Qantas latest engine out

[B190]

Whats the latest with the failure out of FAJS, it seems to have rattled the springboks.

[1a sound asleep]

"The aircraft has four engines and can safely fly on three engines," a Qantas spokesman said.

"There was no issue with safety and media reports that there was an explosion are incorrect."

The Springboks were meant to have landed in Sydney, aboard flight QF64, shortly after 2pm (AEST) today but they are now staying at a hotel in Johannesburg as Qantas decides whether to put them on a new aircraft

Read more: Qantas engine failure sends rugby's Springboks back home | News.com.au (http://www.news.com.au/breaking-news/qantas-engine-failure-sends-rugbys-springboks-back-home/story-e6frfku0-1226095726886#ixzz1SDZrcQAZ)

Got to ask how much these failures are costing with hotels, disruptions to scheduling.? Should sue somebody over this? Why have these RB211s become so nasty in the last few years? Lets blame Dixon and cronies

[ozbiggles]

I think its just a great ploy to help the Wallabies.
Now we just need to get the All Blacks on Jetstar....

[hotnhigh]

The $500 mill they are spending in singapore should fix the problems with qantas.
:yuk::ugh:

[ALAEA Fed Sec]

The formula here is simple guys.

Blades from the High Pressure Compressor stage 6 keep failing at the root. Once they let go, massive damage is caused as the part flies through the rest of the compressor and then the turbine hence all the sparks and heat. Qantas keep refering to this as an overheated engine that is shut down as a "precautionary measure". Of course they also say it is not a safety issue.

This aircraft, OJL had a similar failure on Eng 4 in BKK a month ago. The good news is that there is a known fix to this problem by way of modification. The bad news (for Qantas) is that they can't carry out the modification becasue they closed their Roller engine shop last year. The Asian shops they use now are all booked out so the mod is not being done until an engine comes off for routine service.

I'd be expecting a few more of these failures. I think this is about the 10th one.

[-438]

Well Qantas has to find the money for Jetstar's expansion from somewhere.
What could possibly go wrong?
Maybe Olivia can fix these engines.

[pa28capt]

This is a known issue with this engines as SP states.

Why are the media not onto the fact that the B747 is flying with engines not modified to a safe standard, apparently we are averaging an engine failure a week. Is this true?

This is disgraceful and management should be held accountable.

[Terrey]

Fed Sec,

I hope a Press Release is being sent out to all media outlets, stating the facts you mention above.

[DutchRoll]

Well don't expect certain aviation journos to be onto it any time soon.

Such a negative report on QF's management allowing systemic problems to affect the engine reliability of the RR 747-400 fleet might cost 3 business class tickets and 6 months' worth of nice lunches. :rolleyes:

[ALAEA Fed Sec]

I think I may just cut and paste my words directly onto the release. See you on the news tonight guys and gals.

[ALAEA Fed Sec]

Not 767 mate. The short 767 transits mean the compressor case doesn't cool down between flights. It is about the blade tip clearance.

[600ft-lb]

Maybe (just maybe) the reason why some real leadership all those years ago set up an engine overhaul shop was because when you're sending these machines to as far away as they can go in a single hop, you don't want to be stranded out there with one of your engines in bits. Having control over the process, not just accepting someone elses word for it.

But worlds best practice is to not have one of those so I suppose Qantas was doing it wrong for all those years until recently.:ugh:

[xer]

So a known safety problem with a known fix.

I cant believe this is not picked up the newpapers and the board are allowing it to slide.

So what happens when two engines let go on the same flight?

Will Olivia's reply be "it's a four engine plane and can fly on two engines"

So what happens when three engines let go on the same flight?

Will Olivia's reply be "it's a four engine plane and can... fly on one engine"

[ALAEA Fed Sec]

On 5 November 2010, a Boeing Company 747-438 aircraft, registered VH-OJD departed Changi Airport, Singapore on a scheduled flight to Sydney, New South Wales. When the aircraft was climbing through 2,000 ft, a loud bang was heard accompanied with aircraft yaw and vibration. The crew shut down the number one engine, declared a PAN and received approval from air traffic control for a return to Singapore. The crew then jettisoned fuel for about forty minutes. Emergency services were in attendance when the aircraft landed safely a short time later.

A subsequent examination confirmed that the engine had sustained serious damage as the result of a compressor blade release from the stage 1 high pressure compressor (HPC 1). The engine was replaced and the aircraft returned to service.

The aircraft operator is continuing to bring their RB211-524G engines to the latest modification status at engine shop visits. However, should the rate of engine failures increase significantly a review of current modification policy will be undertaken.

Investigation: AO-2010-090 - Total power loss - Boeing 747, VH-OJD, near Changi Airport, Singapore, 5 November 2010 (http://www.atsb.gov.au/publications/investigation_reports/2010/aair/ao-2010-090.aspx)

[buggerme]

Have we a spare engine to send over there ? The rate we are losing them it makes you wonder, we (the company) seem to be on a downward spiral going from one calamity to another, at least it wasn't a safety issue not like the left handed screwdrivers!

[Dak Man]

Bok plane's engine explodes: Sport: Rugby: Tri-Nations (http://www.sport24.co.za/Rugby/TriNations/Bok-planes-engine-explodes-20110715)

[stubby jumbo]

A mate of mine who is on the crew of this aircraft-sent me a text this morning saying that there are 2xPlatinum FF's who will NOT be getting back on board.

They handed in their card to the CSM -as they were getting off and said they were going home to Oz via SIN on SQ.

They were "lucky" enough to be on the QF32 Nancy ex SIN, then they were on the 744 with smoke detected on the flight deck (turn back) now this one ex JNB.

You know what they say about luck running in 3's:ooh:

Roll on redundancy... I'm counting down the days.
This outfit is becoming (oooppss HAS BECOME) the laughing stock of world aviation.

Virgin Australia........The (new) Spirit of Australia.

[bandit2]

A engine blowing up during flight isn`t a safety issue, but engineers working left handed is!!!! WTF?

[Angle of Attack]

Interesting article about this from Ben Sandilands, wonder if CASA is going to pounce again?

Should Qantas ground its Rolls-Royce engined 744s? | Plane Talking (http://blogs.crikey.com.au/planetalking/2011/07/16/should-qantas-ground-its-rolls-royce-engined-744s/)

Should Qantas ground its Rolls-Royce engined 744s?

Another Rolls-Royce RB211 engine has failed on a Qantas 747-400 putting the airline in a difficult position if it decides to continue operating those jets across long oceanic routes to South Africa and the US before they can be modified.

The latest incident involved last night’s Johannesburg-Sydney flight carrying the Springbok Rugby team to the Tri Nation series in which they will play Australia in the opening match in a week’s time.

After abnormal vibrations and temperatures became apparent in its number 3 engine the flight turned back to Johannesburg about an hour into its long journey across the southern Indian Ocean, and Qantas is making arrangements for a replacement flight.

The safety issue is that there is a known fault in this engine type’s high pressure compressor units in which turbine blades can break free and cause severe damage both inside and outside of the engine. In one of a recent series of at least nine such failures in the Rolls-Royce RB211 version used on Qantas Boeing 747-400s one of them ruptured the engine casing on a flight that had just left San Francisco for Sydney last year.

Another well publicised and destructive RB 211 engine failure occurred on a Qantas 747-400 on leaving Singapore last November carrying passengers stranded by the failure of a different Rolls-Royce engine type, a Trent 900, mounted on the wing of the airline’s first A380, when it had taken off as QF32 bound for Sydney.

That A380 is still on the ground at Changi Airport, undergoing extensive rebuilding, and the control crisis caused by the Trent 900′s disintegration was so severe that Qantas grounded its entire A380 fleet until the causes were understood and the remedies applied.

In the case of the much older RB211 design as used on 747s Rolls-Royce has devised a modification that prevents this type of turbine blade break away occurring. However the problem for Qantas is that its dedicated RB211 engine shop at Sydney was closed last year to save money, and its work outsourced to a Rolls-Royce facility in Hong Kong.

Other airlines using RB211s were much faster than Qantas to book their engines in for the modification work, meaning it has to stick to its original money saving strategy of not having the modifications made until each of these engine are due for a visit to the Hong Kong facility anyhow.

According to the Qantas engineers union, the ALAEA, whose members used to perform RB211 work in Sydney, this is the second failure of one of these engines on this same 747-400 in a month.

Although a Qantas spokesperson is alleged to have said that a 747 would fly safely on three engines and thus safety wasn’t an issue, that is a somewhat facile position to take in that once an engine fails on any type of jet the immediate concern of the pilots is to plan a response to a further engine failure, and the range, speed and altitude of the jet all diminish from that moment, and especially so for twin engined jets, but that is another story altogether.

In its report into the Singapore RB211 incident the ATSB says:

On 5 November 2010, a Boeing Company 747-438 aircraft, registered VH-OJD departed Changi Airport, Singapore on a scheduled flight to Sydney, New South Wales. When the aircraft was climbing through 2,000 ft, a loud bang was heard accompanied with aircraft yaw and vibration. The crew shut down the number one engine, declared a PAN and received approval from air traffic control for a return to Singapore. The crew then jettisoned fuel for about forty minutes. Emergency services were in attendance when the aircraft landed safely a short time later.

A subsequent examination confirmed that the engine had sustained serious damage as the result of a compressor blade release from the stage 1 high pressure compressor (HPC 1). The engine was replaced and the aircraft returned to service.

The aircraft operator is continuing to bring their RB211-524G engines to the latest modification status at engine shop visits. However, should the rate of engine failures increase significantly a review of current modification policy will be undertaken.

In the interests of plain english, that last paragraph means Qantas is prepared to take the risk of further failures in these engines rather than have them modified as quickly as possible.

It continues to fly them across two of the remotest oceanic routes in the world, between the US west coast and Australia, and between Australia and South Africa, as well as on some kangaroo route services to London via Singapore, Hong Kong and Bangkok.

Of course it may change its mind. Or CASA may change it for it. It seems odd that an airline that so commendably made safety its absolute priority in the case of the A380 incident, and the volcanic ash threat from Chile (yet not from the Indonesian volcanoes it regularly flies around) should have been so reluctant at least until today to speed up its RB211 modifications.

The decision to shut the RB211 engineering facility was wrong given that its stated intention is to keep some of the affected 747-400s flying until late this decade. It took out of the control of Qantas two of the critical comp0nents of its brand, namely safety and reliability. Whatever it might have saved has been lost. It is as big a disconnection from technical excellence as Jetstar deciding to make undocumented changes to its go around procedures for A320s, only to nearly lose one in a missed approach to Melbourne Airport in 2007, or the foolish decision to ban full reverse thrust landings in 747-400s to save pennies on fuel and brake maintenance, which preceded the crash landing of another 747 at Bangkok in 1999 in which the pilots made no attempt to engage reverse thrust before ploughing off the end of a runway into a golf course.

There is a need for Qantas to think about more than penny pinching and re-engage its management mind with safety first considerations. There is an urgent need for this to be done in relation to the RB211s, no matter how long or short they are going to remain in service after the August 24 restructuring is revealed.

CASA could not be contacted earlier today, and a message was left for Qantas hours ago.

[WanganuiLad]

Ozbiggles said. "I think its just a great ploy to help the Wallabies.
Now we just need to get the All Blacks on Jetstar...."

grasping at straws there Mate :D
..... they will be DC3ing under ash etc :)

http://www1.pictures.zimbio.com/gi/Crusaders+Fly+Wellington+DC3+zpObVoM0QIxl.jpg

Pete
How the heck does one do quotes in here, I scoured the FAQ

[teresa green]

Lets get it into perspective, over 16,000 hrs on jets, according to my log (and roughly worked out) about every 1700 hrs I had a turn back or some sort of engine failure, (big and small). This is on the DC9, B747, A300, 747/200/300. The only one that made it into the press was because Keating and a few other pollies were on board, out of CBR. Somehow I would think this would have still made it into press, even if the Boks were not on board. QF bashing is still alive and well. However if the Engineers can think of a way of helping the Wallabies, well I am all for it!:E:E

[Sonny Hammond]

It is pretty obvious that QF has a problem with the RB211's on the 400.
I flew them for several years with not so much as a mumur and now its full on failures on a regular basis.
Sandilands point is right, how can QF, without putting itself right in the breach, continue to operate certain remote routes with this knowledge?
To say that the 'rate of failure' is blah blah blah totally overlooks the issue at hand and is simply a management smokescreen.

If a 400 gets in serious problems as a result there will be feathers flying for years and years.
Mind you, in a month, they may not be flying anymore and this problem won't exist.

[600ft-lb]

Lets get it into perspective, over 16,000 hrs on jets, according to my log (and roughly worked out) about every 1700 hrs I had a turn back or some sort of engine failure, (big and small). This is on the DC9, B747, A300, 747/200/300. I know you have had quite a career Mr Green, but the original JT9's and JT8's were extremely unreliable engines compared to their modern counterparts.

The old jumbo engines used to flame out if you gassed it too quick and had a hole drilled in the throttle quadrant for a pin to be installed after engine start as a nasty work around to stop the engine being retarded back to full idle or it would flame out.

The RB211 in its first incarnation nearly sent Rolls Royce broke because it kept exploding.

Today jet engines are a mature technology, as can be demonstrated by some of the old RB211's on the wings of some Qantas aircraft, they went years beyond what was expected before they were due for overhaul.

It's the fact that as engines became more reliable that the idea of ETOPS became viable and killed off the 3 engined aircraft.

A mature, fully evolved engine such as the RB211 on the 744's shouldn't be exploding randomly like they are at the moment. Apparently its not a safety issue because there are 4 engines. The SFO failure included the turbin disk being ejected out the side, lucky it was away from the aircraft unlike QF32's.

Was QF32 with its 1 exploding engine 'not a safety issue' ?

[hewlett]

Due to the untenable situation with the reliability of the Rolls Royce powered 744 fleet and outrageously unsustainable cost of our international business, all Boeing 747 aircraft powered by Rolls Royce engines greater than 1 year old in the International fleet will be retired effective immediately, which unfortunately will lead to the closure of most key Qantas destinations and result in mass redundancies.
Fortunately, due to strategic decision making Jetstar has offered to fill the void and provide a fresh alternative for our valued customers. As a stopgap measure we will be relocating aircraft and crew from our subsiduary business units to minimise disruptions.
Sincerely
Al

[sani-com]

I wonder if any QF managers or members of the board are watching 7mate tonight?
The episode starts with "Modern airliners are among the most complex and reliable machines in common use. But occasionally, delays in fixing a known defect have lead to disaster." (regarding the 747 with the cargo door that opened in flight).

More likely they're watching Business Asia...

[Runaround Valve]

The original JT9D on the B747 had a bar installed aft of the thrust levers. Never used by ground engineers but was for flight crew only. It was known as the 'Bodie Bar' after a pilot in the USAF who did slam accelerations and deccelarations of engines. So I was told on an engine course. It was to prevent the engine going below a certain R P M possibly to avoid a slow spool up. Does anyone recall this ???.

[mustafagander]

Runaround Valve,

The thingo to which you refer was called a throttle bar or an idle bar. It's purpose in life was to prevent the retarding of the thrust levers too far when above FL290. It was engaged, slid into place actually, by the FE at FL290 on climb and stowed on descent below FL290.

The early JT9-3A engines operated very close to the surge line at higher altitudes and were very prone to surge without the higher idle rpm from the throttle bar. Idle acceleration was not much slower than current types. All B747s, AFAIK, shift to flight idle with approach flap selection and maintain this higher idle speed until 5 seconds, I think, after ground mode sensed. This is purely to satisfy GA engine acceleration requirements.

Does anyone else hear the fluttering of chickens coming home to roost????

[rogerk]

Johannesburg - The Springbok rugby team's flight to Australia was forced to return shortly after departing from Johannesburg on Friday night due to engine failure.

"The Qantas flight on which the team was travelling was forced to return to OR Tambo International Airport in Johannesburg less than two hours after take-off," the SA Rugby Union said in a statement.

Saru said the third engine on the Boeing 747 overheated, but it returned and landed safely in Johannesburg. The team would remain in Johannesburg overnight.

SARU says the plane returned safely to Johannesburg's OR Tambo International Airport, landing less than two hours after its departure.

"There was a loud bang and a bump and the captain told us we would be unable to continue our journey to Australia as engine No. 3 had failed," team spokesman Andy Colquhoun said. "So we dumped fuel and returned to Johannesburg.

[ARNSpoty]

well this means that the Ossis are under very tough luck when it comes to engines or just poor maintainces.

E

[Mstr Caution]

Qf stated the engine failure was not a safety issue.

In a later statement they also stated the aircraft returned to Jo'burg as a safety precaution.

So the engine failure was not a safety issue, but the diversion was? :ugh:

[blueloo]

QF shut down its world class engine maintenance plant. It now outsources and as a consequence gets a crap product. I believe they have now achieved their goal of worlds best practice (ie minimum maintenance required).


Why the previous and current CEO aren't held to account is amazing.

[Level100]

blueloo wrote

QF shut down its world class engine maintenance plant.


That is very interesting. Would you care and substantiate a little bit more this statement?
(i.e. when was the shutdown, who is the present subcontractor......)
Thanks.

[hoss]

and if it's not a safety issue then I guess the crew won't need to fill out any safety reports!

Well done to the crew, less writing more time for a beer.

[Angle of Attack]

Qantas PR fool quote

Shutting down one of the four engines on an aircraft is not a safety risk
to the passengers or crew. Qantas has never ‘cut costs’ on safety and never will Qantas invests more than $1 billion in maintenance each year

The likely cause of the incident, the failure of a single blade on a high
pressure compressor, is not an issue which is exclusive to Qantas. Other
airlines around the world have experienced this type of issue with RB211
engines.

This is not an issue which requires immediate action and the manufacturer has advised all airlines to undertake a modification at the next major engine overhaul.

Qantas has fast-tracked the program in recent months to bring the
modification forward on our aircraft, ahead of the manufacturer’s
recommended timeframe. Despite the union’s claims there is not a lack of capacity at engine overhaul facilities around the world.

The spokeperson craps on a lot more but my question can anyone compile the number of RB211 failures in recent times? maybe since the workshop closed in Sydney? Maybe Steve can shed some light on the failure rate since the RR shop shutdown vs before. Basically the hours flown by QF 744's has been pretty constant the last decade or so?

Just heard from a CASA source there may be an announcement too this week, they are getting a bit fidgety about it!

These QF spokespeople are about as effective as a wooden bbq at the bottom of the pacific ocean trench with a waterproof match...I'm sure Olivia can put spin about its a water proof match so it can still be lit underwater lol !

[SOPS]

Meanwhile...some small Middle East Airline called Emirates has just anounced a contract with GE and a spend of 120 million to build a complete engine care facility in Dubai. We had that in Australia once, didn't we?

[Sunfish]

It's not a safety issue until the second engine fails, then the entire cost savings of a generation of bean counters vanishes in hours.

[allthecoolnamesarego]

Steve,

I tried to cut and paste a comment, but the article has been modified before I could.
In the article (from the Age), it said the the last maintenance performed on that engine was done by QF engineers (according to Olivia).
Are you able to shed some light on this, so we can get some facts, and not spin?

Thanks Mate,

Cool names

[peuce]

I wouldn't have thought it mattered who had done the last maintenance. The fix to the known problem has to be done at a appropriately equipped and certified workshop ... of which QANTAS allegedly has none.

[27/09]

In the article (from the Age), it said the the last maintenance performed on that engine was done by QF engineers (according to Olivia).

And that maintenance was? Check the oil levels? Check the cowls were still locked closed? I bet it wasn't anything much more that that.

It's not what they tell the public it's what they don't say that matters.

[allthecoolnamesarego]

27/09

Exactly why I would like to know. I think QF might be a little 'fluid' with the truth....


typed with my left hand...

[27/09]

I think QF might be a little 'fluid' with the truth.... The common parlance over here is "being economical with the truth"

[ozbiggles]

When I was young and growing up in aviation there was two things that that said safety and reliability to me.
Qantas and Rolls Royce.
I guess as we grow older some things change.....not necessarily for the better.
If I hear one more quote from someone not aviation trained saying safety is our number one priority when in reality they are only worried about cutting costs I'm gonna.....It doesn't matter now, not even the public believe the spin anymore, they can see the evidence themselves.

[600ft-lb]

Sunfish
It's not a safety issue until the second engine fails, then the entire cost savings of a generation of bean counters vanishes in hours.

QF32 was in no danger from its single engine failure ?

[glekichi]

So why have modifications to fix this known problem of a safety critical nature not been mandated immediately by the regulator?

[LeadSled]

---- and Rolls Royce.

ozbiggles,

Never true of Rolls Royce.

Have a look at the Conway "reliability" ( some B707 and VC-10) versus the various P&W JT3D.

In the early days of RR on QF classics, at one stage the regulator threatened to ground the fleet, if there was one more double in flight failure.

At that stage, QF adopted the policy of running all brand new deliveries through the engine shop in Sydney, to turn out a sort of reliable engine.

The arguments between QF engineers and RR about how to balance an engine became the stuff of local legend ---- guess who was right.

Tootle pip!!

[Keg]

Once upon a time, an issue such as this would have been a very high priority to sort out for Qantas. Now it's happy to continue. Anyone else see shades of the Challenger and Columbia disasters in this? It's the same symptoms of group think.

Consider:
1. Cohesive group of management. They're all positive, there is pressure to maintain 'membership' and be seen to be 'on the team'. They have a high desire to 'achieve'. A feeling of 'us' against those horrible workers and engineers trying to stifle 'our' plans for a change to the airline.

2 They're insular without many 'nay sayers'.

3. They're under incredible stress from budgets, time frames, media setbacks and union unrest.

Overestimation of the quality of the group.

1. Illusion of invulnerability. We have this magnificent safety heritage. Safety is our biggest priority.

2. Inherent morality of group. 'We're doing the right thing'. We must continue on this track for the good of the shareholders. We wouldn't do anything stupid.

Close minded to adverse consequences

1. Rationalisation. Sure the engines keep failing but it's not a 'safety' issue and the pilots are handling it and the planes keep landing with no adverse impacts. The fact that these things have occurred since the closure of the EOC is coincidence. Our engineering is down at the same places as Lufthansa and Cathay , etc.

2. Stereotypes of outsiders. We see this in the Qantas response to the engineers. They're only doing this for pay claims. The engine was last maintained by Qantas engineers.

The bits that I can't see but would come out in any investation.

1. Self censorhip. Does someone within the group know information but doesn't want to share it because it will disrupt 'everything'- the budget, the closure of EOC, the 'company line' that safety is most important, the IR agenda.

2. Direct Pressure. Is someone having the blow torch applied to their belly not to disrupt what is going on. Have the warnings been overt or even implied?

3. Illusion of unanimity. If the above two are happening then the ultimate decision makers would believe- and will be astonished when that belief is shown to be misplaced- that they are all unanimous in the course of action being under taken.

These were all things that came out of the first Shuttle prang and were sadly confirmed again in the second shuttle prang. It's all too obvious that it's going on at Qantas as well. I hope and pray that the crews left to deal with these failures are left with a situation that is able to be managed rather than face a situation like that the shuttle crews faced who though they fought bravely, did not yet realise they were already doomed.

[ozbiggles]

Keg, what a good post. True of many company mindsets I guess and it always takes an almighty bang to sort it out. The cold hard facts hit hard when you read the official report on what those aboard Challenger went through after the initial explosion. It probably won't be to different from those on the Air France jet. Again a known issue that it was thought safe to fix when time and not the safety case permitted.
Lead sled. Knowing now what I do I agree with you. Its amazing as you grow up how you begin to see though the PR and ask questions and seek proof. Its not always a pretty thing.

[teresa green]

600ft, if my memory serves me correctly the JT9 in QF was phased out around 1982 and RB211's installed. My point is we had problems then, and you have problems now, there is no such thing as a perfect aircraft or a perfect donk, as the A380 proved not so long ago. All the bells and whistles in your 'advanced technology" are not going to provide you with a guaranteed trouble free ride, it never will, not with so many moving components. I would even suggest that is was probably easier in my time, because you relied more on your experience, what a instrument was telling you, and your own intuition, rather than having to cope with mixed messages from a computer as well.(Which is what the A380 Skipper was getting) you might see our flying as antiquated, we see yours as boring, not pilots, but systems managers. Its called progress. :(

[Going Boeing]

Posted by LeadSled
In the early days of RR on QF classics, at one stage the regulator threatened to ground the fleet, if there was one more double in flight failure.

I'm not aware of any double engine failures on QF RR classics - can you give us some details. Legend says that there was a double failure on a P&W JT9D powered B747-200 off Rwy16 in Sydney & they only just cleared Kernel - but that was before my time.

The arguments between QF engineers and RR about how to balance an engine became the stuff of local legend ---- guess who was right.

LAME's that I met in the EOC confirmed that. A lot of mods that RR brought out were as a result of investigation by QF engineers - including recommending the fix.

[Metro man]

Any accident is going to be a lawyers picnic.

The phrases:

"Knowingly continued to operate with a serious defect."

"Reckless disregard for safety."

"Placed profits ahead of lives."

"Should have grounded the fleet until the problem was sorted out."

"Subjected passengers to an unacceptable level of risk."

Are sure to come up in the resulting court cases.

[600ft-lb]

Just to counter any spin about these engines when they go pop. A few reminders;
http://img804.imageshack.us/img804/2628/sfo.jpg (http://imageshack.us/photo/my-images/804/sfo.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
http://img807.imageshack.us/img807/9799/oqac.jpg (http://imageshack.us/photo/my-images/807/oqac.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
http://img832.imageshack.us/img832/7707/aa2jm.jpg (http://imageshack.us/photo/my-images/832/aa2jm.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
http://imageshack.us/photo/my-images/804/sfo.jpg
http://imageshack.us/photo/my-images/807/oqac.jpg
http://imageshack.us/photo/my-images/832/aa2jm.jpg

3 Different engines, RB211, Trent 900, CF6. All completely uncontained. 2 of those pics are unlucky enough to be Qantas aircraft.

Its a game of russian roulette when engines explode, a big heavy chunk of metal traveling near supersonic and a pressurized vessel with 40 to 60 thou thick of aluminium right next to it.

For them to say it's not a safety issue is easy, after the fact when there's been no damage to the fuselage/wing structure or loss of life.

As a reminder, the Trent 900 caused, as per the ATSB report;
The flight crew recalled the following systems warnings on the ECAM after the failure of the No 2 engine
engines No 1 and 4 operating in a degraded mode
GREEN hydraulic system – low system pressure and low fluid level
YELLOW hydraulic system – engine No 4 pump errors
failure of the alternating current (AC) electrical No 1 and 2 bus systems8
flight controls operating in alternate law
wing slats inoperative
flight controls – ailerons partial control only
flight controls – reduced spoiler control
landing gear control and indicator warnings
multiple brake system messages
engine anti-ice and air data sensor messages
multiple fuel system messages, including a fuel jettison fault
centre of gravity messages
autothrust and autoland inoperative
No 1 engine generator drive disconnected
left wing pneumatic bleed leaks
avionics system overheat.

[ALAEA Fed Sec]

Sorry been out today, just to answer a few questions.

Qantas are very misleading when they talk about an aircraft or engine's "last maintenance". If it suits they refer to the heavy maintenance or if that doesn't work for them they will use the last servicing check "oils and walk around inspection".

I hear today that the spokesmodel said the last check was done in Australia. So what, the problem here is not about the last check, it is about the mod that they know the donk needs but they can't do becasue they closed their workshop.

The last check was actually done in J'burg becasue that's where she flew out of. The last overhaul may have been in Sydney but the mod that is required was not requested. A few dollars saved, millions now lost.

This aircraft has had both engines 3 and 4 go within a couple of months. Talk about single engine failures or losing two together is fine but I think all would understand that a dropped engine increases the load on the remaining ones. If one is on the verge of popping, it is more likely to let go when it is subject to an increased load. I wouldn't want to do a go-around when two of them are gone.

Steve P

[ozbiggles]

Or as QF 32 proved, lose 1 and it can damage/take out the one next to it, let alone other systems.

[Sunfish]

Metro Man:

Any accident is going to be a lawyers picnic.

The phrases:

"Knowingly continued to operate with a serious defect."

"Reckless disregard for safety."

"Placed profits ahead of lives."

"Should have grounded the fleet until the problem was sorted out."

"Subjected passengers to an unacceptable level of risk."

Are sure to come up in the resulting court cases.

No! No! No! Metro man! You just don't get it do you?

When a Qantas 747 is finally lost with all on board, as is bound to happen shortly; this is what Wirthless and the Qantas loving media will spout:

"Pilot error".

"Cabin Crew mistakes and errors".

"Manufacturers defect".

"Maintenance Contractor error".

"Isolated incident".

"Complied with all regulations".

"Followed manufacturers advice".

"Followed expert advice".

"Complied with industry practice".

"Natural justice" for Qantas.

"Procedural fairness" for Qantas.

"Innocent until proven guilty".

"Acceptable level of risk".

"Appropriate compensation".

Don't listen to me, just look up James Hardie and Asbestos for an inexhaustible supply of weasel words.

[27/09]

Sunfish

When a Qantas 747 is finally lost with all on board, as is bound to happen shortly;

I really hope you're wrong

[Sunfish]

27/09:

I really hope you're wrong

Balance of probabilities mate. I know nothing specific, I'm merely applying Richard Feynmans dictum on the Challenger disaster, reproduced in full below:

Introduction:
It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management. What are the causes and consequences of this lack of agreement? Since 1 part in 100,000 would imply that one could put a Shuttle up each day for 300 years expecting to lose only one, we could properly ask "What is the cause of management's fantastic faith in the machinery?"

We have also found that certification criteria used in Flight Readiness Reviews often develop a gradually decreasing strictness. The argument that the same risk was flown before without failure is often accepted as an argument for the safety of accepting it again. Because of this, obvious weaknesses are accepted again and again, sometimes without a sufficiently serious attempt to remedy them, or to delay a flight because of their continued presence.

There are several sources of information. There are published criteria for certification, including a history of modifications in the form of waivers and deviations. In addition, the records of the Flight Readiness Reviews for each flight document the arguments used to accept the risks of the flight. Information was obtained from the direct testimony and the reports of the range safety officer, Louis J. Ullian, with respect to the history of success of solid fuel rockets. There was a further study by him (as chairman of the launch abort safety panel (LASP)) in an attempt to determine the risks involved in possible accidents leading to radioactive contamination from attempting to fly a plutonium power supply (RTG) for future planetary missions. The NASA study of the same question is also available. For the History of the Space Shuttle Main Engines, interviews with management and engineers at Marshall, and informal interviews with engineers at Rocketdyne, were made. An independent (Cal Tech) mechanical engineer who consulted for NASA about engines was also interviewed informally. A visit to Johnson was made to gather information on the reliability of the avionics (computers, sensors, and effectors). Finally there is a report "A Review of Certification Practices, Potentially Applicable to Man-rated Reusable Rocket Engines," prepared at the Jet Propulsion Laboratory by N. Moore, et al., in February, 1986, for NASA Headquarters, Office of Space Flight. It deals with the methods used by the FAA and the military to certify their gas turbine and rocket engines. These authors were also interviewed informally.

Solid Rockets (SRB)
An estimate of the reliability of solid rockets was made by the range safety officer, by studying the experience of all previous rocket flights. Out of a total of nearly 2,900 flights, 121 failed (1 in 25). This includes, however, what may be called, early errors, rockets flown for the first few times in which design errors are discovered and fixed. A more reasonable figure for the mature rockets might be 1 in 50. With special care in the selection of parts and in inspection, a figure of below 1 in 100 might be achieved but 1 in 1,000 is probably not attainable with today's technology. (Since there are two rockets on the Shuttle, these rocket failure rates must be doubled to get Shuttle failure rates from Solid Rocket Booster failure.)

NASA officials argue that the figure is much lower. They point out that these figures are for unmanned rockets but since the Shuttle is a manned vehicle "the probability of mission success is necessarily very close to 1.0." It is not very clear what this phrase means. Does it mean it is close to 1 or that it ought to be close to 1? They go on to explain "Historically this extremely high degree of mission success has given rise to a difference in philosophy between manned space flight programs and unmanned programs; i.e., numerical probability usage versus engineering judgment." (These quotations are from "Space Shuttle Data for Planetary Mission RTG Safety Analysis," Pages 3-1, 3-1, February 15, 1985, NASA, JSC.) It is true that if the probability of failure was as low as 1 in 100,000 it would take an inordinate number of tests to determine it ( you would get nothing but a string of perfect flights from which no precise figure, other than that the probability is likely less than the number of such flights in the string so far). But, if the real probability is not so small, flights would show troubles, near failures, and possible actual failures with a reasonable number of trials. and standard statistical methods could give a reasonable estimate. In fact, previous NASA experience had shown, on occasion, just such difficulties, near accidents, and accidents, all giving warning that the probability of flight failure was not so very small. The inconsistency of the argument not to determine reliability through historical experience, as the range safety officer did, is that NASA also appeals to history, beginning "Historically this high degree of mission success..."

Finally, if we are to replace standard numerical probability usage with engineering judgment, why do we find such an enormous disparity between the management estimate and the judgment of the engineers? It would appear that, for whatever purpose, be it for internal or external consumption, the management of NASA exaggerates the reliability of its product, to the point of fantasy.

The history of the certification and Flight Readiness Reviews will not be repeated here. (See other part of Commission reports.) The phenomenon of accepting for flight, seals that had shown erosion and blow-by in previous flights, is very clear. The Challenger flight is an excellent example. There are several references to flights that had gone before. The acceptance and success of these flights is taken as evidence of safety. But erosion and blow-by are not what the design expected. They are warnings that something is wrong. The equipment is not operating as expected, and therefore there is a danger that it can operate with even wider deviations in this unexpected and not thoroughly understood way. The fact that this danger did not lead to a catastrophe before is no guarantee that it will not the next time, unless it is completely understood. When playing Russian roulette the fact that the first shot got off safely is little comfort for the next. The origin and consequences of the erosion and blow-by were not understood. They did not occur equally on all flights and all joints; sometimes more, and sometimes less. Why not sometime, when whatever conditions determined it were right, still more leading to catastrophe?

In spite of these variations from case to case, officials behaved as if they understood it, giving apparently logical arguments to each other often depending on the "success" of previous flights. For example. in determining if flight 51-L was safe to fly in the face of ring erosion in flight 51-C, it was noted that the erosion depth was only one-third of the radius. It had been noted in an experiment cutting the ring that cutting it as deep as one radius was necessary before the ring failed. Instead of being very concerned that variations of poorly understood conditions might reasonably create a deeper erosion this time, it was asserted, there was "a safety factor of three." This is a strange use of the engineer's term ,"safety factor." If a bridge is built to withstand a certain load without the beams permanently deforming, cracking, or breaking, it may be designed for the materials used to actually stand up under three times the load. This "safety factor" is to allow for uncertain excesses of load, or unknown extra loads, or weaknesses in the material that might have unexpected flaws, etc. If now the expected load comes on to the new bridge and a crack appears in a beam, this is a failure of the design. There was no safety factor at all; even though the bridge did not actually collapse because the crack went only one-third of the way through the beam. The O-rings of the Solid Rocket Boosters were not designed to erode. Erosion was a clue that something was wrong. Erosion was not something from which safety can be inferred.

There was no way, without full understanding, that one could have confidence that conditions the next time might not produce erosion three times more severe than the time before. Nevertheless, officials fooled themselves into thinking they had such understanding and confidence, in spite of the peculiar variations from case to case. A mathematical model was made to calculate erosion. This was a model based not on physical understanding but on empirical curve fitting. To be more detailed, it was supposed a stream of hot gas impinged on the O-ring material, and the heat was determined at the point of stagnation (so far, with reasonable physical, thermodynamic laws). But to determine how much rubber eroded it was assumed this depended only on this heat by a formula suggested by data on a similar material. A logarithmic plot suggested a straight line, so it was supposed that the erosion varied as the .58 power of the heat, the .58 being determined by a nearest fit. At any rate, adjusting some other numbers, it was determined that the model agreed with the erosion (to depth of one-third the radius of the ring). There is nothing much so wrong with this as believing the answer! Uncertainties appear everywhere. How strong the gas stream might be was unpredictable, it depended on holes formed in the putty. Blow-by showed that the ring might fail even though not, or only partially eroded through. The empirical formula was known to be uncertain, for it did not go directly through the very data points by which it was determined. There were a cloud of points some twice above, and some twice below the fitted curve, so erosions twice predicted were reasonable from that cause alone. Similar uncertainties surrounded the other constants in the formula, etc., etc. When using a mathematical model careful attention must be given to uncertainties in the model.

Liquid Fuel Engine (SSME)
During the flight of 51-L the three Space Shuttle Main Engines all worked perfectly, even, at the last moment, beginning to shut down the engines as the fuel supply began to fail. The question arises, however, as to whether, had it failed, and we were to investigate it in as much detail as we did the Solid Rocket Booster, we would find a similar lack of attention to faults and a deteriorating reliability. In other words, were the organization weaknesses that contributed to the accident confined to the Solid Rocket Booster sector or were they a more general characteristic of NASA? To that end the Space Shuttle Main Engines and the avionics were both investigated. No similar study of the Orbiter, or the External Tank were made.

The engine is a much more complicated structure than the Solid Rocket Booster, and a great deal more detailed engineering goes into it. Generally, the engineering seems to be of high quality and apparently considerable attention is paid to deficiencies and faults found in operation.

The usual way that such engines are designed (for military or civilian aircraft) may be called the component system, or bottom-up design. First it is necessary to thoroughly understand the properties and limitations of the materials to be used (for turbine blades, for example), and tests are begun in experimental rigs to determine those. With this knowledge larger component parts (such as bearings) are designed and tested individually. As deficiencies and design errors are noted they are corrected and verified with further testing. Since one tests only parts at a time these tests and modifications are not overly expensive. Finally one works up to the final design of the entire engine, to the necessary specifications. There is a good chance, by this time that the engine will generally succeed, or that any failures are easily isolated and analyzed because the failure modes, limitations of materials, etc., are so well understood. There is a very good chance that the modifications to the engine to get around the final difficulties are not very hard to make, for most of the serious problems have already been discovered and dealt with in the earlier, less expensive, stages of the process.

The Space Shuttle Main Engine was handled in a different manner, top down, we might say. The engine was designed and put together all at once with relatively little detailed preliminary study of the material and components. Then when troubles are found in the bearings, turbine blades, coolant pipes, etc., it is more expensive and difficult to discover the causes and make changes. For example, cracks have been found in the turbine blades of the high pressure oxygen turbopump. Are they caused by flaws in the material, the effect of the oxygen atmosphere on the properties of the material, the thermal stresses of startup or shutdown, the vibration and stresses of steady running, or mainly at some resonance at certain speeds, etc.? How long can we run from crack initiation to crack failure, and how does this depend on power level? Using the completed engine as a test bed to resolve such questions is extremely expensive. One does not wish to lose an entire engine in order to find out where and how failure occurs. Yet, an accurate knowledge of this information is essential to acquire a confidence in the engine reliability in use. Without detailed understanding, confidence can not be attained.

A further disadvantage of the top-down method is that, if an understanding of a fault is obtained, a simple fix, such as a new shape for the turbine housing, may be impossible to implement without a redesign of the entire engine.

The Space Shuttle Main Engine is a very remarkable machine. It has a greater ratio of thrust to weight than any previous engine. It is built at the edge of, or outside of, previous engineering experience. Therefore, as expected, many different kinds of flaws and difficulties have turned up. Because, unfortunately, it was built in the top-down manner, they are difficult to find and fix. The design aim of a lifetime of 55 missions equivalent firings (27,000 seconds of operation, either in a mission of 500 seconds, or on a test stand) has not been obtained. The engine now requires very frequent maintenance and replacement of important parts, such as turbopumps, bearings, sheet metal housings, etc. The high-pressure fuel turbopump had to be replaced every three or four mission equivalents (although that may have been fixed, now) and the high pressure oxygen turbopump every five or six. This is at most ten percent of the original specification. But our main concern here is the determination of reliability.

In a total of about 250,000 seconds of operation, the engines have failed seriously perhaps 16 times. Engineering pays close attention to these failings and tries to remedy them as quickly as possible. This it does by test studies on special rigs experimentally designed for the flaws in question, by careful inspection of the engine for suggestive clues (like cracks), and by considerable study and analysis. In this way, in spite of the difficulties of top-down design, through hard work, many of the problems have apparently been solved.

A list of some of the problems follows. Those followed by an asterisk (*) are probably solved:

Turbine blade cracks in high pressure fuel turbopumps (HPFTP). (May have been solved.)
Turbine blade cracks in high pressure oxygen turbopumps (HPOTP).
Augmented Spark Igniter (ASI) line rupture.*
Purge check valve failure.*
ASI chamber erosion.*
HPFTP turbine sheet metal cracking.
HPFTP coolant liner failure.*
Main combustion chamber outlet elbow failure.*
Main combustion chamber inlet elbow weld offset.*
HPOTP subsynchronous whirl.*
Flight acceleration safety cutoff system (partial failure in a redundant system).*
Bearing spalling (partially solved).
A vibration at 4,000 Hertz making some engines inoperable, etc.

Many of these solved problems are the early difficulties of a new design, for 13 of them occurred in the first 125,000 seconds and only three in the second 125,000 seconds. Naturally, one can never be sure that all the bugs are out, and, for some, the fix may not have addressed the true cause. Thus, it is not unreasonable to guess there may be at least one surprise in the next 250,000 seconds, a probability of 1/500 per engine per mission. On a mission there are three engines, but some accidents would possibly be contained, and only affect one engine. The system can abort with only two engines. Therefore let us say that the unknown suprises do not, even of themselves, permit us to guess that the probability of mission failure do to the Space Shuttle Main Engine is less than 1/500. To this we must add the chance of failure from known, but as yet unsolved, problems (those without the asterisk in the list above). These we discuss below. (Engineers at Rocketdyne, the manufacturer, estimate the total probability as 1/10,000. Engineers at marshal estimate it as 1/300, while NASA management, to whom these engineers report, claims it is 1/100,000. An independent engineer consulting for NASA thought 1 or 2 per 100 a reasonable estimate.)

The history of the certification principles for these engines is confusing and difficult to explain. Initially the rule seems to have been that two sample engines must each have had twice the time operating without failure as the operating time of the engine to be certified (rule of 2x). At least that is the FAA practice, and NASA seems to have adopted it, originally expecting the certified time to be 10 missions (hence 20 missions for each sample). Obviously the best engines to use for comparison would be those of greatest total (flight plus test) operating time -- the so-called "fleet leaders." But what if a third sample and several others fail in a short time? Surely we will not be safe because two were unusual in lasting longer. The short time might be more representative of the real possibilities, and in the spirit of the safety factor of 2, we should only operate at half the time of the short-lived samples.

The slow shift toward decreasing safety factor can be seen in many examples. We take that of the HPFTP turbine blades. First of all the idea of testing an entire engine was abandoned. Each engine number has had many important parts (like the turbopumps themselves) replaced at frequent intervals, so that the rule must be shifted from engines to components. We accept an HPFTP for a certification time if two samples have each run successfully for twice that time (and of course, as a practical matter, no longer insisting that this time be as large as 10 missions). But what is "successfully?" The FAA calls a turbine blade crack a failure, in order, in practice, to really provide a safety factor greater than 2. There is some time that an engine can run between the time a crack originally starts until the time it has grown large enough to fracture. (The FAA is contemplating new rules that take this extra safety time into account, but only if it is very carefully analyzed through known models within a known range of experience and with materials thoroughly tested. None of these conditions apply to the Space Shuttle Main Engine.

Cracks were found in many second stage HPFTP turbine blades. In one case three were found after 1,900 seconds, while in another they were not found after 4,200 seconds, although usually these longer runs showed cracks. To follow this story further we shall have to realize that the stress depends a great deal on the power level. The Challenger flight was to be at, and previous flights had been at, a power level called 104% of rated power level during most of the time the engines were operating. Judging from some material data it is supposed that at the level 104% of rated power level, the time to crack is about twice that at 109% or full power level (FPL). Future flights were to be at this level because of heavier payloads, and many tests were made at this level. Therefore dividing time at 104% by 2, we obtain units called equivalent full power level (EFPL). (Obviously, some uncertainty is introduced by that, but it has not been studied.) The earliest cracks mentioned above occurred at 1,375 EFPL.

Now the certification rule becomes "limit all second stage blades to a maximum of 1,375 seconds EFPL." If one objects that the safety factor of 2 is lost it is pointed out that the one turbine ran for 3,800 seconds EFPL without cracks, and half of this is 1,900 so we are being more conservative. We have fooled ourselves in three ways. First we have only one sample, and it is not the fleet leader, for the other two samples of 3,800 or more seconds had 17 cracked blades between them. (There are 59 blades in the engine.) Next we have abandoned the 2x rule and substituted equal time. And finally, 1,375 is where we did see a crack. We can say that no crack had been found below 1,375, but the last time we looked and saw no cracks was 1,100 seconds EFPL. We do not know when the crack formed between these times, for example cracks may have formed at 1,150 seconds EFPL. (Approximately 2/3 of the blade sets tested in excess of 1,375 seconds EFPL had cracks. Some recent experiments have, indeed, shown cracks as early as 1,150 seconds.) It was important to keep the number high, for the Challenger was to fly an engine very close to the limit by the time the flight was over.

Finally it is claimed that the criteria are not abandoned, and the system is safe, by giving up the FAA convention that there should be no cracks, and considering only a completely fractured blade a failure. With this definition no engine has yet failed. The idea is that since there is sufficient time for a crack to grow to a fracture we can insure that all is safe by inspecting all blades for cracks. If they are found, replace them, and if none are found we have enough time for a safe mission. This makes the crack problem not a flight safety problem, but merely a maintenance problem.

This may in fact be true. But how well do we know that cracks always grow slowly enough that no fracture can occur in a mission? Three engines have run for long times with a few cracked blades (about 3,000 seconds EFPL) with no blades broken off.

But a fix for this cracking may have been found. By changing the blade shape, shot-peening the surface, and covering with insulation to exclude thermal shock, the blades have not cracked so far.

A very similar story appears in the history of certification of the HPOTP, but we shall not give the details here.

It is evident, in summary, that the Flight Readiness Reviews and certification rules show a deterioration for some of the problems of the Space Shuttle Main Engine that is closely analogous to the deterioration seen in the rules for the Solid Rocket Booster.
Avionics
By "avionics" is meant the computer system on the Orbiter as well as its input sensors and output actuators. At first we will restrict ourselves to the computers proper and not be concerned with the reliability of the input information from the sensors of temperature, pressure, etc., nor with whether the computer output is faithfully followed by the actuators of rocket firings, mechanical controls, displays to astronauts, etc.

The computer system is very elaborate, having over 250,000 lines of code. It is responsible, among many other things, for the automatic control of the entire ascent to orbit, and for the descent until well into the atmosphere (below Mach 1) once one button is pushed deciding the landing site desired. It would be possible to make the entire landing automatically (except that the landing gear lowering signal is expressly left out of computer control, and must be provided by the pilot, ostensibly for safety reasons) but such an entirely automatic landing is probably not as safe as a pilot controlled landing. During orbital flight it is used in the control of payloads, in displaying information to the astronauts, and the exchange of information to the ground. It is evident that the safety of flight requires guaranteed accuracy of this elaborate system of computer hardware and software.

In brief, the hardware reliability is ensured by having four essentially independent identical computer systems. Where possible each sensor also has multiple copies, usually four, and each copy feeds all four of the computer lines. If the inputs from the sensors disagree, depending on circumstances, certain averages, or a majority selection is used as the effective input. The algorithm used by each of the four computers is exactly the same, so their inputs (since each sees all copies of the sensors) are the same. Therefore at each step the results in each computer should be identical. From time to time they are compared, but because they might operate at slightly different speeds a system of stopping and waiting at specific times is instituted before each comparison is made. If one of the computers disagrees, or is too late in having its answer ready, the three which do agree are assumed to be correct and the errant computer is taken completely out of the system. If, now, another computer fails, as judged by the agreement of the other two, it is taken out of the system, and the rest of the flight canceled, and descent to the landing site is instituted, controlled by the two remaining computers. It is seen that this is a redundant system since the failure of only one computer does not affect the mission. Finally, as an extra feature of safety, there is a fifth independent computer, whose memory is loaded with only the programs of ascent and descent, and which is capable of controlling the descent if there is a failure of more than two of the computers of the main line four.

There is not enough room in the memory of the main line computers for all the programs of ascent, descent, and payload programs in flight, so the memory is loaded about four time from tapes, by the astronauts.

Because of the enormous effort required to replace the software for such an elaborate system, and for checking a new system out, no change has been made to the hardware since the system began about fifteen years ago. The actual hardware is obsolete; for example, the memories are of the old ferrite core type. It is becoming more difficult to find manufacturers to supply such old-fashioned computers reliably and of high quality. Modern computers are very much more reliable, can run much faster, simplifying circuits, and allowing more to be done, and would not require so much loading of memory, for the memories are much larger.

The software is checked very carefully in a bottom-up fashion. First, each new line of code is checked, then sections of code or modules with special functions are verified. The scope is increased step by step until the new changes are incorporated into a complete system and checked. This complete output is considered the final product, newly released. But completely independently there is an independent verification group, that takes an adversary attitude to the software development group, and tests and verifies the software as if it were a customer of the delivered product. There is additional verification in using the new programs in simulators, etc. A discovery of an error during verification testing is considered very serious, and its origin studied very carefully to avoid such mistakes in the future. Such unexpected errors have been found only about six times in all the programming and program changing (for new or altered payloads) that has been done. The principle that is followed is that all the verification is not an aspect of program safety, it is merely a test of that safety, in a non-catastrophic verification. Flight safety is to be judged solely on how well the programs do in the verification tests. A failure here generates considerable concern.

To summarize then, the computer software checking system and attitude is of the highest quality. There appears to be no process of gradually fooling oneself while degrading standards so characteristic of the Solid Rocket Booster or Space Shuttle Main Engine safety systems. To be sure, there have been recent suggestions by management to curtail such elaborate and expensive tests as being unnecessary at this late date in Shuttle history. This must be resisted for it does not appreciate the mutual subtle influences, and sources of error generated by even small changes of one part of a program on another. There are perpetual requests for changes as new payloads and new demands and modifications are suggested by the users. Changes are expensive because they require extensive testing. The proper way to save money is to curtail the number of requested changes, not the quality of testing for each.

One might add that the elaborate system could be very much improved by more modern hardware and programming techniques. Any outside competition would have all the advantages of starting over, and whether that is a good idea for NASA now should be carefully considered.





Feynman's Personal Observations On The Reliability Of The Space Shuttle (http://www.fotuva.org/feynman/challenger-appendix.html)

[Sunfish]

Here is the rest of it. If anyone cannot read and understand this, or finds it too long, then you have no business commenting on safety sensitive activities including aviation.

Finally, returning to the sensors and actuators of the avionics system, we find that the attitude to system failure and reliability is not nearly as good as for the computer system. For example, a difficulty was found with certain temperature sensors sometimes failing. Yet 18 months later the same sensors were still being used, still sometimes failing, until a launch had to be scrubbed because two of them failed at the same time. Even on a succeeding flight this unreliable sensor was used again. Again reaction control systems, the rocket jets used for reorienting and control in flight still are somewhat unreliable. There is considerable redundancy, but a long history of failures, none of which has yet been extensive enough to seriously affect flight. The action of the jets is checked by sensors, and, if they fail to fire the computers choose another jet to fire. But they are not designed to fail, and the problem should be solved.

Conclusions
If a reasonable launch schedule is to be maintained, engineering often cannot be done fast enough to keep up with the expectations of originally conservative certification criteria designed to guarantee a very safe vehicle. In these situations, subtly, and often with apparently logical arguments, the criteria are altered so that flights may still be certified in time. They therefore fly in a relatively unsafe condition, with a chance of failure of the order of a percent (it is difficult to be more accurate).

Official management, on the other hand, claims to believe the probability of failure is a thousand times less. One reason for this may be an attempt to assure the government of NASA perfection and success in order to ensure the supply of funds. The other may be that they sincerely believed it to be true, demonstrating an almost incredible lack of communication between themselves and their working engineers.

In any event this has had very unfortunate consequences, the most serious of which is to encourage ordinary citizens to fly in such a dangerous machine, as if it had attained the safety of an ordinary airliner. The astronauts, like test pilots, should know their risks, and we honor them for their courage. Who can doubt that McAuliffe was equally a person of great courage, who was closer to an awareness of the true risk than NASA management would have us believe?

Let us make recommendations to ensure that NASA officials deal in a world of reality in understanding technological weaknesses and imperfections well enough to be actively trying to eliminate them. They must live in reality in comparing the costs and utility of the Shuttle to other methods of entering space. And they must be realistic in making contracts, in estimating costs, and the difficulty of the projects. Only realistic flight schedules should be proposed, schedules that have a reasonable chance of being met. If in this way the government would not support them, then so be it. NASA owes it to the citizens from whom it asks support to be frank, honest, and informative, so that these citizens can make the wisest decisions for the use of their limited resources.

For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.

[27/09]

Sunfish,

An interesting read, like most of the stuff you post.

It seems so often lessons are not learned from these disasters.

[Sonny Hammond]

The term coined after the Challenger disaster was normalisation of deviance.

It is pretty of obvious that to management these engine problems are being viewed in this manner.

I am sure when they are confronted with this type of allegation collectively they justify it all away......

Given that you guys actually FLY these things around in the middle of the night at 60 degress south, all the 400 drivers should individually write their safety concerns over this to the fleet manager, chief pilot and cc it to the ceo and board members.

NOW THAT WILL GET SOME ACTION!!!!
Sandilands will sprout that high and low...

[VC9]

Wasn't problems associated with obtaining environmental approval for the expansion of the engine shop (need for a new engine test cell) part of the reason for its closure.

[ALAEA Fed Sec]

They already had a test cell for these engines. May have had something to do with the Trent 900.

[LeadSled]

Going Boeing,

I can't tell you, after all this time, how many there were, the memory says three, it was only a small fleet.

These were just the double failures.

One, at least, was on descent into SFO from YVR, old mate of mine on his pre. or final Command Check.

The man from the FAA checked the fuel remaining very carefully, he could not conceive a double failure as being other than shortage of motion lotion.

RR lack of quality control was also the stuff of legend ---- who remembers the RB211-D5 main shafts that RR "forgot" to heat treat.

This "minor" QC lapse manifested itself as two fans falling in the Atlantic within about ten days, with "collateral" damage as they chewed their way out through the cowl. It transpired QF had five "soft" main shafts, only one already in an engine, none ever got onto a wing -- that was luck!

In the QF "Museum" at Sydney, amongst the display is a RB211 "step aside" gearbox, they were a common cause of failure right from the -22 on the Tri Star right through to the -524 on the B747-400.

Rather ironic this should be "featured" in the museum ---- probably because they had a few laying around internally damaged.

Of the engine failures I had of ( always near new) engines on the -400, two were this "traditional" gear train failure, leading to the oil/air separator failing, with the loss of all the oil contents within a short time. Forty or so years of this failure and RR still don't have a fix.

All this nonsense, over the years, caused QF ROS to institute 100% QC inspection, some of the things I have seen, I just can't conceive how they got into a parts box and got delivered to a customer.

Several were the times, over the years, that we ran out of pool engines, with the next QF, CX,BA or SAA failure resulting in the grounding of the aircraft until there was another engine available.

I would suggest that the present failure rate is a combination of the "normal" failure rate, plus QF being on the end of the list, because they can be disregarded by RR.

The ONLY reason QF set records of "on the wing" time with RB211, was because of the excellence of the output from the ROS engine shop ---- not because of RR. QF developed component lives are no no longer relevant, "wait 'till they break" is the order of the day.

The cost in service disruption is calculable, the cost of lost reputation less so.

QF learned the lesson, in very early days, that good maintenance was good business for an airline at the bottom of the world, with long thin routes.

Anybody who knew C.O Turner knew that he never spent a brass razoo on anything, unless there was a return ---- he understood the value of ROS --- the "expensive" QF maintenance was a big saving on the bottom line.

The present management knows the cost of everything, and the value of nothing.

Tootle pip!!

PS: T Green, the JT9 double failure of 16 in Sydney was a multiple bird strike.

[Ngineer]

I am sure our market share of the travelling public will continue it's downward sprial as long as incidents such as these keep happening. The only thing these beans counters can see is how to save a buck, not how to lose one.

Unfortunately these clowns will never learn from a smoking hole in the ground. The declining public perception of our safety will be our ultimate downfall and end. When the red rat fails, jackstar will follow suit shortly after.

[gobbledock]

The NASA program was always going to lose shuttles. I cannot recall the exact figures but I studied NASA risk management on the shuttle program back in the 80's. Even with the best mitigation of risk strategies the actual hull loss estimates were around 1 complete loss every 8 missions. They ended up losing 2 craft in around 300 missions. Again, my figures may be a little out but they are close.
Rollers and shuttles are two very different entities I agree, but risk management principles follow a similar path. The fact is that QF obviously don't perform very good risk management as evident by the amount of Roller failures they are encountering ?

[blueloo]

Steve can you post any pics of the latest failure ?

[Nemrytter]

gobbledock, the official figure from NASA was one loss per 100,000 flights. The unofficial (engineering) figure was 1 per 100 flights, which has been shown to be more or less correct.

The 'normalisation of deviance' term is very apt here (both Shuttle and Qantas). You can push things a little further each time there's a problem but eventually it's going to bite you, as happened with Challenger.

[ozbiggles]

It happened with both Challenger and Columbia. Issues that were known issues but had never caused a major issue until, well they killed people.
Space flight is a risky business, I think you have to accept that unknowns can kill your crews. The problem with these losses was that it was a known issue that wasn't dealt with before it had to have the opportunity to have the devastating effect it had.
Something can have a 1 in 100,000 chance, but it only has to happen once. Imagine what will happen to Qantas, RR, CASA if the next one to let go causes a major incident.
I've said it before but if Qantas was a cat, it would be very nervous at the moment.

[Sonny Hammond]

Stats are great at helping bean counters put a cost on safety for a risky exercise, like flying.

Really though, things are fifty/fifty.

They have or haven't happened.
They will or they won't happen.

Thats the reality for the crew and the passengers.

10 to the 7 chance of a hull loss is only good for the muppets in the office making the cost cuts.

[Sunfish]

"Normalisation of deviance", in a Qantas setting, is that the failure of one engine in a four engine aircraft is "routine".

It is, right up until the second engine fails. That is the lesson Feynman tried to inculcate - just because a double engine failure hasn't happened yet does not mean that it gets to be a more progressively remote possibility just because it hasn't happened.

This is exactly equivalent as believing that just because Zero has not come up on your roulette wheel for the past Five hours, it is never going to come up.

To put it another way, Wirthless will be in the middle of explaining away a single engine failure as "not a serious safety issue" - when her mobile phone will ring...........

[PPRuNeUser0171]

Another Rolls-Royce RB211 engine has failed on a Qantas 747-400 putting the airline in a difficult position if it decides to continue operating those jets across long oceanic routes to South Africa and the US before they can be modified.

The latest incident involved last night’s Johannesburg-Sydney flight carrying the Springbok Rugby team to the Tri Nation series in which they will play Australia in the opening match in a week’s time.

After abnormal vibrations and temperatures became apparent in its number 3 engine the flight turned back to Johannesburg about an hour into its long journey across the southern Indian Ocean, and Qantas is making arrangements for a replacement flight.

The safety issue is that there is a known fault in this engine type’s high pressure compressor units in which turbine blades can break free and cause severe damage both inside and outside of the engine. In one of a recent series of at least nine such failures in the Rolls-Royce RB211 version used on Qantas Boeing 747-400s one of them ruptured the engine casing on a flight that had just left San Francisco for Sydney last year.


Source: Qantas safety first claims in spotlight after engine failure | Plane Talking (http://blogs.crikey.com.au/planetalking/2011/07/16/should-qantas-ground-its-rolls-royce-engined-744s/)

[lomapaseo]

Obviously these events are newsworthy.

However my perspective is;

Every engine model has known defects which are addressed by a management plan that makes it extremely unlikely that harm will come to the passenger. Of course since any management plan entails some sort of inspections, and/or maintenance versus time interval there may be some incidents of a far less serious impact to the flight as benign as a single engine IFSD.

The latter are expensive and disruptive and as Qantas suggests an indicator of the need to review the timing of implementing corrective action.

My take is that the process being reported on in the papers is normal to the operation of a fleet and unlikely to play any significance to the greater majority of passengers

[Basil]

there is a known fault in this engine type’s high pressure compressor units in which turbine blades can break free
So is it compressor blades or turbine blades - or are they the same thing - bit like taxiways and runways :rolleyes:

[Oakape]

Haven't they already been down this path before, eventually ending up with QF1 in BKK? You know - we have been doing this for some time now & nothing has happened, so it must be safe. What a great idea it turned out to be, it's saving the company a fortune!

Isn't the definition of insanity doing the same thing over & over again & expecting different results? Perhaps they can't perceive the similarities or see the big picture. Someone needs to take a step back from the trees & take a look at the forest, before it's too late.

But then, that is working from the assumption that safety & a strong brand in the longer term is what management is striving for. And I'm not sure anymore that that is a valid assumption.

[bearfoil]

Compressor blades drive, Turbine blades are driven. imo,.

[bearfoil]

lomapaseo.

On the one hand, you state these 'events' are newsworthy. Then you conclude they are 'normal'.

[Best foot forward]

Other way round bearfoil, thte compressor is driven by the turbine.

[sb_sfo]

Think he was referring to the action on the air in the engine...

[bearfoil]

Arse about. The Compressor squeezes (works), the Turbine converts HP gas back to mechanical energy, which drives the other bits. So at the Blade(s) it's all in your 'perspective'?

What sort of kit carries your shafts?

[KBPsen]

Think he was referring to

Who knows what was referred to. The man is confused, as he so rightly admitted.

Another fine example of amphibology it is though.

[bearfoil]

confusion keeps me humble, sir. And tolerant of others.

[barit1]

Rushing to bearfoil defense, it depends on POV.

From an aero standpoint, bear's post #4 is exactly right.

From a mechanical standpoint, it's of course sdrawkcab.

:ok:

[Turbine D]

Perhaps this Pratt & Whitney video will answer the question of what drives what. Listen to the audio as the turbines and their roles are discussed.

‪How a jet engine works‬‏ - YouTube

I believe the failure of this engine, if it the same as the Qantas SFO engine failure, would be turbine blade failure related, not compressor blade related. The SFO engine failure was uncontained as well.

[bearfoil]

The earliest HPgas (jet) engines had piston engines driving the compressor, so the concept of drive/driven was established straightaway, imo. The thrust came from the exhaust. Long since retired, turbojets were noisy, wasteful, and high maintenance. So FANjets derive propulsion from the mechanical capture of the "exhaust", expressed in the Low Pressure Compressor (The Fan), which is driven by the Low Pressure Turbines at the back end. IMHO, and grateful to TD and barit1 to keep us all honest.

When a large wheel stops being driven, and starts to drive, bad things can happen. Worse things happen when drivers start to get driven (Turbine).
Or, a massive propellor in high Pitch in cruise that loses hydraulics and cycles to Low, (Flat) Pitch. Runaway Prop. Runaway Turbine. (Overspeed, nasty).

[Turbine D]

Hi Bear,

In a purist sense, be it a fan-less jet engine or a turbo fan engine, the turbine or turbines drive the compressor or compressor/fan combination. The only time the compressor or compressor/fan combination "drives" is during the start operation. Here, the compressor or compressor/fan combination through an auxiliary energy source initiates rotation, driving the turbine/turbines while compressing the air delivered to the combustor. When the combustor delivered air pressure is sufficient, fuel flowing into the combustor is ignited. From that point onward, the turbine/turbines drive the compressor or compressor/fan combination.

Hope this clarifies this discussion.

[ironbutt57]

In fact, one will regularly see a negative EPR (measured from inlet to outlet N1} when an RB-211 is at flight idle during descent, meaning the fan is being driven by inlet airflow, as opposed to gaseous outflow from the combustor....never heard it to be an issue, as the intermediate, and hi pressure compressor were absorbing the load and keeping the gas path flowing in the "right direction"..

[barit1]

Here is my take (http://www.pprune.org/rumours-news/425863-qantas-emergency-return-ksfo-explosion-engine-6.html#post6025413)
on the QF74 failure of 31 Aug 2010 (744 SFO). I haven't heard any final word on that event, however.

[Joetom]

Qantas speeds up RB211 programme (http://www.flightglobal.com/articles/2008/05/23/224064/qantas-speeds-up-rb211-programme.html)
.
This item was May 2008.

Too many headlines, too often ???

[qf 1]

next time Qantas roll out that old chest nut of WORLDS BEST PRACTICE i think some one needs to ask for the definition,it may high light a few of the problems Qantas are going through at the moment.

[golfyankeesierra]

This item was May 2008.

Too many headlines, too often ???

Makes one wonder, why the ... did they take them on their A380 as well?
Bit stubborn them aussies?

[MountainBear]

My take is that the process being reported on in the papers is normal to the operation of a fleet and unlikely to play any significance to the greater majority of passengers

That's true of course and utterly beside the point.

Too many headlines, too often ???

That's the point.

The general public are not safety experts. Perception for them is often reality. And if there is a growing perception among the general flying public that Qantas has a problem, it has a problem.

[bearfoil]

So the secret is to manage risk, shower the mushrooms with BS, and act as if it is not a thang..........Say, what about that duff stub pipe, Hans?

If the non-public, the Pros, engineers, and safety guys think there is a problem, that is a Horse of a different Hue. And kudos to PPRuNe.

I kind of hope no one reads this, but I will say this. A loss of airspeed reads is nothing to manage as/if...... Neither is teaching the wrong things to do at STALLWARN. Allowing suspicions to fester on the Hull while the industry changes out (got a "round tuit"?) seemingly "redundant" probes is another thing. "Marginal" service life of TurboFans onwing is another. Maybe the Public isn't so dumb after all?

Fortunately, there are no orphanages or hospitals any where near TASIL.


TD. Well, you are exactly right. I need the works in a word, however, and I know turbine can no drive unless it is also driven. No free lunch?

[Turbine D]

Thanks Joetom,

I was unaware of the compressor blade situation.

[LAME2]

Not 767 mate. The short 767 transits mean the compressor case doesn't cool down between flights. It is about the blade tip clearance.


Is this why no-one seems to be concerned with the EDTO effects of these engine failures?

Before you get upset with this question, I realize EDTO for B747 does not come into effect until 2015, however engine failures at an airline where that same engine is used on B767 twins, supposedly maintained to EDTO standards, it appears to me no-one is counting these failures in their IFSD rate calculations.

I would have thought they would have figured somewhere in their statistical analysis for EDTO. Are QANTAS still swapping engines between B767 and B747 like they used to many years ago?

[Keg]

I would have thought they would have figured somewhere in their statistical analysis for EDTO. Are QANTAS still swapping engines between B767 and B747 like they used to many years ago?


When was this? The mid '80s with the 767-200s?

As far as I recall, the Rollers on the current 767s are not the same as those on the 744 and we got the first Roller 767 in 2001/02. Therefore they've never been swapped. The CF6s on the 300s are not the same as the CF6s on the 744s and they've never been swapped. That only leaves the Pratts that were on the 767-200s and I'm not sure what 'overlap' there was from when we got the first 767-200 in about the mid 80s and Pratt engined jumbos.

[Mach2point7]

It is worthwhile reading the ATSB report released in May 2011 reached at the link below.

The latest fix for this ongoing HPC stage 1 blade problem is SB RB211-72-GO36 which was issued in Feb 2009. This covers revised geometry blades.

At the time of issuance of the report, only 18% of QF's engines had this SB incorporated. At that time there was no apparent urgency to implement the SB, but the SB would be incorporated when other work was required on the HPC:

"The operator is continuing to embody SB RB211-72- G036, issued in 2009, at engine shop visits where the HPC module is removed. However, should the rate of failures increase significantly, a review of current modification policy will be undertaken."

I don't know if the failure rate has increased significantly. But the perception is that it has, certainly more than the 0.8 events per year predicted by RR and quoted in the ATSB report.

The question remains as to whether QF has increased the pace of SB implementation since then.

If QF has not voluntarily sped up the SB implementation, then CASA needs to urgently review this case.

http://www.atsb.gov.au/media/3422442/ab2011040.pdf#page=9

[Flugbegleiter]

I don't know if the failure rate has increased significantly. But the perception is that it has, certainly more than the 0.8 events per year predicted by RR and quoted in the ATSB report.

So does anyone know how many times this has occurred this year and last? I know of at least 4 last year, but I am sure it was more than that:

March 2010: QF5 SYD-SIN VH-OJ?
April 2010: QF1 BKK-LHR VH-OJF
September 2010: QF74 SFO-SYD VH-OJP
November 2010: QF6 SIN-SYD VH-OJD

I haven't even bothered to keep track this year. I was cabin crew on board one of these flights and let me tell you, it can be quite a scary event. These failures can be pretty spectacular. When you're only 800 feet off the deck and the entire cabin is lit up bright orange from an engine that has just "exploded", the last place you want to be in in the air.

[Runaround Valve]

The P&W engines on the B747 and B767 were not interchangeable. They were like chalk and cheese. 747 has cable driven air operated fan reversers, 767 was hydraulic with screwjacks. Cowlings different on both types, 767 was of the FADEC thrust era wheras the 747 was manual. Instructor told us that the engine overhaul shop found only seven parts that were interchangeable between the engine models.

[Nepotisim]

RB211's are interchangeable between the 747 & 767. Three mechanical items, data plate and rating plug. Has to be tested to 'H' standard at the build stage which they mostly are.

CF6's can be interchanged too, but only with the one and only FADEC 767.:ok:

[Sunstar320]

Hello.....

http://farm7.static.flickr.com/6123/5948551121_2c7ca4af26_z.jpg

[whatdouknow]

From what I hear an Avalon Manager stated that there were high vibes during an engine run on 3 x 'ER' engines and that his facility was too blame...

Someone also apparently denied this and suggested that it was more to do with many, many layers of lube still covering the blade roots and spinner on arrival...

Is the Manager hiding something by blaming those that are not guilty?

[Cargo744]

An "ER" has GE engines

[whatdouknow]

Thanks Cargo744... think it is that funny Red coloured one if that is the case.
Removing all of the lube and then re-applying it once apparently caused high vibes on 3 engines

[TIMA9X]

Qantas dismissed claims that the engine had exploded as incorrect.


But Mark Sowerby, a passenger on QF64, said he saw flames shoot from the rear of one of the plane's engines for several seconds before they were extinguished.
''Contrary to the Qantas spin on events, the number three engine near the exit row I was seated in blew up,'' the Brisbane businessman said yesterday.
Mr Sowerby said that at a hotel in Johannesburg he witnessed staff being told not to use the word ''explosion''. my bold

Read more: Qantas denies engine exploded (http://www.smh.com.au/travel/travel-news/qantas-denies-engine-exploded-20110718-1hlo2.html#ixzz1STBPGoGU)

This is back in the news again today,
whether it exploded or not, I found this quote interesting from another thread,
I hear the engine that failed on the weekend with the Sprinboks onboard was over it's maximum number of allowable cycles before maintenance and that very special mod it required. Anyone care to ring 3AW tomorrow with a rumour that JL required an engine change after 420 cycles however it blew up one hour out of J'Burg on cycle number 431?
by Steve P, ALAEA Fed Sec

spin time Ooh W?

[Flugbegleiter]

While ever this problem continues to exist Qantas should use only 747-400ERs or 747s with modified engine to fly routes like SYD-JNB and SYD-EZE. It's not worth the risk of something going wrong 5 hours from land...

[LAME2]

The P&W engines on the B747 and B767 were not interchangeable

RB211's are interchangeable between the 747 & 767. Three mechanical items, data plate and rating plug. Has to be tested to 'H' standard at the build stage which they mostly are.

Thanks all.

I guess it is this confusion which results in people not counting these failures into the EDTO statistics. Both are a RB211-524 (G for B747 and H for 767).

Perhaps suffice to say, it all relates to demise of the Sydney Engine Overhaul facility and what they could do before and what they seemingly cannot do now.

[Engineer_aus]

Keg, VH-OGV is the only 767 with Fadec, so that engine is swapped with the GE 744's that are GE powered, all the other 767's are PMC

As for RR, they are having IFSD all around the world. We have seen the A380, B744, B717 all RR powered. One would and should be asking what is happening at RR. It is unfortunate that Qantas aircraft are in the media with these shutdowns, however they all have managed to land safely. As for what to do, it is a mere massive task to pull these engines and send them off. I personally would be upping my boroscope inspections and anything that is getting close to drop the engine. I know RR are pretty liberal in there allowances and not only myself but my fellow engineers have raised our eyebrows in some of their decisions.

As for Swapping the 767 and 744 engines around, are they not different mod status ie G,GT,GH thus not allowing them to be swapped between the fleet?

[neville_nobody]

Geoffry Thomas is on to it in ATW. No mention of them shutting down their own engine overhaul shop though.

Qantas to speed up RB211 engine modifications on 747 fleet | ATWOnline (http://atwonline.com/aircraft-engines-components/news/qantas-speed-rb211-engine-modifications-747-fleet-0719)


Qantas to speed up RB211 engine modifications on 747 fleet

Qantas will fast-track modifications of Rolls-Royce RB211 engines powering its Boeing 747-400 fleet to stem failures caused by cracked high-pressure compressor blades, of which the airline has suffered three this year and two late last year (ATW Daily News, Nov. 8, 2010).

The engine manufacturer has acknowledged the problem, caused by a distortion of the compressor case resulting in the tips of fan blades cracking and disintegrating.

Rolls issued a service bulletin regarding RB211 HPC blades in 2006 but in 2009 opted to redesign the blades. QF has modified 25% of its fleet and is also looking at altering the way the carrier operates its 747s as other airlines do not have the same failure rate. QF's RB211 failure rate is three times the industry average.

[TIMA9X]

The aftermath,
Jet engine explosion can ruin your day (http://www.smh.com.au/opinion/society-and-culture/jet-engine-explosion-can-ruin-your-day-20110801-1i849.html)
HECKLER
http://images.smh.com.au/2011/08/01/2530010/art-353-0211-dinalie-200x0.jpg Illustration: Dinalie Dabarera



Jet engine explosion can ruin your day

I TELL you what makes my blood boil - it's when the engine explodes after take-off.
There you are on the trip of a lifetime to Europe, in business class (thanks to frequent flyer points), although actually securing a business-class seat with points is a heckle all of its own. So having beaten that challenge, it was with a sense of smug satisfaction that I reclined my seat, a gin and tonic in hand, as we took off from Bangkok for the final leg to London.
The explosion that rocked the plane was followed by a deathly silence.
Advertisement: Story continues below
I'm not a nervous flyer, but I became a little worried at that point. The captain announced that we had ''engine trouble''. (A distinct advantage of business class is you can't actually see the fireball and flames). We then had to fly to a zone to dump all the fuel before landing. This takes an hour. The captain assured us he had done this before on a simulator. He also assured us the emergency services vehicles we would see along the runway were standard procedure. Of course they were.
Once landed, we had to wait a further hour and a half on the runway while Qantas negotiated immigration for a plane full of passengers. But don't expect this to make any difference. The official asked what my intended address was in Thailand, and, as I looked at him blankly, would not allow me in.
The airport was empty save for a straggly queue of weary refugees, all with no address. So, none of us were allowed through.
Eventually, some official waived the condition and we collected our bags and were shipped off to a hotel arriving, exhausted, just before dawn.
No new aeroplane was flown in. Instead we were bumped onto other flights. We were kindly offered a flight to Tokyo. I pointed out that we were actually hoping to go to London.
Eventually, we agreed to go economy so as to arrive in less than three days.
No air miles were refunded. No concessions were made. All dreams of business-class luxury, sleep and gin and tonics receded. Connecting flights were missed. The trip of a lifetime was fast becoming a nightmare.
But not to worry, we had a lovely long holiday before we had to contemplate the flight home.
Except you won't believe what happened on the way home. The plane broke down, in Hong Kong this time. Another trip back and forth through immigration. Another night in a hotel. Another great experience with the ''Spirit of Australia''.
Clare Taylor





The consequences of the management decision to run down the engineering division at Q. The writer coped it both ways on her dream trip to Europe. Says it all really.

[BigGun]

While ever this problem continues to exist Qantas should use only 747-400ERs or 747s with modified engine to fly routes like SYD-JNB and SYD-EZE. It's not worth the risk of something going wrong 5 hours from land...

They only ever send ER's to EZE as it is, JNB is generally the roller.

[Captain Gidday]

Just for the record, the reason only the GE engined 400ERs go to Buenos Aires has nothing to do with engine reliability.
Anyway, I have no qualms being in any 747 a long way from the Nearest Suitable [and do so every time I go to work]. For one thing, you still have three engines after a failure, a much safer situation than in the 777 many of you idolise. [Please don't get me wrong. I like the 777 too - just not down near McMurdo Sound in the middle of winter, 2400 miles from the nearest place to land, on one engine].
Also, all the failures in this sequence that I know of, and I think I know of them all, have been fairly soon after takeoff thrust has been reduced in the climb. It seems when a blade has had enough and breaks, it is always then and not at some random point in the cruise, miles from anywhere.
Not like another RR211 sequence of failures I can think of years ago that occurred randomly in cruise, climb, descent and at least one in THAT sequence on taxy at idle thrust.

[Waqavukatau]

Good point. However, the last place I'd rather be . . . suddenly on the ground!

[Captain Gidday]

Hey, nice moniker, Waqavukatau. My wife is Kai Viti so she translated it for me.
Where I used to fly though, we'd have to call you 'Balus'!
Keep on truckin' :ok:.

[frangatang]

Funny how BA dont seem to have the same problems with their RR engines!

[Jetsbest]

A small point of order.
While I don't know the exact 777 EROPS rules, I think you'll find that 180minutes would keep the aircraft always within 1200-1300 miles of an adequate airport, and even 215 minutes would keep it within 1600 miles.
In short, nothing should place a twin-engined jet 2400 miles from an airport. :ok:

[Captain Gidday]

Yes Jetsbest, technical point to you - you are quite correct that a 777 would not be down in Antarctica due to EROPs limitations [Ask V about that on their short lived MEL-JNB service].
This is going to be quite a problem in the future. What is going to replace the 747-400? A380? [Too big]. A340-500 [probably too inefficient] 747-800 [maybe, if you want to stay with essentially 45 year old technology].
There isn't an easy answer. Close down all those long over water remote routes is one option.
Anyway, back to engine failures -
As the Old Guys in Qantas used to say [and some of us still do]:
"Why do I stick to flying four engined aircraft?
Because Boeing doesn't make five engined aircraft!"
[OK, don't get technical on me. We are not likely to see any B52s in airline colours].
Of course, flying four rather than two, you've automatically doubled your chance of having an engine failure, all other things being equal.
Point of order Frangatang: BA and CX have both had failures of this type - just not as many. This fact is currently very much exercising the minds of the Second Smartest Guys in the Room [the Smartest Guys in the Room being fully occupied worrying about you Ppruner's, apparently].

[RATpin]

CG.the reason ETOPS changed to EDTO is that it is no longer about engine reliability (unless your talking Qantas Rollers)and all about cargo fire suppression.There is no longer a point of difference between twin/triple/four from the point off view of the international overseeing body.

[kiwi grey]

Capt Gidday said
"Why do I stick to flying four engined aircraft?
Because Boeing doesn't make five engined aircraft!"

If I remember correctly, this was originally attributed to a former Chairman of Rolls Royce - except he said 'they' instead of 'Boeing'.
Coming from the maker of the said engines added a certain piquancy to the remark :E

[fruitloop]

Hmmm No commercial B52's....Dammm

[Captain Gidday]

There is no longer a point of difference between twin/triple/four from the point off view of the international overseeing body.
Ratpin, CASA Aviation Advisory Publication 82-1 'Extended Diversion Time Operations' published July 2007 states :

Operators of aeroplanes with more than two engines operating on EDTO routes, in passenger carrying
operations must comply with the operational and process requirements specified in the EDTO rules in CAO 82.0 from the 1st July 2015.
[Para 7.3.1]