions around the world. Our extensive sales, marketing and business development network is helping us to reach out to customers in various parts of the world.”