A321 NEO PW1100 case crack on DEP from Brussels.
 

Turkish Airlines A321 NEO PW1100 gearbox case crack and oil leakage on DEP from Brussels. Ac returned to Brussels for engine change.

https://cimg1.ibsrv.net/gimg/pprune....76a1b4e1be.jpg

Was an accessory gearbox according to this:

https://aviation-safety.net/wikibase/wiki.php?id=218702

Gearbox/Accessory Gearbox is the same thing. The engine gearbox is there to provide drive for the accessories - oil pump, fuel systems, electrical systems etc.

Another PW1100 problem. In my experience cracked gearboxes like this are very rare especially so early on.

Gearbox case is the operative term here. jeez

All the same, a very unusual looking crack in a new engine accessory gearbox case.

Doesnt look like a crack, but more like tear failure?

Great! Another round of inspections.
That's a hell of a failure. Wonder how long it takes to produce a full suite of new gearbox casings for all the PW1000s out there?

What did John Glenn say about "sitting on top of 2 million parts all bought from the low bidder" ?

Very good point...

The casting in that region looks very strange - the surface faceted as though the metal was applied with a trowel.

Closeup of break...(and limits of break)

https://cimg8.ibsrv.net/gimg/pprune....78bb64b361.jpg

Avio Aero gearbox:
https://cimg1.ibsrv.net/gimg/pprune....f5e68cfb75.png

I was thinking the same myself, maybe the lighting but it doesn't give the impression of a beautifully finished component.

Casting or forging ?

Aluminum casting.

One part shows a manufactured date of 10.05.2017

I don't disagree that it appears to be the Accessory Gearbox, but on the PW1100 don't they have a separate 'gearbox' for the geared fan?
I'm not very familiar with the PW1100 architecture but I'd assumed they they had two gearboxes - the accessory gearbox, driven off the high spool, and a fan gearbox driven from the low spool?

PW1100G fan gearbox (3:1 gearing):
https://cimg3.ibsrv.net/gimg/pprune....1240e50306.jpg

It looks like the lighting and a degree of tonal separation (posterization) in the heavily compressed image are exaggerating the appearance of surface unevenness.

The gearbox is an aluminum sand casting, not an investment casting where surfaces as cast are much smoother. Almost all accessory gear boxes are sand cast either made out of aluminum or magnesium and are not polished to make them look good. Nothing new about the way the surface looks except for the crack.

As Dave noted, the planetary gear assembly is directly on the shaft...the fan is connected to the outer ring, and the shaft through the center...I believe the planetary gear assembly is made by Kawasaki...


https://cimg1.ibsrv.net/gimg/pprune....94a5e20d5c.jpg

C'mon guys, it's a straightforward Epicyclic sun & planet gear train, been used for all sorts of uses for about 100 years or more. For Pratt & Whitney, the good old PT6 turboprop, like most turboprops, had its reduction gearing using the same concept, though that had three intermediate carrier gears instead of five.

Also, where is the subject gearbox in this thread title?

Can someone tell me which way the Fan turns, the LPC turns, the HPC turns, the HPT turns and the LPT turns ? I'm getting mixed up with two rotor system and a fan as a separate rotor?

Would there normally be sufficient stress on the casing to cause such a fracture, unless it had a manufacturing fault?

Surely the casing is a container, rather than a load-bearing component.