SSPhoenix From United Kingdom, joined Aug 2010, 96 posts, RR: 0 Posted (4 years 8 months 1 week 6 days 21 hours ago) and read 27583 times:
Flight has just reported that the TEST Trent 1000 engine based at the Rolls Royce Derby test-bed has suffered an uncontained failure that preliminary analysis points towards the failed component originating from the IP Turbine.
Anyone out there with more information about this?
I'm sure Rolls Royce is more than capable of fixing this problem (they have to) ... personally I think IF it is a problem attributed to creep in the turbine blades (for example) then apart from being an event where Rolls will focus their attention towards rectification but also a good learning opportunity.
Something like this could probably point towards the validation (or invalidation) of their Uncontained Engine Rotor Failure Analysis (simply known as UERF) - specifically the trajectory of the debris and the possible Wingbox and Skins damage sites that may be produced in case this happened when the engine was installed.
I don't wish this to turn into a RR vs GE fest ... UERF is something that can happen to all engines !
747classic From Netherlands, joined Aug 2009, 2346 posts, RR: 15
Reply 6, posted (4 years 8 months 1 week 6 days 9 hours ago) and read 25695 times:
The source of the failure may have been corrected already, the fact remains that the engine failure was uncontained.
Does this mean that the surrounding engine core casing has to be strengthened ( addition of more weight) to prevent more uncontained engine failures, caused by a possible future (other) failure in the the single-stage intermediate pressure (IP) turbine.
Operating a twin over the ocean, you're always one engine failure from a total emergency.
SSPhoenix From United Kingdom, joined Aug 2010, 96 posts, RR: 0
Reply 7, posted (4 years 8 months 1 week 6 days 6 hours ago) and read 24916 times:
In UERF situation - there is a limit to which the surrounding casing can be reinforced - remember the turbines are one of the highest stressed components and once dislodged- the kinetic and intertial (rotation) energy of the debris is extremely high ...
the reinforcement for these components becomes unrealistically high if containment is to be 'enforced' - so I think they key here is to investigate (as Rolls has already done) the issue and focus towards making sure other components are not going to experience the same failure mode AND making sure that engine/wing strength requirements are maintained (not affected) for 'high' risk trajectories.
tdscanuck From Canada, joined Jan 2006, 12710 posts, RR: 80
Reply 10, posted (4 years 8 months 1 week 5 days 10 hours ago) and read 18408 times:
Quoting 747classic (Reply 6): The source of the failure may have been corrected already, the fact remains that the engine failure was uncontained.
You're allowed to have uncontained engine failures...it just depends on what the failure mode was.
Quoting 747classic (Reply 6): Does this mean that the surrounding engine core casing has to be strengthened ( addition of more weight) to prevent more uncontained engine failures, caused by a possible future (other) failure in the the single-stage intermediate pressure (IP) turbine.
If it was a rotor/disc failure, there's no requirement to strengthen the case because there's no requirement (or practical way) to contain such an event. The requirement is that you contain a single blade failure (plus whatever else the blade takes out when it fails). If a disc lets go, no practical containment in existence is going to stop it.
tepidhalibut From Iceland, joined Dec 2004, 211 posts, RR: 6
Reply 11, posted (4 years 8 months 1 week 5 days 8 hours ago) and read 18217 times:
Quoting tdscanuck (Reply 10): You're allowed to have uncontained engine failures...it just depends on what the failure mode was.
More importantly, the allowability depends upon the likelihood in service. It could be (speculation) that a bench test has discovered a very unusual mode of operation, or failure mode... if that combination of events will only be encountered every 1 x 10E-30 flights, then it may be acceptable. If it's encountered every 20 flights...probably not.
I'd be interested to see what the conclusion is, but I doubt I'll ever find out.
There was another thread out here (started by Keesje) which discussed that topic specifically. But for some reason I can not find that thread anymore, and is was there this afternoon. Which seems a bit strange to me. Because what you asked was quite heavily debated out here. .
keesje From , joined Dec 1969, posts, RR:
Reply 16, posted (4 years 8 months 5 days 15 hours ago) and read 16566 times:
Contrary to what some stated (in the thread that has been moved to tech-ops, for being to technical (?)) the engine in question would have been delivered to ANA.
The Trent 1000 engine involved in the failure was destined for an early All Nippon Airways Boeing 787. Rolls-Royce will initially deliver 'Package A' engines for the first ANA 787s before transitioning to the 'Package B' standard, which will bring specific fuel consumption within one percent of the original specification.
lightsaber From United States of America, joined Jan 2005, 13925 posts, RR: 100
Reply 23, posted (4 years 8 months 4 days 23 hours ago) and read 15530 times:
Quoting Baroque (Reply 22): They do imply it was not under normal conditions - whatever they might be of course!! But they would be well advised to explain what they were doing and what happened in more detail, you would think!
I 100% agree! But what if I'm being too optimistic? Aerospace engineering is 'trust but verify.' RR needs to allow the verify.