Mobil HyJet IV-A Plus
Mobil HyJet IV-A Plus is a high-performance phosphate ester aviation hydraulic fluid developed for use in commercial and business aircraft. It is designed to meet the demanding requirements of modern aviation systems, offering superior performance in key areas such as thermal stability, corrosion protection and fluid longevity.
One of the key advantages of Mobil HyJet IV-A Plus is its outstanding high-temperature stability. The formulation resists thermal degradation and maintains performance under extreme operating conditions, helping extend both fluid and component life. Testing such as the Airbus NSA 307110 Ampoule Test demonstrates its ability to outperform many competitive Type IV fluids in maintaining stability over extended periods.
Mobil HyJet IV-A Plus also offers excellent corrosion and rust protection. It helps protect hydraulic system components from moisture-related damage, ensuring reliable operation and reducing the risk of costly repairs or failures in critical aviation systems.
Another important benefit is its low density. As highlighted in the performance data, the fluid is one of the lowest density Type IV aviation hydraulic fluids available, which can contribute to reduced aircraft weight and improved fuel efficiency over time.
Mobil HyJet IV-A Plus is specifically recommended for use in aircraft hydraulic systems requiring Type IV phosphate ester fluids, including those meeting specifications such as SAE AS1241C, Airbus NSA307110N and Boeing BMS 3-11. It is widely used across a range of commercial aircraft platforms and is suitable for mixed fleet operations.
Physical characteristics include a density of approximately 8.35 lb/US gal at 60°F and a specific gravity of 0.996. The fluid has a kinematic viscosity of approximately 10.6 mm²/s at 100°F, 3.6 mm²/s at 210°F and 2.6 mm²/s at 127.6°C, with excellent low-temperature fluidity of approximately 130 mm²/s at −15°F and 1320 mm²/s at −65°F. It has a viscosity index of around 280, a flash point of approximately 349°F, a fire point of approximately 370°F and an autoignition temperature of approximately 800°F.
