Cargo Gliders Aim To Slash Fuel

Sky Trains: Could Towed Gliders Revolutionise Air Cargo and Slash Emissions?

The air cargo industry stands at a crossroads. It faces immense pressure to reduce its significant carbon footprint and soaring operational costs. Fuel expenses and a pilot shortfall further compound these challenges. However, an audacious American startup, Aerolane, proposes a solution. Their idea draws inspiration from migrating geese and World War II technology. Aerolane aims to transform air freight by towing autonomous, unpowered cargo gliders.

Learning from Nature's Fliers

Nature often provides elegant solutions to complex problems. Geese journeying in their characteristic V-shape demonstrate an innate understanding of aerodynamics. Each bird, except the leader, benefits from the upwash created by the wingtip vortices of the bird ahead. This "vortex surfing" allows the flock to conserve significant energy during long migrations. Scientists have long studied this phenomenon. Aerolane now seeks to apply this principle to modern aviation, promising a new era of efficiency in air transport.

Aerolane's Bold Proposal

Aerolane, a Texas-based company, intends to fundamentally disrupt the air cargo market. Co-founders Todd Graetz, Doron Appelboim, and Gur Kimchi lead this ambitious venture. Graetz brings experience from BNSF Railway's drone program and FAA advisory committees. Kimchi was a co-creator of the Amazon Prime Air aerial dispatch initiative. Appelboim contributed as Chief UAS Test Pilot at Amazon Prime Air and has a background with Israel Aerospace Industries. Their combined expertise fuels Aerolane's mission. They aim to make air transport significantly cheaper and cleaner by harnessing the power of gliding.

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The "Aerocart" Emerges

Aerolane's key innovation is the "Aerocart," an autonomous towed cargo glider. Early prototypes, including one nicknamed the "aerial piano" due to its initial gliding characteristics, helped refine the concept. These test aircraft, sometimes converted Pipistrel Virus or Velocity SE planes, utilised smoke and cameras. This allowed engineers to visualise and analyse air vortices. Tension readings from the connecting cable indicated when the glider successfully "surfed" the lead aircraft's wake. Data from these tests now informs the development of sophisticated autonomous guidance systems for the Aerocarts. These gliders are designed to be simple, lightweight airframes, packed with cargo and equipped for autonomous flight.

A New Model: The Glider Convoy

Aerolane pictures a primary aerial vehicle, itself laden with freight, pulling a single Aerocart or several. These unpowered aerial vehicles would independently follow the path behind the lead airplane, significantly reducing drag. Upon reaching their destinations, the Aerocarts would detach and land independently. This system promises substantial fuel savings. Fuel expenditure would solely associate with the primary aerial vehicle's engines, which benefits from a marginally higher fuel burn despite the increased overall payload. Aerolane suggests this approach could slash air cargo costs by as much as 65%.

Industry Parallels: Airbus Explores Wake Surfing

The concept of harnessing wake energy is not exclusive to Aerolane. Aerospace giant Airbus has explored a similar idea with its "fello'fly" project. During 2021, Airbus conducted trials where a pair of its A350 jets traversed the Atlantic Ocean in close formation, separated by approximately 3 kilometres. The trailing aircraft benefited from the foremost aircraft's wake, reducing fuel burn and CO2 emissions by 5 to 10%. Unlike Aerolane's towed glider concept, fello'fly involves two powered aircraft maintaining precise formation. The project, now evolved into the GEESE project with EU Sesar funding, continues to develop the technology, aiming for potential commercial application. Delta Air Lines plans to participate in further flight trials.

Pilot Scepticism and Safety Scrutiny

The introduction of large, unpowered gliders into commercial airspace naturally invites scrutiny from experienced aviators. Rigorous aviation safety rules oversee all airborne activities. A paramount worry centers on the lead airplane's capacity to detach the connecting cable securely at any juncture during the journey. Moreover, the self-piloting glider must then dependably find its way to an airstrip, avoiding any hazard to communities below. Aerolane recognizes these issues. The enterprise indicates its freight gliders will possess a compact electrical engine powering a propeller. This mechanism serves as a crucial backup, offering sufficient thrust for another landing attempt should an initial approach seem incorrect, or to reroute the craft to a different, proximate airfield.

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Aerolane’s Commitment to Practicality

Todd Graetz addresses worries by pointing out the company has currently practicing commercial aviators on its team. These professionals bring a hard-headed, practical perspective to the project's development. Aerolane also engages external advisors to act as "devil's advocates," thoroughly scrutinising their plans and assumptions. This internal and external review process aims to ensure the feasibility and safety of their innovative approach. Graetz reports significant interest from major freight businesses. These companies constantly seek ways to reduce per-delivery costs, making Aerolane's potential fuel and operational savings highly attractive.

Economic and Environmental Drivers

The air freight industry faces compelling reasons to innovate. High fuel costs represent a primary operational expense for airlines. Exhaust from jet powerplants faces growing ecological examination, pushing the sector towards greener alternatives. Additionally, a persistent pilot deficit adds further pressure to find more efficient operational models. Aerolane's towed glider concept directly addresses these critical issues. It promises dramatically reduced fuel consumption per tonne-mile of cargo. This, in turn, leads to lower emissions and less reliance on flight crews for the unpowered sections of the journey.

Expert Opinions: Promise and Public Perception

James Earl, an aviation consultant with past experience as an RAF helicopter aviator, perceives value in Aerolane's method. He thinks that leveraging slipstreams and cooperative airborne endeavors present sensible efficiency improvements. Earl considers all advancements within the freight sector to be positive. Nevertheless, he also warns about the difficulty of achieving public endorsement. Securing broad acceptance for non-powered freight aircraft operating above populated zones will necessitate strong safety showcases and clear explanations. The unpowered craft must have substantial unpowered flight capability to guarantee secure landing alternatives should the lead airplane experience a critical issue.

Navigating Regulatory Hurdles with the FAA

Regulatory bodies, particularly the US Federal Aviation Administration (FAA), will undoubtedly approach this novel technology with caution. The FAA is already under pressure concerning aircraft safety and certification processes. Aerolane states its complete adherence to all FAA directives received thus far. The company acknowledges the FAA's inherently risk-averse nature, stating it is fundamental to the agency's mission of ensuring air safety. Aerolane is actively working through the FAA's supplemental type certification (STC) process. The company recently established a flight operations headquarters at Perot Field Fort Worth Alliance Airport, a major US logistics hub, to further this process.

A Convert's Perspective: From Doubt to Advocacy

Fred Lopez, an experienced professional with three decades and six years dedicated to flight operations at the major freight carrier UPS, first held profound reservations concerning freight gliders. His professional life centered on enhancing air cargo financial efficiency. Yet, the potential for significant fuel conservation ultimately persuaded Lopez regarding Aerolane's viability. He currently participates as a member of their consultative panel. This endorsement from an industry insider highlights the compelling economic arguments underpinning the Aerocart concept. His journey reflects a growing recognition that unconventional solutions may hold the key to future air freight efficiency.

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The Relentless Pursuit of Efficiency

Civil aviation consistently seeks methods to reduce fuel consumption. When aircraft wing extremities that curve upwards, known as winglets, transitioned into a common characteristic in aircraft construction, this advancement led to fuel expenditure decreases near five percent. Aerolane’s pulled gliders, conversely, suggest a much more substantial reduction in fuel usage for each cargo unit. Because the gliders use no fuel themselves, and the lead airplane only needs a slight rise in its fuel usage, the total efficiency improvement for a considerable consignment might be groundbreaking. This aligns with the industry's broader push for sustainability.

A Phased Introduction to Autonomy

Aerolane plans a carefully staged approach to introducing its technology. The initial Aerocart design will incorporate their autonomous flight systems alongside a human "safety pilot" with the leading aircraft overseeing the glider's operations. Fred Lopez notes this strategy should simplify the FAA certification process. He emphasises that Aerolane does not aim to overhaul every aspect of air cargo operations simultaneously. This pragmatic approach acknowledges the complexities of integrating such a novel system into the existing aviation ecosystem.

The Ultimate Goal: Pilot-Free Aerial Cargo Convoys

The long-term vision for Aerolane involves fully autonomous operation driven by artificial intelligence. Fred Lopez describes this long-range goal as aiming "to remove the human aviator from control," certainly for the glider's travel phase. This points towards a future where "sky trains" – a lead aircraft towing multiple uncrewed Aerocarts – become a common sight. Such a system could significantly increase cargo capacity per flight movement and further reduce reliance on pilot numbers for the overall freight task. The company anticipates its first Aerocart cargo glider system will enter commercial service later this year.

Beyond the "Aerial Piano": Expanding the Horizon

Should Aerolane’s uniquely named "aerial piano" craft and its subsequent, more developed Aerocart versions achieve success, the implications could extend beyond bulk cargo. While current development focuses on freight, the core principles of towed flight and vortex surfing might, in the distant future, find applications in other aviation sectors. Ongoing research globally into formation flight for fuel efficiency, like the Airbus initiatives, underscores the persistent interest in these aerodynamic benefits. The US Air Force has also explored autonomous cargo gliders, like the "Grasshopper," for resupplying troops in high-risk environments, indicating military interest in similar concepts.

The Air Cargo Innovation Landscape

Aerolane operates within a broader context of innovation aimed at making air cargo more efficient and sustainable. Other companies are developing autonomous cargo drones for last-mile delivery. Some explore modern airships for niche cargo roles. Significant investment also flows into Sustainable Aviation Fuels (SAF). SAFs, derived from sources like used cooking oil or agricultural residues, can reduce lifecycle carbon emissions by up to 80% compared to conventional jet fuel but are currently expensive and scarce. Aerolane's mechanical solution offers a different pathway to emissions reduction.

Greening Air Freight: A Significant Impact?

The potential environmental benefits of widespread Aerocart adoption are substantial. Air transport currently accounts for approximately 2.5% of global CO2 emissions. By dramatically reducing fuel burn per tonne of cargo, Aerolane's technology could help the air freight sector make significant strides towards its decarbonisation goals. This aligns with global efforts to combat climate change and the aviation industry's commitment to achieve net-zero carbon emissions by 2050. The reduced reliance on fossil fuels also offers greater energy security and cost stability for operators.

A Calculated Leap for Air Logistics

Aerolane’s "sky train" concept constitutes a considerable risk, but one with potentially enormous rewards. The company, having secured $10 million in seed funding in late 2023, is actively flight-testing its Aerocart prototypes. It aims to demonstrate that mimicking nature's efficiency, combined with modern autonomous technology, can overcome the immense challenges of revolutionising air cargo. Success hinges on proving a high degree of safety, navigating complex regulatory landscapes, and gaining public trust. If Aerolane can achieve these, its towed gliders might indeed redefine the future of air freight.