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Concorde Hydraulic Oil


Concorde also used a special hydraulic fluid, Chevron M2-V.


This is a silicate ester mineral based fluid, as opposed to the phosphate ester based Skydrol, used by the subsonic airliners.


M2-V, is a high temperature fluid of the POLYSILOXANE (Ester Silicate) type, and able to resist temperatures ranging from – 60° C (- 76° F) to + 2300 C (+ 446° F) and having a sufficiently high bulk modulus.


The reason that they went for a different fluid such as M2V was a simple one;
Skydrol is useless at the high temperatures that Concorde operated at, in fact it’s no good at all because it is not chemically stable at very high temperature
They needed something better and in M2V they found the perfect fluid. Another interesting fact is that unlike Skydrol, that attacks paintwork, certain rubber seals, skin, engineer’s eyes etc, M2V is completely harmless you could even wash your hair in it, but I wouldn’t recommend it. 

The main properties of CHEVRON M2-V are as follows :




- 54° c (- 65° F) 2.650 C.S.

38° C (100° F) 16.9 C.S.

99° C (210° F) 5.45 C.s.

177° C (350° F) 2.12 C.s.

Flash point


216° C (420° F)

Fire point


240° C (465° F)

Self igniting temperature


404° C (760° F)

Acidity index


0.04 mg KoH/gm

Density at 15° C (59° F)



Flow point


- 80° C (-110° F)

Vapour tension


0,58 mm Hg at 204° C (400° F)

Thermal expansion coefficient between – 46° C (- 50.8° F) and 260° C (500° F)


0.001 volume unit per 0 C

Bulk modulus


(Adiabatic) at 100° C (212° F)

and 275 bars (3990 psi): 1~1.700

bars (170 psi)

The Hydraulics constitutes the lifeblood and muscle of Concorde. Without the Chevron M2V coursing through the network of pumps, pipes and valves, the lights would be on, but nothing would stir


There are three separate independent hydraulic systems. There are two main systems identified as Green and Blue and a standby system called yellow, which is available at any time for back-up purposes. Each of these systems is powered by two engine driven-pumps.


Certain precautions have to be observed while filling, topping-up or the lowering of the level of the Green, Blue and Yellow hydraulic tanks. Under no circumstances must the hydraulic fluid be mixed with water or any other fluid, you also have to be carful not to allow it to mix with the air. Once any of these substances has contaminated the M2-V, it becomes unusable.




As already stated above, Chevron M2V hydraulic fluid is based on a silicate ester (polysitoxane), with additives. It is light amber in colour and has a slight odour. Contamination by other fluids causes discolouration, and therefore correct storage of Chevron M2V hydraulic fluid is essential to prevent its contamination prior to use. Although Chevron M2V is essentially non-toxic, it must be handled with care at all times.


The cleanliness of Chevron M2V hydraulic fluid must conform to a standard, which defines the cleanliness standard relative to particle the contamination count. Every effort must be made to ensure that the values quoted are not exceeded; otherwise the M2-V becomes useless and therefore unusable.



The maximum contamination levels for Chevron M2V hydraulic fluid, as received from the manufacturer, are detailed below



(MICRONS)                  OF PARTICLES PER 100 ML

5-15                                          7000

15 – 25                                      1500

25 – 50                                        300

50 and above                                20

Fibres                                              3



The level of contamination for fluid used in static test rigs must not exceed the values detailed below:



(MICRONS)                  OF PARTICLES PER 100 ML

5-15                                           14000

15 – 25                                         3000

25 – 50                                           600

50 and above                                   25

Fibres                                                3



The details below show the maximum contamination levels for the aircraft hydraulic systems and ground functioning rigs.


PARTICLE SIZE                           MAXIMUM NUMBER

(MICRONS)                              OF PARTICLES PER 100 ML

5 – 15                                               32000

15 – 25                                               5700

25 – 50                                                1012

50 – 100                                               180

Over 100                                                32

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