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747SUD And Other Emergency AD

Posted: Sat Feb 19, 2005 4:31 am
by meister808
Turns out that the upper deck on some classics has been having trouble. Not really a deal, but thought y'all might find it interesting, especially considering the fact that the AD was issued yesterday:

http://www.airweb.faa.gov/Regulatory...1963D86256FAC00533907?OpenDocument

And to quell the inevitable, no, this does not mean that the 747 is unsafe and/or should be grounded. ADs happen to every aircraft that has ever been built.

It is interesting, however, that they want this inspected once every 25 cycles. Thats pretty often.

-Meister

RE: 747SUD And Other Emergency AD

Posted: Sat Feb 19, 2005 5:54 am
by dl757md
Quoting Meister808 (reply 0):
It is interesting, however, that they want this inspected once every 25 cycles. Thats pretty often.


Not really. 25 cycles on a 747 can be more than 200 hrs. Not a lot when you consider 100 hr inspection on GA aircraft. Also the repetitive inspections (25 cycle) are no longer needed after an HFEC(High Frequency Eddy Current) inspection. The reason for the high frequency of the visual inspetions is that your are looking for EXTERNAL signs of already existing INTERNAL damage. This damage may take hundreds or thousands of hours to show up externally. The HFEC is a non-destructive test that show all internal damage and a successful HFEC inspection insures that there is no damage at all, external or internal.

Dl757Md

RE: 747SUD And Other Emergency AD

Posted: Sat Feb 19, 2005 6:18 am
by meister808
Fair enough. I am assuming most of the operators of these aircraft are going to opt to just go ahead and do the HFEC inspection, then? Is that an expensive one?

-Meister

RE: 747SUD And Other Emergency AD

Posted: Sat Feb 19, 2005 6:26 am
by B747FE
Interesting info.

I think most of the operators will go directly for the HFEC in order to avoid the repetitive inspections.
In our fleet we made the mod specified as a terminating action.

Quoting Dl757Md (reply 1):
Not really. 25 cycles on a 747 can be more than 200 hrs.


Yes, in a -200/300 series.
The SUD mod was also available for -100B SR.
25 cycles for us means 50 to 60 flight hours, in one week.

Regards,
B747FE.

RE: 747SUD And Other Emergency AD

Posted: Sat Feb 19, 2005 7:14 am
by dl757md
Quoting Meister808 (reply 2):
Is that an expensive one?


If the operator has their own equipment and personnel it shouldn't be too bad. If they have to contract it out then it could get expensive. I have no idea how long it would take as I'm not sure of the size of the area or the exact requirements for the inspection.

Dl757Md