All this metallurgy discussion is fine, but John Sharp's article disputing Bailey's report is interesting to me. He disputes the "engine overheating" theory, fine. He then admits the the prop only sheared off after the crew cut off the fuel to the engine. Now maybe they didn't cut off the fuel due to engine overheating, but they certainly did cut off the fuel. Why? According to the PAN call: "uncommanded engine operations and then our propeller has just sheared off."

So something, observable to the pilots, happened prior to the prop shear, which was enough to prompt a shutdown. Were these "uncommanded engine operations" the cause of the prop shear? Or perhaps merely a symptom of the prop partially shearing prior to completely shearing? Is the gearbox still ok?

It was noticeable, and worsening, vibration which motivated the crew to shutdown #2. It was during this sequence the separation occurred.

Per Investigation: AO-2017-032 - In-flight propeller malfunction involving SAAB 340 VH-NRX, 19 km SW of Sydney Airport, NSW, on 17 March 2017

And while I'm sure the PGB will get a thorough teardown inspection, I don't see anything at this point that would be distressed, other than possible bearing brinelling.

What would happen if it was feathered while still (un-commanded possibly) producing a decent amount of power ?

It would cause an over-torque (or near so) condition, probably requiring a PGB teardown inspection.

It may be the light, but if you look at this photo, there seems to be a surprising number of nuts missing from the (presumably) propeller hub studs. There is in all the pixel fuzz apparently one remaining at around 10 o'clock as displayed. Odd!

http://www.atsb.gov.au/media/5772523/saab340_prop.jpg

Andy_RR
This was a topic of discussion a couple of pages back when the prop was found!

Ah, yes. Sorry Capt. I got bored hammering through this and the other thread before posting - big mistake!

My thoughts follow Leadie's conspiracy theories though. Why would you publish such a photo in a prelim report when someone official would presumably have officially documented the entire recovery process - you know, as found, turned over, dirt and grass brushed away etc. The guys there seem well equipped with cameras but no sign of any spanners in hand.

It seems strange that you'd publish such a trophy hunt photo without at least explanatory notes regarding the missing nuts, even if to remove the potential for conspiracy theories to hatch...

They are clearly unaware of Jonkster's Second Thereom.

Jonkster's Second Thereom: when calculating the likelihood of people making up a conspiracy theory to fit the evidence, you will always underestimate it.
Even when you take into account Jonkster's Second Thereom.

How many similar pictures have you seen published by ATSB, jonkster?

Post one link to one picture with ATSB staff holding a piece of aircraft, which piece may be related to an incident, published by the ATSB.

Just one link.

If those pictures were taken and made available to someone by the ATSB, you don't have to bother with 'conspiracy theories'. The organisation would, in that case, evidently be a complete basket case.

Sounds as though it's not only Rex's Saab missing a few vital bits.:E

Final report is out

(my post count too low to post link)