ADD's
Someone posed a very interesting question to me a few days ago regarding the extensions given by local regulatory authorities to operators to Authorised Deferred Defects:
If Boeing or Airbus says that a particular defect must be fixed within a certain time according to the MMEL, shouldn't be fixed within that time?What authority or experience does the local CAA or DCA have to extend the stipulated period?
Now I asked around and didn't quite get a satisfactory answer. Engineers say that the CAA can do this as they may have had a lot of experience with a particular type or defect such that they know that safety won't be compromised by the extension. Some even told me that a perticular authority in the middle east says that " Extending the period is a matter of national security, as keeping a national airline from operating is a security risk"!
What I would like to know is whether the manufacturers support these extensions, and if so where is this documented, because -to be simplistic about it- these regulatory authorities have basically made themselves test pilots and design engineers by allowing these extensions. If Boeing or Airbus didn't think the time limits were pertinent, they wouldn,t have put them in the MMEL's in the first place.
Thanks to all in anticipation.