Valve cap missing
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PPRuNe supporter
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From: Planet Earth
Thanks to all the posters, to be clear, it involved one of the main landing gear tyres, I told them I wanted it installed, it was from our maintenance base and the base for 25 similar aircraft. After another 10 minutes one was found and installed. I did t have a clue whether there was a safety issue involved. Iwas sure the engineer was wrong, but apparently I was wrong. 
Cheers D.L.
Cheers D.L.
Thought police antagonist
Joined: Jul 2003
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From: Where I always have been...firmly in the real world
Fascinating little thread about..... " the primary and secondary functions of the dust cap sealing device "...
....
The really worrying bit is the lack of acumen shown by said line engineers however !
....The really worrying bit is the lack of acumen shown by said line engineers however !
Joined: Mar 2005
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From: England
Dream Land was right to insist, the valve cap is there to prevent leaks and dirt ingress.
From the AMM wheel inspection A320
I read from his original post that this was deferred as an ADD and Dream Land asked the engineers at his main base to sort it when he got there. Exactly the right thing to do in my opinion.
From the AMM wheel inspection A320
4. Procedure
NOTE: The data given is for bias and radial tires and for all Airline Operators.
Subtask 32-41-00-210-070
A. Visual Inspection of the Wheels
(1) On each main gear wheel, examine the drive shroud of the tachometer.
(2) Make sure that there are no cracks on the wheel rims.
(3) Make sure that there are no leaks on the valves.
(4) Make sure that the valve thread is not damaged. Fully tighten the valve cap which seals the valve from dirt and leaks
NOTE: The data given is for bias and radial tires and for all Airline Operators.
Subtask 32-41-00-210-070
A. Visual Inspection of the Wheels
(1) On each main gear wheel, examine the drive shroud of the tachometer.
(2) Make sure that there are no cracks on the wheel rims.
(3) Make sure that there are no leaks on the valves.
(4) Make sure that the valve thread is not damaged. Fully tighten the valve cap which seals the valve from dirt and leaks
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From: EGGW
The Hitcher
The difference between your bike or car whatever, is that the cap on an aircraft wheel is made of metal, with a seal and can be tightened with a spanner (wrench to our American cousins).
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From: Where I always have been...firmly in the real world
Hitcher,
Your first post was fair enough...NO problem with that and as you admit, you've never been near a crewroom, ramp, line, hangar or flight deck etc in your life otherwise you would be aware of the capacity of engineers and F/D to " discuss at length" as they say to prove a point...sometimes these, ahem . discussions can get rather "warm" and even, possibly " a little animated " .
This one hasn't...
Your second however, suggests you need to carry out a functional check on the location of your larynx.......
Your first post was fair enough...NO problem with that and as you admit, you've never been near a crewroom, ramp, line, hangar or flight deck etc in your life otherwise you would be aware of the capacity of engineers and F/D to " discuss at length" as they say to prove a point...sometimes these, ahem . discussions can get rather "warm" and even, possibly " a little animated " .
This one hasn't...
Your second however, suggests you need to carry out a functional check on the location of your larynx.......
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From: moving around
Schrader valve - Wikipedia, the free encyclopedia
so this type of valve is a schrader valve. although wikipedia it does give the function of the cap. it is NOT a secondary or primary seal of any sort. it is only to prevent dirt entering the valve
so this type of valve is a schrader valve. although wikipedia it does give the function of the cap. it is NOT a secondary or primary seal of any sort. it is only to prevent dirt entering the valve
Thought police antagonist
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From: Where I always have been...firmly in the real world
sycamore,
Fair point...or just fishing....or just being holier than than thou ?
Rhetorical question.....how many drivers would notice one was missing...on a wet / cold night at 00 silly hrs doing a walk round?.
Fair point...or just fishing....or just being holier than than thou ?
Rhetorical question.....how many drivers would notice one was missing...on a wet / cold night at 00 silly hrs doing a walk round?.
Joined: Mar 2005
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From: England
The Hitcher said -
Anyway, back to valve caps. Anyone found any legal doc for the Airbus that says you can defer a missing cap?
Get over yourself you pompous berk ,it doesnt take a brain surgeon to spot fluid peeing out of a wheel however you lot of overpaid prima donnas missed it and a "well meaning amatuer" spotted it and possibly saved a lot of lives.....idiot
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From: Newcastle-upon-Tyne
With the plastic bicycle or car type cap, agreed - they do not act as a secondary seal, but aircrat ones do! As said earlier, they are designed for the function of keeping air in the tyre in the event of primary seal failure. (Metal + torque setting... usually 6lb/in, ie. calibrated-finger tight).
As a ramp tramp (semi-retired) I would think twice about grounding an aircraft with a missing valve cap... just imagine trying to explain that one to the CEO.. but for the jockey to put in an ADD, no problem. It'll get done ASAP.
In Hitchers defence, flight safety is everyone's problem, so full credit for spotting the faults. As a security guard, his responsibility will cover the ramp and the aircraft on it, so I can see why he is close to the aircraft. He did not say he interfered with the aeroplane.
Can we just all get along please?
As a ramp tramp (semi-retired) I would think twice about grounding an aircraft with a missing valve cap... just imagine trying to explain that one to the CEO.. but for the jockey to put in an ADD, no problem. It'll get done ASAP.
In Hitchers defence, flight safety is everyone's problem, so full credit for spotting the faults. As a security guard, his responsibility will cover the ramp and the aircraft on it, so I can see why he is close to the aircraft. He did not say he interfered with the aeroplane.
Can we just all get along please?
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From: UK
And how many `gingerbeers` would check the tyre pressure before replacing a missing valve cap ??
Tech log certified as such too.
All this confusion between bicycle tyres, schraeder valves and the humble aircraft tyre.
Bicycle tyre dust cap, plastic, cheap, keeps the dirt out and protects the thread. Same on my car.
Someone somewhere must have it in writing as it was drummed into us for years that the Valve Cap (on an aircraft wheel) is the Primary seal.
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From: east ESSEX
K-n-c,Turin, et al, I know it may have been a little tongue-in-cheek,about checking the tyre pressure as well; however what you do on your car is one thing,aircraft are widely different,and wheels and tyres suffer more than your average jalopy .The cap is there as a cover to prevent contamination of the sealing mechanism,from heat, dust, liquids,etc and to act as a second seal if the valve itself fails.If it isn`t there,it should be replaced,not by one you have lying in a tool box/pocket/ashtray,but by a new/clean one.Not only that but any `sensible` engineer should inspect the valve to see if it has failed,or is loose/damaged,and check the tyre pressure as a matter of course,as the tyre may have a failing valve.Consider also the fact that the valve cap has a certain mass/weight,not a lot, but on take-off and landing it can be accelerated to a speed of up to 300 ft/sec on large aircraft.It`s energy probaly won`t punch a hole in the airframe,but it may cut wiring or a hose,or jam in a brake caliper.And ,yes,I`ve done my walkrounds at oo.oo o`clock,from -30 to +40 wet or not,but prefer `normal` working hours now !!