Rolls Royce knew about it. Somewhere, communications failed.

Originally posted by Vio1ion
Rolls Royce knew about it. Somewhere, communications failed.

How did you come to that conclusion?

Rolls Royce knew the issue happened - every one of their engines since the mid 1990s have had a real time data feed to their UK engineering center, but everything I have read has said that there was no cause for concern leading up to the failure.

The part that failed had no sensor monitoring, and the part where oil pooled had no sensor monitoring - both because they were not, at the time, a critical failure point. Rolls Royce knew the engine was leaking small quantities of oil, but all engines do especially when new (buy a new car, you get told the same thing - check the oil after 500 miles and top up, new engines can eat oil as they bed parts in).

Originally posted by RichardPrice

Originally posted by Vio1ion
Rolls Royce knew about it. Somewhere, communications failed.

How did you come to that conclusion?

The ABC report in the OP link suggests that too but I think it's muddled reporting. What it says is:

A Four Corners investigation into last year's mid-air explosion of a Qantas A380 jet engine raises serious concerns about quality controls at Rolls-Royce.

It reveals the engine-maker was aware of a faulty weld on an oil pipe in one its Trent 900 engines a year before the explosion happened.

Despite the initial warning, the company went on to manufacture another faulty pipe.

The other oil pipe they are talking about was an oil vent pipe, not an oil feed pipe, and it's not necessarily even the same failure mode nor the same cause of a misaligned counterbore. They apparently had made improvements to that part of the engine in revisions B and/or C and the rev A engine that failed didn't have those improvements yet, but everyone seems to be giving RR the benefit of the doubt that they didn't know the critical safety nature of the improvements. But of course only RR knows what they really knew about the safety nature of the B and C revisions.

If my take is correct, the story is they knew there was a potential for cracking on the A revision but they didn't know how fast the crack could propagate, based on all their previous experience. But I also wonder if they quantitatively established the vibrational stress levels of the full power takeoff from LA's short runway which may have been a contributing factor to the accelerated crack propagation.

I also have no idea if they had any knowledge of the manufacturing problem with the misaligned counterbore on this engine or any other Rev A engines beforehand, does anyone know about that? The preliminary ATSB report doesn't say, but maybe the final report will have more detail? I'm sure it will have more detail but I don't know to what extent they will have the RR manufacturing and quality control records available to them.

At least Qantas has been consistent.
Nearly every month they are guaranteed to scare the crap out of at least 300 paying customers.
It must be just like a big amusement park ride.

Apparently the engine debri came within cm's of the left wings flaps' hydraulic cables, so a very close call.

Also, could five Captains in the cockpit be a help or a hinderance? It appears that they did allow the main pilot to fly the plane without too much back seat driving.

Originally posted by lostinau
Also, could five Captains in the cockpit be a help or a hinderance?

I was wondering that too. I think in this case, he needed all the help he could get. It took forever just to get through the list of 60 or so faults, the pilot lost his voice reading all of them there were so many.

Having more captains independently run the landing scenario might have helped. That was so close, 4000' Runway, calculations showed they needed 3900' but they were able to stop in 3850' had they wanted. The fact that he got a stall warning, twice, while landing, was disconcerting to say the least. That's not a warning you want to hear. but he said he really couldn't speed up because had he been 3 knots faster he would have run out of runway. Zero margin for error, they did a good job.

That was a very close call.

Hello all,

This is a subject close to my heart as I work for the airline and work for the A-380 team as an engineer. As such I am privy to much which you dont hear about in the press, both the good and the bad. I have spoken here in another thread on this matter and can now reveal more. Now as for individual comments I will list the responses.

Richard Price,
Richard you are absolutely correct, RR did know in real time that the event had occurred but could not have reasonably expected it to happen. As you said there is no monitoring in that area so it's hard to predict, but more on that later.

Arbitrageur,
You have probably pointed out the most succinct points here and I will detail as follows,

"They apparently had made improvements to that part of the engine in revisions B and/or C and the rev A engine that failed didn't have those improvements yet"

Correct, the engine in question did NOT have the revisions done to it, it was a mod A engine.

"everyone seems to be giving RR the benefit of the doubt that they didn't know the critical safety nature of the improvements. But of course only RR knows what they really knew about the safety nature of the B and C revisions"

They did,... sort of. I had a conversation with a RR rep who inferred that they did in fact know of the misaligned counterboring on the IP/HP bearing stub pipe but did not realise the severity or danger that was posed. It was reasonably assumed that moding the engine would occur well before any issue would arise. On this general thesis I cannot blame them. As you yourself said,

"If my take is correct, the story is they knew there was a potential for cracking on the A revision but they didn't know how fast the crack could propagate, based on all their previous experience"

True, however as you also pointed out.

"But I also wonder if they quantitatively established the vibrational stress levels of the full power takeoff from LA's short runway which may have been a contributing factor to the accelerated crack propagation. "

And therein lies in my opinion their failure. They should have realised that Qantas were operating the highest thrust -972 variant and that LAX is well known for it's runway length. It's not like they didn't know. There have been repeated issues with fatigue cracking and vibration issues on the A-380 for Qantas (god knows how many cracks I have found!) and many of these surrounding the powerplant/pylon/strut area. What's more there have been for quite some time inspections called out for various components by RR that centre in that area, some of which are still continuing. For example there is an ongoing inspection of the IP/HP external oil supply tube "B" nut for signs of vibration induced backing off or pipe cracking leading to oil loss, and these inspections have led to a large number of rejected tubes and a consequential world wide shortage of these tubes. So in the end given all the evidence before hand they should have shown more prudence and told Qantas to limit takeoff weight out of LAX and therefore thrust setting with mod A engines. Not doing so in my opinion is where their negligence lies, not in producing an engine design with a fault, that can and will happen to anybody it is the nature of pushing the technology envelope.

As for the issue of too many cooks(captains) spoiling the broth? Well my opinion of the subject skipper is less than stellar despite the media propaganda machine. I have had dealings with him and frankly think the aircraft did far more that day than most uneducated people realise. It is fair enough to say that he was just the guy sitting in the left hand seat on the day(which he wasn't meant to be) and didn't ask for the notoriety. Let me just say that despite my own professional misgivings of this aircraft I believe that it's designers did far more that day to ensure the safety of the passengers, crew and aircraft than a cockpit full of captains (good or bad).

As for why the #:1 engine failed to shut down, the ATSB investigation was ongoing last I heard but is obviously connected with the numbers and amount of wiring looms severed or rendered useless in the incident. This is one of the aspects of this that I find most unnerving, that and the failure of so many hydraulic systems, it just should not have occurred according to the manual.

As a side note,
I was present when this documentary was shot as it was conducted in Sydney. In fact the few short scenes showing the flight crew operating through the windshield were down to the actions of yours truly! I was asked to drive in the nose docking to allow the ABC cameraman the access and was responsible for ensuring he was wearing a safety harness. The documentary was actually shot using two different aircraft, one in Hangar 96 and the other on the South run bay (OQG ?) in fact I have yet to check the footage but I think I may be a fuzzy red dot on a tug in the background of the run bay shots.

As a further side note, the repairs to OQA are due to start any day now with the aircraft scheduled to be redelivered sometime early next year with Airbus guaranteeing the repairs to not affect performance and with only around a 200 kg weight penalty.

LEE.

Originally posted by thebozeian
This is a subject close to my heart as I work for the airline and work for the A-380 team as an engineer. As such I am privy to much which you dont hear about in the press, both the good and the bad.

Thanks Lee, all I could do was speculate from what I've read and seen in the documentaries, but it's really great to get some information from a more reliable source like you, who may even be a fuzzy red dot in the documentary!

They should have realised that Qantas were operating the highest thrust -972 variant and that LAX is well known for it's runway length. It's not like they didn't know.

So they knew about the counterbore misalignment on Mod A! Thanks for answering that question. And they knew about the LA short takeoffs and high vibration.

But somehow they didn't put 2 and 2 together to figure out that the high vibration could accelerate a failure of the misaligned counterbore. Yeah I'd like to be a fly on the wall in the Rolls Royce conference rooms as they post mortem their failure to put those two things together to come up with a more realistic failure expectation. It just doesn't add up completely, does it?

Hopefully one of the things to come out of this will be more vibration stress testing by RR, it seems like they need it.

thebozeian, thanks for your excellent professional opinion on this subject. From what I understand the closest call was the fact that wing flap hydraulic lines may have been nearly cut by engine debri, making this an extremely close call.