PPRuNe Forums - View Single Post - BA 777 on fire in Las Vegas
View Single Post
Old 7th Oct 2015, 12:15
  #585 (permalink)  
D Bru
 
Join Date: May 2010
Location: SOF BG/EU
Age: 63
Posts: 90
Likes: 0
Received 0 Likes on 0 Posts
On the question whether G-VIIO’s failed engine was covered FAA AD ‘s concerning the G

According to GE, quoted by AP on 6/10, the spool in question was amongst the first made for the specific engine type (GE90-85B) in 1995.

Now, AD 2002-04-11 not only states that it is applicable to GE90-85B engines, but specifically “to each engine of the type, regardless of whether is has been modified, altered or repaired in the area subject to the requirements of this AD.” See page 4 of this document:
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/c38ae8b2dcfa515f86256bb3006c362a/$FILE/020411.pdf

GE is also quoted to have stated yesterday about the engine fitted to G-VIIO that “this was the first engine failure of its kind, as spools could be similar in design but were not built identically.” This last part is very important, not only because it distinguishes between an earlier uncontained engine failure, which concerned a different (and btw later) version of the GE90, but also because that is exactly where in my opinion part numbers become relevant, if one talks GE90-85B.

The table on page 6 of the document referred to above, mentions the HPCR Spool stage 8-10 and indicates that “all” partnumbers are covered. So, any HPCR Spool stage 8-10 on a GE90-85B.

Given these specifics mentioned in the AD and the year of manufacture (1995) of the G-VIIO engine, it seems therefore pretty clear at least to me that this particular engine was covered by AD2002.

Now whether it was also covered by AD 2011-15-06 depends on the specific partnumbers of the failed engine of G-VIIO. This AD also applies to GE90-85B engines, but concerning the HPCR 8-10 spool, only if it would involve partnumber 1844M90G01 and 1844M90G02 (but not other builds, although of the same design). GE has denied that these parts were involved in the G-VIIO engine, so that AD 2011-15-06 would not seem applicable.
D Bru is offline