HyJet™ V

ExxonMobil aviation , Estonia

Fire-Resistant Phosphate Ester Aviation Hydraulic Fluid

Product Description

Mobil HyJet V is a Type V fire-resistant phosphate ester hydraulic fluid, which is superior in thermal and hydrolytic stability to commercially available Type IV hydraulic fluids. Better stability means the extent of fluid degradation in aircraft systems will be less than Type IV fluids, in-service fluid life will be longer, and consequently aircraft operator maintenance costs may be lower.

HyJet V provides excellent high and low temperature flow properties (kinematic viscosities) and rust protection. HyJet V has also demonstrated an improvement over the erosion protection performance afforded by Type IV fluids.


Features and Benefits

Mobil HyJet V offers the following key features and benefits:


Advantages and Potential Benefits

Higher stability than Type IV fluids

Longer fluid life,

Lesser need to replace fluid due to degradation,

Reduced hydraulic system maintenance costs

Meets Boeing BMS 3-11 and SAE AS1241 Type IV and Type V requirements

Improved flammability characteristics over meeting just the Type V requirements

Low density

Reduced weight of the hydraulic fluid carried by aircraft,

Reduced aircraft fuel consumption,

Lower operating costs

Excellent rust protection

Reduced risk of equipment damage in the event of major water contamination

Excellent low and high temperature viscosity balance

Precise hydraulic system control and response even during extended range/polar flights,

Longer aircraft hydraulic system equipment life

Excellent deposit control

Longer aircraft hydraulic system equipment life,

Reduced maintenance costs

Improved protection against electro-chemical corrosion (erosion)

Protection against servo valve and pump damage

Fully compatible with all approved Type IV and Type V phosphate ester hydraulic fluids

Flexibility in use by airline operators



Mobil HyJet V is designed for use in commercial aircraft phosphate ester hydraulic systems. It meets the SAE AS1241 requirements and is included in commercial and business airframe manufacturer Qualified Products Lists, as shown below. It is compatible in all proportions with commercial Type IV and Type V phosphate ester aviation hydraulic fluids.


Specifications and Approvals

This product has the following approvals:

AIRBUS NSA 307110N -Type V

BOEING, BMS 3-11P, Type V, Grade A and C

Boeing-Long Beach DMS2014H - Type 5



Properties and Specifications



Acid Number, mgKOH/g, ASTM D974


Autoignition Temperature, F, ASTM D2155

>427 (800)

Bulk Modulus, Isothermal secant at 100 F/3000 psi, psi, ASTM D6793


Calcium, ppm, ICPES


Chlorine, ppm, XRF


Coefficient of Thermal Expansion, 25 to 100 C, per degree C, API MPMS 11.1

0.00086 (0.00048)

Conductivity @ 20 C, MicS/cm, ASTM D2624


Density @ 60 F, lb/USg, ASTM D4052

1.000 (8.35)

Fire Point, Cleveland Open Cup, °F, ASTM D92

186 (366)

Flash Point, Cleveland Open Cup, °F, ASTM D92

174 (346)

Foam, Sequence I, Collapse Time, s, ASTM D892


Foam, Sequence II, Collapse Time, s, ASTM D892


Foam, Sequence III, Collapse Time, s, ASTM D892


Four-Ball Wear Test, Scar Diameter, 10 kg, 600 rpm, 1 h, 75 C, mm, ASTM D4172 (mod)


Four-Ball Wear Test, Scar Diameter, 4 kg, 600 rpm, 1 h, 75 C, mm, ASTM D4172 (mod)


Four-Ball Wear Test, Scar Diameter, 40 kg, 600 rpm, 1 h, 75 C, mm, ASTM D4172 (mod)


Kinematic Viscosity @ 100 F, mm2/s, ASTM D445


Kinematic Viscosity @ 127.6 C, mm2/s, ASTM D445


Kinematic Viscosity @ -15 F, mm2/s, ASTM D445


Kinematic Viscosity @ 210 F, mm2/s, ASTM D445


Kinematic Viscosity @ -65 F, mm2/s, ASTM D445


Potassium, ppm, ICPES/AA


Shear Stability, % Kinematic Viscosity Loss, 40 C, %, ASTM D5621


Sodium, ppm, ICPES


Specific Gravity, 25 C/25 C, ASTM D4052


Specific Heat Capacity, cal/g-deg.C, Reference


Sulfur, ppm, ICPES/XRF


Thermal Conductivity at 40 C, Cal / (cm s oC), Reference

33x10^-5 (0.0799)

Viscosity Index, ASTM D2270


Water Content, mass%, ASTM D6304


Pour Point, °F, ASTM D97 / ASTM D5950


NAS 1638 Class, HIAC, ISO 11500



Health and safety

Health and Safety recommendations for this product can be found on the Material Safety Data Sheet (MSDS) @ http://www.msds.exxonmobil.com/psims/psims.aspx

All trademarks used herein are trademarks or registered trademarks of Exxon Mobil Corporation or one of its subsidiaries unless indicated otherwise.


Exxon Mobil Corporation
22777 Springwoods Village Parkway
Spring TX 77389
For additional technical information or to identify the nearest U.S. ExxonMobil supply source, call +1 800 662-4525.

Due to continual product research and development, the information contained herein is subject to change without notification.  Typical Properties may vary slightly.