System deactivation
 

Hi,

I have some hard talks with our tech dep regarding the deactivation of different system on the plane. The question is how your company deactivate a sys which it doesn't need ? For instance my company just pull the CB, guard it and label it "INOP" but they do not make any teh log entry. I personally think it that apart from the procedure described above there should be an entry into the teh log. Any comment?

danil

Danil,

your company obviously likes to make every flight - a flight of discovery - for the pilots. Tech log entry quoting the MEL/CDL would be the minmum, also raising an PADD (Performance Defect).

Brgd's

N1 Vibes

A system that is no longer fitted/needed/required wouldn't need an MEL quote as it probably won't be in there any more. Normally when the system(s) are first removed a DD may be raised abut also a NTC informing all crews. After a certain period this may be removed as the crews will of been made aware by crew notices, refresher training etc etc.

I also interpreted your Q as a deactivation following a defect, as "N1 Vibes" did, and thus totally agree with his response.

You are, from your response "danil", referring to a deactivation as a total removal of the specific system, a different matter altogether!!

Cheers, FD :confused:

Danil,

You should read the MM (or system discription) before pulling a CB, as it does not always shut a system down. Some systems require electrical power to shut them down. When you pull the CB it removes the electrical power and make the system powered again.

Sorry for being not specific. The issue is actually the deactivation of the airstair of a 737. The airstair works just OK but the company wants not to use it. The technicians just pulled the cb's and labeled them, along with all the switches associated with it, inop having no log entry. And the airstair is not the only one system. We got the in-flight entertainment in the same situation.
I have checked the AMM but I fond no reference to this procedure. I believe this procedure should be in MOE but it is not there. Anyway, I personally think that it should be some kind of entry into the teh log saying the sys is deactivated and specifying which CB's are pulled along with required labeling.

danil

deactivation should be recorded as a ntc .colour coded cb collars depending on the deactivation.
red-mel/cdl applied
blue/black permanently deactivated system.
airstairs are a great deal of weight and fuel burn to be lugging around if not reqd,why not remove them completely?

The only problem was on the first departure after delivery/deactivation couldn't get the fwd pax door open light out, pulled to many CB's. Something about lights.:ugh:

I have noticed on the 737 MMEL/MEL on the "definitions", item 17, that along with de definition of the deactivated item there is a requirement for the operator to develop a procedure to deactivate a system.
"An acceptable method of securing or deactivating will be established by the operator"
So whatever the method would be it should be accepted by the CAA. Being a procedure it should be written in a manual therefore controlled by the quality department. Now, the procedure would vary along the world but as long as it has been accepted by CAA it will be OK (like ASFKAP company did)

Considering all the inputs you had I think the following would be the correct way to proceed with a deactivation:
-an entry should be made into the tech log. Most common procedure would be to describe de sys deactivated along with any MEL (O) procedures into a "Briefing Card" or something similar not in the DD.

• CB's pulled and guarded with color coded collars as chemical allii said (i did not now about the color code)
• Pilots informed through company communication system (pilots brief, pilot notices, company notams, etc)
• Leasor informed - if required

Thanks a lot,

Danil

Sorry I have to disagree. If you carry out any work on any aircraft whether maintenance or operational you should always carry out an Techlog entry (or work card if its on pre-acceptance check)

There has to be some point of reference for the de-activation. You should also be doing it i.a.w some type of authorisation from your company tech or quality department which will refer to a specfic laid down procedure from Boeing (or similar).

most, if not all system deativations are covered by company modifications, and thus there is no need for a tech log entry.

.... are covered by company modifications, and thus there is no need for a tech log entry.

.. except for the log entry certifying for the modification per approved design data issued by the company tech services folk.

Main point is that there needs to be something written down somewhere for configuration control purposes .. otherwise the records are anarchy.

not if the aircraft are delivered to the company and then modified. In this case the company can add a page in its OM-B how is the configuration of its aircraft.

If you wanted to track all modification you made on your airplane, your tech log would be full!

Dani

Dani,

We are looking at two different needs ...

The engineering side of airworthiness requires great detail in aircraft and configuration history. If you don't have it .. then best of luck if you ever seek to transfer Registers in the future.

I think that you are concerned more with the implications to crew ?

A company modification is just that. It’s simply a mod that’s been designed in house and approved by the relevant Quality/Tech department. At some point it then has to be applied to an aircraft for certification and record purposes (Task card or Tlog)

Depends where the de-activication took place ! If on a check no Tlog entry would be required as it would be covered by a task card (which in essence is an extension of the Tlog) but on a line station it probabally would be...:)


This is a very illuminating thread :eek:

If you just add a page in the aircraft OM-B how is the CRS for the work carried out issued?

If you carry out any modification, rectification or work on any aircraft you have to raise an entry somewhere for certification purposes. This work has to be carried out i.a.w with all known procedures (Company, MM etc) then a CRS is issued by an appropriate approved engineer. This work can be on a task/work card if on base check, or if on an outstation/line and the only access is the Tlog it goes in there. Only then when the company Tech records has the information that the mod has be carried out does it go in the OM-B (and not before)

And yes if there a lot of modifications needed to bring the aircraft up to company requirements it’s a lot of paperwork !!! :)