about hydraulic system of 727 nose landing gear retraction system

[mie]

hye..i'm newbie here..i want to get any info about my final year project..first of all,i would like to introduce myself..i'm aviation school student..n i have choose a topic of hydraulic system for 727 nose landing gear retraction system for my Final Year Project..the question here, can anybody tell me where does the nose landing gear for 727 got the fluid to supply it for retraction system..as far as i know there are two hydraulic system that 727 have..which is A system n B system..n also i need the hydraulic diagram that show the connection for 727 nose landing gear retraction system....hope somebody will help me out..thnks

[Fargoo]

Hi and welcome :ok:

There's some good info on this site to get you started

Hydraulic System (http://www.boeing-727.com/Data/systems/infohydraulics.html)

[mie]

THanks fargoo..but i already looked at that diagram before, but i dont see any linkage that connected to nose landing gear retracting system at that diagram..it just have nose landing gear breaking and steering..

[IFixPlanes]

Don´t you see the box "Gear Actuation"?

[hetfield]

727 has three HYD Systems, A, B and stby.

All Gears are A supplied.

[mie]

thnks all of u guys..i have misslook at that 'gear actuation".k thnks u

[DownIn3Green]

Mie...Just as an afterthought...when the nose gear does retract, there are rubber "bumpers" in the top of the nosegear well which stop the wheels from rotatring...God I miss that sound...

Also, in the beginning, the 727's were equipped with nose gear brakes...activated when either pilot applied more than 80% pressure (B System) on the brakes upon landing...

Most operators removed these brakes for 3 reasons...#1: Unless you really screwed up, you never had to use 80% brake pressure...(the main wheel brakes are very over engineered)...#2: MEL reasons...if they were installed they had to work,,,if memory serves correct they could be deferred for 3 or 10 days, depending on the operator's OPSSPECS, and #3:..Removal of the NWB's saved about 110 lbs. in weight...Hope this helps...

Also, the brakes are powered by "B" System...

[aveng]

...activated when either pilot applied more than 80% pressure (B System) on the brakes upon landing...

I believe it was when the brake peddles were depressed greater than 50%:ok:

[DownIn3Green]

Aveng...could be, my memory is foggy, but for some reason 80% sticks in my mind, however, you are right, it is brake peddle depression, which equates to pressure applied...

We are saying the same thing, just the number is different...still miss the rubber bumper noise...happy flying if you still are, I envy you...cheers...