Amid persistent market constraints within commercial aviation, profit margins remain highly sensitive to operational inefficiencies. Ongoing OEM delivery bottlenecks have forced operators into short-term, expedient habits that collaterally drive-up maintenance and operational expenses. While many of these systemic challenges lie beyond an operator’s control, maintaining long-term economic viability necessitates a shift toward self-sustaining, resilient solutions. In this context, optimising hydraulic aircraft systems should be at the very forefront of operational strategies for fleet management.
The hydraulic imperative
Serving as the “muscles” of an aircraft, hydraulic systems convert and channel pressurised fluid to power critical flight components. From landing gear and brakes to flight control systems, aircraft mobility is largely contingent on the integrity of these mechanisms and the fluids that course through them.
Hydraulic systems rarely fail suddenly, however. Buried deep within an aircraft’s frame, latent issues often go undetected and compound over time. Such costly and preventable failures shorten fleet lifespans and further tighten operator margins. Given their critical role, the effective management of these systems is of paramount importance.
Inferior fluids and their false economy
Market-driven incentives to cut costs with cheap, uncertified hydraulic fluids risk a false economy. In most cases, cheaper fluids result in greater long-term expenditures caused by high fuel burn, accelerated fluid degradation, and heightened maintenance demands stemming from poor chemical stability.
Driven by high-pressure pumps and extreme heat from brakes, hydraulic systems in more modern aircraft experience severe thermal stress, with temperatures soaring beyond 200°C. While standard mineral-based fluids are complementing the specific, lower-temperature aircraft they are designed for, using them in these high-heat modern systems poses severe risks. Under these conditions, the wrong fluid class can quickly degrade, leading to a compromised system and catastrophic fires if pressurised leaks hit hot components. To mitigate these risks, operators must diligently select highly fire-resistant formulations with OEM-approved seal materials.
Lower grade fluids can be more susceptible to the impacts of contamination. Hydraulic systems can accumulate moisture triggering hydrolysis in degraded fluids and producing corrosive acids that damage vital components.
Managing hydraulics is further complicated for airlines operating mixed fleets of aircraft with distinct OEM requirements. While the chemical stability of a fluid is vital, its total effectiveness in improving safety, efficiency, and system longevity hinges on its compatibility with the aircraft itself. A fluid that works for one airframe may not necessarily be ideal for another; thus, using a single fluid universally across a fleet to streamline inventory could prove more hazardous than convenient.
ExxonMobil’s pole position
In response to the complex demands of mixed-fleet management, ExxonMobil delivers a definitive solution through its advanced HyJet IV-A plus, HyJet V, and Mobil Aero HF product lines. With approvals from many OEM’s including Boeing, Airbus, Embraer and Bombardier for Mobil HyJet Hydrulic fluids, ExxonMobil’s hydraulic solutions help airlines consolidate their fluid inventory. This strategic offering helps to reduce maintenance costs, minimise the operational complexity of managing multiple fluids, and limit cross-contamination risks.
The advanced chemistries in ExxonMobil products prevent fluid breakdown and hydrolysis-induced contamination, providing enhanced deposit control as well as excellent protection against wear, rust, and corrosion. These qualities help extend equipment life and component longevity across a fleet. Meanwhile, its fire-resistant, Mobil HyJet IVA+ and Mobil HyJet V’s formulations, supports high-temperature stability and optimal low-temperature viscosity. With these protective thermal properties, ExxonMobil’s fluids promote system integrity and help to safeguard an aircraft from devastating fires.
ExxonMobil’s premium fluids also feature an industry-leading, low-density composition that can help to significantly reduce aircraft weight and lower fuel burn. These efficiency gains are vital given the industry’s current aging fleet crisis, which has forced operators to extend the service lives of legacy aircraft that consume up to 20% more fuel than next-generation models.
Standardisation at Kalitta Air
The real-world value of ExxonMobil’s solutions was on full display during a fleet-wide optimisation project with cargo carrier, Kalitta Air. Operating a mixed freighter fleet of Boeing 747-400s and 777s, Kalitta Air faced the complex challenge of navigating tight schedules while optimising aircraft ground time for maintenance and increasing component reliability. When long-term partner Boeing identified an opportunity to standardise jet oils across Kalitta Air’s fleet to streamline operations, the carrier spotted a similar opportunity in its hydraulic systems and proceeded to convert its hydraulic fluid to ExxonMobil’s HyJet IV-Aplus.
Supported by hands-on training and assistance from ExxonMobil experts, the transition was executed efficiently using the “top-off” method which limited maintenance downtime needed for the conversion. By standardising product lines across different fleet types, the cargo carrier successfully optimised operations and improved fleet reliability. Kevin Jackson, maintenance fleet manager at Kalitta Air, noted that the ease of managing a single product “diminished human factor error” and simplified maintenance procedures.
Download the report below to discover how ExxonMobil’s hydraulic solutions and expertise help to improve mixed-fleet management, reliability, and profitability.
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