hydraulics

[mrmungus2002]

just wondering if anyone could help me with this 3 part question as having a bit of trouble with it, or if u know of any sites that might help ???????:ugh:



with reference to an aircraft hydraulic brake system state the function & operation of the following componants:

1) BRAKE CONTROL VALVE
2) PRESSURE GAUGE
3) ANTI SKID UNITS

thanks
MR M

[stevef]

The old CAA Civil Aircraft Inspection Procedures books, which contain this sort of information, have been largely superseded by a downloadable PDF format. http://www.caa.co.uk/cap562
Have a look under the relevant indexed chapters. It's important to have a good grasp of basics in order to understand the workings of the components you mentioned, especially anti-skid units.

[Piper19]

hm, that's a question that rises multiple other questions by me. You can write whole chapters about these 3 things. Function/working would depend on aircraft type.
But in general, anti skid units sense the skidding of a wheel (deceleration) and a modulating valve would then regulate pressure to the brakes, independent from pilot input. They sense it generally by comparing wheel speeds of wheels on the same axle or bogey. (one wheel turning slower = skid). Other aircraft types can measure the wheel speed against aircraft ground speed. A third type is the using of flywheels.

A brake control valve is just the valve that lets hydraulic pressure through according to pilot input (or autobrake input). So, it's installed BEFORE pressure decreasing means such as the anti skid valves.

As for pressure gauges, well...there are a whole bunch of pressure gauges in the brake system. You can have the ones on the brake accumulators, which give you nitrogen pressure on the accu's, and you can have a gauge in the cockpit to give you applied pressure on the (parking)brakes or pressure available to brake (e.g. in emergency braking)

again, this all depends from aircraft to aircraft and other people can add a lot to this