notbluejet
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A320 Nose Strut Extension Lenght

Thu May 19, 2005 1:48 am

I was wondering if anyone knows the extension lenght of an a320 nose gear strut. From full load to none.. as far as the link allows....

Thank you
 
320tech
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RE: A320 Nose Strut Extension Lenght

Thu May 19, 2005 6:38 am

Well, it depends on temperature, load, and the strut charge. The normal extension is about 5". Full extension is quite long, but don't know the number off hand.
The primary function of the design engineer is to make things difficult for the manufacturer and impossible for the AME.
 
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HAWK21M
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RE: A320 Nose Strut Extension Lenght

Thu May 19, 2005 12:53 pm

Quoting 320tech (Reply 1):
The normal extension is about 5".

Are you refering to the Chrome exposed surface of the Oleo.
Or is there a ref Measurement point aka the B737s.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
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IFixPlanes
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RE: A320 Nose Strut Extension Lenght

Thu May 19, 2005 3:21 pm

Like 320tech wrote before it depends on temperature, load, and the strut charge.
Here is a chart out of the maintenance manual:


HIH

Ingo
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HAWK21M
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RE: A320 Nose Strut Extension Lenght

Thu May 19, 2005 7:48 pm

Thanks for the chart.
Can the A320 Oleos be Charged on Jacks & Lowered to confirm pressure/Extension chart as in B737s.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
320tech
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RE: A320 Nose Strut Extension Lenght

Fri May 20, 2005 12:36 pm

Yes, it can be done on or off jacks.
The primary function of the design engineer is to make things difficult for the manufacturer and impossible for the AME.
 
Matt72033
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RE: A320 Nose Strut Extension Lenght

Fri May 20, 2005 3:09 pm

is it just me or does the 320 family's nose gear have a slight forward angle? could just be my eyes playing tricks on me!?!?!? lol
 
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HAWK21M
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RE: A320 Nose Strut Extension Lenght

Fri May 20, 2005 5:14 pm

Any Good pics of the A320 NLG on Jacks.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
glidepath73
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RE: A320 Nose Strut Extension Lenght

Thu May 26, 2005 5:17 am

Matt72033,

your right. The nose gear is bending a bit forward. It even seems that the main landing gear seems to bend slightly to the back. Check the newest A320 pics in the database and you can see it clearly.

What was the reason for those angles at the 320 series landing gears?

Regards,
Patrick
Aviation! That rocks...
 
WindowSeat
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RE: A320 Nose Strut Extension Lenght

Wed Jun 01, 2005 3:57 am

Quoting Notbluejet (Thread starter):
Well, it depends on temperature, load, and the strut charge.

What is a strut charge?

cheers
I'm all in favour of keeping dangerous weapons out of the hands of fools. Let's start with keyboards.
 
320tech
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RE: A320 Nose Strut Extension Lenght

Wed Jun 01, 2005 6:09 am

What is a strut charge?

In airliners, the landing gear shock strut (aka oleo, gear leg, etc) is filled with hydraulic fluid (H-515, MIL-H-5606, AeroShell Landing Gear Fluid, "red stuff"), then topped off with nitrogen.

The fluid provides the main shock absorbing function on landing, while the nitrogen smoothes out lesser bumps, eg during taxi.

To fill it, the strut is compressed (we use a platform that can be pumped up to three feet or so), then filled with hydraulic fluid. The strut is then "blown down" using about 50 psi of nitrogen. Once it's fully extended, the strut is charged with nitrogen - around 1200 psi or so.

The process is a little more involved than what I've described, but it gives you the idea, I hope.

The strut charge, then, is the pressure of nitrogen in the strut. It's supposed to correspond to the strut extension. If extension is too low, either you're low on fluid or low on nitrogen. If it's too high, you've got too much nitrogen (can't really have too much hydraulic fluid).

And for the other A320 AME's, yes, I know, upper and lower chambers, etc, but just trying to keep it simple.
The primary function of the design engineer is to make things difficult for the manufacturer and impossible for the AME.
 
WindowSeat
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RE: A320 Nose Strut Extension Lenght

Wed Jun 01, 2005 7:56 am

Quoting 320tech (Reply 10):

So, in short they are sort of pressurized chambers filled with nitrogen and then hydraulic fluid?

When the aircraft touches down, if all of the fluid takes the force only relying on its ability to compress or absorb the shock would that not pose a problem? Does it have like an overflow system which combines the viscous nature of the fluid to slow the rate of overflow, thus absorbing the force and also creating room for the strut to compress into the chamber resulting in absorbing of more force?

OK, did y'all get that or am I looking stupid right about now? Not sure if I am explaining this right? I need a whiteboard...

cheers
I'm all in favour of keeping dangerous weapons out of the hands of fools. Let's start with keyboards.
 
FredT
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RE: A320 Nose Strut Extension Lenght

Wed Jun 01, 2005 6:10 pm

The fluid does not compress to any significant degree. That's one of the main criteria for a hydraulic fluid to be a good hydraulic fluid. It flows through valves to create a resistance as the strut is compressed, just as in any hydraulic damper/shock absorber.

The fluid is damping, the nitrogen is the "spring".

Cheers,
Fred
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
320tech
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RE: A320 Nose Strut Extension Lenght

Thu Jun 02, 2005 1:17 pm

they are sort of pressurized chambers filled with nitrogen and then hydraulic fluid

Other way round, really.

if all of the fluid takes the force only relying on its ability to compress or absorb the shock would that not pose a problem

As FredT says, the fluid doesn't compress. The fluid is forced through an orifice which decreases in size as the gear is compressed. This provides the shock absorbing action.
The primary function of the design engineer is to make things difficult for the manufacturer and impossible for the AME.
 
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HAWK21M
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RE: A320 Nose Strut Extension Lenght

Thu Jun 02, 2005 6:23 pm

Quoting 320tech (Reply 13):
As FredT says, the fluid doesn't compress. The fluid is forced through an orifice which decreases in size as the gear is compressed. This provides the shock absorbing action.

Also a snubber valve in the strut to reduce Oleo extension speed in Air.
regds
MEL
I may not win often, but I damn well never lose!!! ;)

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