CDL time limitations

[carlyle]

When looking through the items in our companies CDL (Configuration Deviation List), I cannot find any reference to time limitations, unlike in the MEL where you have the A, B, C or D categories.
Can someone kindly enlighten me how time limits are usually applied to CDL items?
Many thanks

[matkat]

CDL items are not deemed to be airworthy issues therefore can be repaired when convient.

[Vortechs Jenerator]

matkat, he doesn't mean cabin defect log by CDL whish is what you are thinking (I think) the CDL he means can be airworthy, Config Devialtion.

Some companies merge the CDL into the MEL so that if you get an Item that is allowed to be U/S and it has a maintenance action (little m in brackets), say locking a valve open, popping a CB and putting an inop sticker on it - that is the CDL part.

Some companies still have the CDL seperate from the MEL

So I think the MEL time limits are still the controlling aspect. Can you give me an example of a CDL item that is not MEL controlled?

[itwilldoatrip]

The CDL is airworthy indicated items that can be missing or partially missing (thinking of panels and say seals here). In our company these are time lifed dependant on the severity and may be resticted in number allowed missing or damaged (ie No of seals missing per wing).
Regarding inoping a valve and putting a sticker on the CB that would be part of the MEL M proceedure and considered as having complied with the MEL. By the way can't think of many instances of popping a CB as nowadays with the electronics we normally get the AV's to put a dummy plug in on the valve plug to short it out and fool the system which again most MEL M proceedures indicate.

[Vortechs Jenerator]

Not all aircraft were built "Nowadays" mate, I stand by what I said about the CDL - in the company I'm at at this moment

[bvcu]

Still MEL procedures that require c/b pull and collar on both 777 and 330. both modern in production a/c.

[Mr.Brown]

Dispatch deviation, config deviation, whatever its called these days.
Alot if the items will have no time limit, as it just gives the requirements for operating without ie extra fuel burn etc....

[anawanahuanana]

I guess it also depends on how the Company specific CDL was written and how the Airworthiness Authority of the country wanted it before they would approve it. The company I work for operates 2 distinct types. For one, the CDLs are unlimited as far as time is concerned. For the other however, CDL items are limited to 180 days.

[itwilldoatrip]

Not all aircraft were built "Nowadays" mate, I stand by what I said about the CDL - in the company I'm at at this moment

Sorry I am working on up to date new generation fly by wire A/C.

[carlyle]

OK, so essentially it is up to the company to impose it´s own time limits on CDL items as it deems necessary, within reason I would say.
Great, thanks for your replies.

[spannersatcx]

Our CDL has time limits the same as the MEL cat C or D 10 or 60 days, however another operator we handle with the same type doesn't have any time limits.

[Vortechs Jenerator]

the company I'm contracting in at the moment is not UK based and have some "special" ideas...

Taken from http://www.caa.co.uk/docs/33/CAP549.PDF

NOTE: Configuration Deviation Lists (CDL) or their equivalent, are not a part of the
MMEL and are not dealt with in this CAP. CDLs are used to identify any
external components of an aircraft type which may be missing for dispatch,
where necessary, they will provide any associated information on
performance corrections for such cases (e.g. missing landing gear doors, flap
actuator fairings, etc.). Where dispatch with such items missing is approved,
the CDL may be published as part of the CAA/JAA approved Flight Manual.

Hope that helps a bit

[Piper19]

Very simple, CDL (config deviation list) has a default time limit of 120 DAYS, unless otherwise stated in another reference (AMM, SRM, tech note, ...). You as engineer can deviate from the default 120d by saying for example "to be carried out next A-check" or "next hangar input" or something like that, where in the MEL, you cannot deviate from the time limit. Be aware for the time limits in the AMM, many people forget these.
It can be that the default value differs from company to company, but this can be found in the CAME or MOE, check your quality dept.

[hannibal lector]

I think you guys have it wrong. SOOO HARD. A CDL is applied for as long as your company book states. It's only impact on the Aircraft is Fuel Burn and weight penalties. Basically if you can afford the extra fuel and weight penalties then who cares

[Exup]

Have to agree with Hannibal, just checked our company's CDL no time limits given just performance restrictions that must be adhered to. There is the obviuos extra fuel burn so if you can afford it carry on.

[spannersatKL]

CDL items don't need a time limit, remember they may have an operational impact for example higher fuel burn but no impact on 'safety' where as MEL items usually have an impact on safety.

By deferring IAW the MEL you are using up the redundancy on the aircraft systems and hence will be operating nearer to the 'edge' as it were. Its not UNSAFE its within the margin of safety (per Part 25.1309) just not as safe... a Systematic Safety assessment by statistical analysis will reveal the limitation that will need to be applied, for example CAT A, B, C or D.

For further reading have a look at the book 'Systematic Safety' which explains how this is achieved; and also why 'flogging' the item off at the end of the time limitation and then deferring the item at the next station because your company has not got the spare can lead you to skating on very thin ice!

[Piper19]

There is no time limit in the CDL, because it's a default. This can be found in your maintenance exposition manual as I said before, thus it depends on your company. Because the default differs from company and can be deviated from by the mechanic, it cannot be written in the CDL itself. It is a large time limit that offers planning/engineering dept plenty of time to plan it in sheduled maintenance checks.
And indeed the only possible restrictions you can see as mechanic are weight penalty or fuel burn.

[glob]

CDL

CDL stands for component deviation list which releases the flt if a panel needs to be removed due to damage, Its a part of the MEL.

For example if you have a damage on the flaps fairing were you want to dispatch the flt without the fairing you have to ref to the CDL were it clearly tell you about the procedure & the fuel restriction (O)+(M)