Hey
 

TURIN, dreamland Flightmech,ASFKAP read and eat them words.:D
You do write from one IP address.

It isn't shared with any other user.

Regards
Rob PPRuNE Admin

On 28 Jan 2011, at 02:12, Brigid @ PPRuNe Forums wrote:

I think this has been done to death by now, however id just to like remind everyone to be aware and double check those caps, i will be and will certainly report any missing ones to the engineers, (and i would expect them to take some action:ok:)

Rhubarb Rhubarb Rhubard

The A320 AMM states that the purpose of the valve cap is to perform both of these tasks.
that´s interesting! i haven´t found that explanation anywhere. would you care to give your source in the AMM?ATA etc etc

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.

Hows that Wirelock??

What are you saying, that we are all the same person or using the same computer to post, if so, you might want to go back to computer 101 or security guard recurrent training.

Found this Here

Of course, this firm have an agenda, sell you a sophisticated valve cap, but it does clearly state......


And also here National-fleet.co.uk/authorisations/TyreTraining.



Ooh! And here...

Michelin.co.uk/tyres/learn-share/care-guide/ten-tyre-care-tips


I'll stick with what I was taught twentymumblemumble years ago. :ok:

Since it's a slow night on the telly, I found myself irresistibly drawn all the way down this thread, and have been amazed.

Not so much by the sniping between those who think they know and those who think they know better, because that's normal for pprune (and most forums (fora?))....

….but the thread has gone an amazing distance without anyone pointing out the actual frame of reference for what may be deferred and what not (whether it's about valve caps or anything else).
I hasten to point out that this reference is only applicable to those aircraft subject to EC2042/2003 (i.e. aircraft under EASA regulations). Other types of operation may well have similar or different requirements, but the following is good for EC registered aircraft...

M.A.403 Aircraft defects
(a) Any aircraft defect that hazards seriously the flight safety shall be rectified before further flight.
(b) Only the authorised certifying staff, according to points M.A.801(b)1, M.A.801(b)2, M.A.801(c), M.A.801(d) or Annex II (Part-145) can
decide, using M.A.401 maintenance data, whether an aircraft defect hazards seriously the flight safety and therefore decide when and which
rectification action shall be taken before further flight and which defect rectification can be deferred. However, this does not apply when:

1. the approved minimum equipment list as mandated by the competent authority is used by the pilot; or,
2. aircraft defects are defined as being acceptable by the competent authority.
(c) Any aircraft defect that would not hazard seriously the flight safety shall be rectified as soon as practicable, after the date the aircraft defect was first identified and within any limits specified in the maintenance data.
(d) Any defect not rectified before flight shall be recorded in the M.A.305 aircraft maintenance record system or M.A.306 operator's technical log system as applicable.

Once you get your head around this it's very straightforward –
If you have an MEL and it's listed, you can defer it.
If you have an MEL and it's not listed, go to the approved data and check if it should be there.... if so, install it or stay on the ground.
If you don't have an MEL and the Manual says it should be installed – install it or stay on the ground.

Palatialvilla has said the best words on this so far, inasmuch as you may be able to get an NTO from QA to deviate from procedures, after all, your MEL was written by your Company. (Note: MEL, not MMEL).

All this stuff about whether it's a seal or a dust cap isn't worth squit in EASAland, neither is how much judgement is good for the soul – wake up guys & gals, you ain't allowed to use judgement these days, 'cos EASA says so.....

Now, whether you go with what you're actually allowed to do or whether you use that hard-earned judgement is up to you, but at the court of enquiry they won't care whether the rules are sensible or practical, just whether or not you followed them.... :=

...and it's taken me over 40 years to get my head around that bit...... funny old world :ok:

Turin,

It should be interesting to see how many postcards you get??

The valve core is the primary, as has been said, and then there is an indication within the valve cap that will tell you that the primary core is leaking before very much air/nitrogen escapes.

Send Turin your postcards!!

Speedbird 48.

Coriolis, excellent post.

As you say, it takes many many years to get your head around it.
I haven't yet, but I'm trying. :ok:

Speedbird48

I have had too much cider tonight so I haven't a clue what you are on about.

[QUOTE]The valve core is the primary....[QUOTE]

So YOU say (and admitedly one ore two others). However, what is this indication within the valve cap that will tell you that the primary core is leaking? I am confused, maybe it's the Scotch that followed the Cider.

What we need is a reference point, preferably one easier and more practical to use than the one offered by Coriolis. I have found several as shown in my previous post but none with the clout of an AMM or an Airworthiness Notice for example.

I'll accept anything as fact once proof is given. So far all we have is a group of anonymous posts arguing that black is white.






I think it's black by the way. :\

no it's grey!:eek:

Valve caps are Yellow..:}

Put two back on the 752 nosewheels I fitted and inflated, this evening.. Oh, I put two back on the wheels I deflated to remove!!:E

Simples..

" The valve core is the primary, as has been said, and [B]then there is an indication within the valve cap that will tell you that the primary core is leaking before very much air/nitrogen escapes."[/B


Which usually comes in the form of a "psst" sound when you remove the valve cap....strangely enough.

However, you may wish to drop HM Gov't a line and politely inform them that, for many years, the training syllabus has been incorrect and that myself, and many others, have been labouring under a misconception as to what is defined as the primary seal....

I have those leak indicating valve caps installed on my car. They are great as they also reinflate the tyres automatically when they sense (and indicate) a leak, as well as sending a message, via the ARINC 429 bus I installed at the same time as the caps, to the CMC mounted in my dashboard to not only notify me of the leak, but also of any impending leaks in the next 48 hour period.

Would they be the same caps you are talking about Speedy...

If the cap was the primary seal the gas would all escape when you removed it. As you say, and correctly found from the OEM, it is a secondary seal whose main purpose is actually to keep dirt out not gas in.

Re MEL I was always taught if it's an airworthiness item and it's not in the MEL you don't fly if it's not there and working. Many interior items fall into the 'non airworthiness' classification hence HIL items, and I would interpret valve caps the same way.

I've never known an engineer who didn't have a bag full of them anyway, or at least a full set on his car ;)

Well, it would if the secondary seal, known as a valve, wasn't fitted or had failed.

I don't know any who have them on their car. Getting the wheel rebalanced just isn't worth the effort.

Collected my fair share over the years from the runway taxiways and aprons, always been taught that a valve cap = Dust cap if valve is exposed brake dust grime can build up, upon inflation this may contaminate the valve core and stop it seating properly causing it to leak.

The other valve caps I know of are the ones held on to a valve spring by collets which secure the valves in cylinder heads if they let go you are in a spot of bother :uhoh:

I also have found many over the years and recently found one in a tyre prior to commencing my pushback while doing my last minute safety check.


Problem is the engineers do not tighten them up correctly,:ugh: often just using their fingers , i always remind them if i see wheels being worked on of the dangers of FOD caused by lost caps.

Oh dear. Deja vu all over again. :hmm:

Is it just me or does anyone else think that "the hitcher" has found a new identity?