Archive for the ‘Engineering’ Category

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Emergency Airworthiness Directive issued for Trent 900

November 11, 2010

The European Aviation Safety Agency have released Emergency Airworthiness Directive (EAD) 2010-0236-E requiring operators of Trent 900 engines to perform inspections of their engines.

The Directive is applicable to the following engine variants: RB211 Trent 900 series engines, variants RB211 Trent 970-84, RB211Trent 970B-84, RB211 Trent 972-84, RB211 Trent 972B-84, RB211 Trent977-84, RB211 Trent 977B-84 and RB211 Trent 980-84, all serialnumbers.These engines are known to be installed on, but not limited to, AirbusA380 series aeroplanes.

Reason: An uncontained engine failure has recently occurred on a Rolls-RoyceTrent 900 involving release of high energy debris and leading to damage to the aeroplane.Analysis of the preliminary elements from the incident investigation showsthat an oil fire in the HP/IP structure cavity may have caused the failure ofthe Intermediate Pressure Turbine (IPT) Disc.This condition, if not detected, could ultimately result in uncontained engine failure potentially leading to damage to the aeroplane and hazardsto persons or property on the ground.For the reasons described above and pending conclusion of the incidentinvestigation, this AD requires repetitive inspections of the Low PressureTurbine (LPT) stage 1 blades and case drain, HP/IP structure air buffercavity and oil service tubes in order to detect any abnormal oil leakage,and if any discrepancy is found, to prohibit further engine operation.The requirements of this AD are considered as interim action. If, as a result of the on-going incident investigation, a terminating action is later identified, further mandatory actions might be considered.

Required as indicated, unless accomplished previously:

(1) Within the compliance times indicated in Table 1 of this AD, accomplish the following actions in accordance with Rolls-RoyceNon Modification Service Bulletin (NMSB) 72-AG590, Par 3. Accomplishment Instructions, 3.A or 3.B as applicable to the engine configuration:

(1.1) Carry out an extended ground idle run.

(1.2) Inspect the Low Pressure Turbine (LPT) stage 1 blades andcase drain.(1.3) Inspect the HP/IP structure air buffer cavity and oil service tubes.

(2) If any discrepancy is found during the inspections required by paragraph (1) of this AD, any further engine operation is prohibited. Within one day after the accomplishment of the inspection, report the findings to Rolls-Royce.

(3) Inspections accomplished in accordance with the content of NMSB72-AG590 before the effective date of this AD, are acceptable to comply with the initial inspections required by this AD.

(4) After the effective date of this AD, do not operate an engine on an aeroplane unless it has been inspected in accordance with the requirements of this AD.

The Aviation Herald points out that:

An oil fire possibly similiar to the Qantas Trent 972 led to an uncontained engine failure of a Trent 772 engine on Edelweiss’ Airbus A330-200 registration HB-IQZ near Miami, see Final Report: Edelweiss A330 at Miami on Oct 5th 2003, uncontained engine failure during departure. In their safety recommendations released in December 2006 following the conclusion of the investigation the NTSB wrote:

“Disassembly of the No. 1 engine revealed evidence of heat damage and distress in the HP/IP turbine bearing chamber consistent with the presence of an oil fire. Microstructure examination of the fracture surfaces on the IP turbine disk drive arm revealed damage consistent with a localized fire that caused the drive arm to eventually fail and separate, allowing the IP turbine disk to overspeed. The overspeed condition resulted in the liberation of all IP turbine disk blades through the IP turbine case, with some blades striking the airplane. Because thermal damage within the HP/IP turbine bearing chamber and associated hardware prevented identifying the exact cause of the fire based solely on the physical evidence from the No. 1 engine, the No. 2 engine was examined to help establish possible causes or contributors to the bearing chamber fire in the No. 1 engine.

A borescope inspection of the No. 2 engine revealed that the HP/IP turbine bearing chamber internal vent tube was obstructed with a black substance. An airflow check of the vent tube revealed that the air passage was not completely blocked. A nondestructive three-dimensional neutron tomography analysis revealed that the substance was not solid and was characterized by nodules of carbon deposits (also known as coke) with areas of voids. Although coke formations within oil tubes are not uncommon, the morphology, amount, and location of the carbon deposits found in the vent tube of the No. 2 engine were unusual and inconsistent with coke formation seen on other Trent engines or from other service experiences.”

The NTSB had concluded in April 2006 the probable cause of the Trent 772’s failure was:
“the coking (carbon build-up) in a vent tube which led to a fire and the subsequent liberation of the IP turbine blades. Contributing to the cause of the uncontained engine failure was the absence of measures to adequately monitor the in-service performance of a new engine/oil combination.”

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Posted in Aviation, Engineering, Technology | 2 Comments »

Son of Hubble may not launch till after 2015

November 11, 2010

Earlier this year it became clear the the son of Hubble the James Webb Space Telescope, was late and over budget. Costs had ballooned to 5 billion dollars (from the earlier 3.5 billion dollars) and launch was expected in 2014. It has now been acknowledged that costs will be not less than 6.5 billion dollars and launch even in 2015 is optimistic. The management is now being changed and reorganised.

The BBC has the story:

The scale of the delay and cost overrun blighting Nasa’s James Webb Space Telescope has been laid bare by a panel called in to review the project. The successor to Hubble will probably cost at least $6.5bn to launch and operate, and may get into orbit by September 2015.

But even that assessment is optimistic, say the panel members. The head of the US space agency has accepted that “cost performance and coordination have been lacking”. Charles Bolden has ordered a reorganising of the project and has changed the management at its top. Estimates for JWST’s total cost to build, launch and operate have steadily increased over the years from $3.5bn to $5bn. Along with the cost growth, the schedule has also eroded.

The most recent projected launch of 2014 has looked under pressure for some time. The independent panel chaired by John Casani of Nasa’s Jet Propulsion Laboratory (JPL) in Pasadena, California, believes it to be unrealistic. The group was convened to examine the root causes of JWST’s problems. It found the original budget for the project to be insufficient and poorly phased, and blamed the management for failing to pick up and deal with the issue.

“This is a very large complex project and to estimate something with any real degree of precision that’s never been done before is a tough job,” John Casani told reporters. “But the bottom line is that there was never enough money in the budget to execute the work that was required. The panel did however commend the technical success of the project. Mr Casani said the technology on JWST was in “very good shape”. The telescope was always regarded as major undertaking. Its primary mirror is 6.5m (21ft) across – close to three times wider than Hubble’s. The huge reflector will sit behind an even more expansive sun shield, the area of a tennis court. This structure will protect the observatory from radiation from the Sun and the Earth. Whereas Hubble sees the Universe mostly in visible light, JWST will observe the cosmos at longer wavelengths, in the infrared. It will see deeper into space and further back in time, to the very first population of stars.

When it is finally built, it will be launched on Europe’s Ariane 5 rocket and sent to an observing position 1.5 million km from Earth. It is expected to have a 10-year lifespan. Its distance from Earth means the telescope cannot be serviced by astronauts, as was the case with Hubble.

Herschel (BBC)

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Now Boeing 787 Dreamliner delayed by fire on test flight

November 11, 2010
2nd Boeing 787 First Flight

First flight of Boeing 787 No.2: Image via Wikipedia

An electrical fire could have a myriad of causes and does not necessarily have any fundamental design implications, but the Dreamliner does not need further delays even for fairly trivial faults.

The Press Association reports:

Boeing has grounded its test fleet of new 787 passenger jets while it investigates an electrical fire that forced one of the planes to make an emergency landing. On Tuesday, a 787 on a six-hour test flight had to make an emergency landing in Texas after the crew reported smoke in the rear of the plane.

Boeing said it would take several days to analyse flight data and stopped flights for all of its 787 test planes “until we better understand the cause of the incident”. Spokeswoman Loretta Gunter said it is not yet clear how long it will be until test flights resumed. “We don’t have a schedule in mind right now,” she said.

The company plans ground tests on the planes while they are not flying.

Ms Gunter said the fire started in a power control panel in a rear electronics bay on the test plane. Boeing is inspecting the power panel and the area around it to see if other repairs are needed. The fire cut the plane’s electrical power. Boeing said back-up systems including a ram air turbine – essentially a wind-powered generator – functioned as expected.

The Federal Aviation Administration is investigating Tuesday’s incident and the National Transportation Safety Board is monitoring the situation but has not sent investigators to the scene.

It is the latest setback for a plane that is already about three years behind schedule. Boeing had hoped to deliver the first 787, which it calls the Dreamliner, to Japan’s All Nippon Airways in the first quarter of next year.

“We are committed to finding the cause quickly but will not rush the technical team in its efforts,” the company said.

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Rolls Royce faces 3 different engine issues as Singapore Airlines changes engines on 3 A 380s

November 10, 2010

It seems that Rolls Royce are facing  issues with three different engines; the Trent 900 for the A380s, the RB211-524s having Trent features and the Trent 1000.

Singapore Airlines are grounding three of their A380s for engine change-outs as a precautionary measure.

AFP:

Singapore Airlines (SIA) said Wednesday it had grounded three Airbus A380 planes to carry out “precautionary” engine changes following a mid-air engine failure on a Qantas-operated superjumbo. “Based on further analysis of inspection findings as the investigation into last week’s incident involving another operator’s Airbus A380 is progressing, Singapore Airlines will be carrying out precautionary engine changes on three A380s,” the carrier said in a statement.

An SIA spokeswoman told AFP that Rolls Royce had advised the carrier to change the engines after tests showed oil stains on them. “We were advised by Rolls-Royce in particular that these three engines had signs of oil stains,” she said, stressing the issue was different from the problem that affected the Qantas A380 plane last week.

The three planes are now in London, Sydney and Melbourne pending the engine changes, and SIA could not confirm the duration of their grounding nor the cost of replacing the engines.

My simplistic view of what is certainly a very complicated picture is that there are certain operating conditions at which the Trent 900 is subject to oil leaks (possibly because some oil carrying pipes are susceptible to vibration based cracks). These operating conditions are probably when the Trent 900 is being “pushed” close to maximum thrust conditions and Qantas’ method of operation has these engines operating at these conditions for more of the time than other airlines. This mode of operation probably occurs more often at or soon after take-off.

Even though Rolls Royce has said that the issues with the Trent 1000 are entirely different and have been fixed, there remains the issue of whether the Trent based improvements when introduced into the RB211-524 engine also creates a “dangerous” operating zone.

It seems to me that Rolls Royce is wrestling with at least 3 different engine issues:

  1. with the Trent 900 for the A 380’s, especially at high-thrust conditions which Qantas uses more than other airlines,
  2. with the RB211-524 (xT) where the (T) represents the use of Trent features and used mainly in Boeing 747-400’s, and
  3. with the Trent 1000 for the Boeing Dreamliner where some issues have been fixed but where delays are still in the air.

I have no doubt that they are going to get fixed but the direct cost will be high and my guess is that Rolls Royce will have to bear the brunt of the cost with some costs incurred by Qantas for their own fleet. It will need the sale of many Trent 900s before Rolls Royce can amortise all the development and “teething” costs for this engine. It is of some small comfort that the number of engines to be “fixed in the field” is relatively small. The costs for Airbus will be mainly indirect for the loss of reputation and for some lost opportunities. But the A 380’s ability to land safely even after one wing was heavily damaged is not unimpressive.

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Damage to Qantas A380 aircraft was more severe than thought

November 9, 2010

The Australian:

New suggestions have emerged that a spectacular engine failure near Singapore last week caused more damage to the plane involved than first thought. The No 2 engine’s violent disintegration ripped a hole through the Airbus A380’s left wing, destroying wiring that prevented the pilots from turning off the No 1 engine and causing a fuel leak. Suggestions have now emerged that there was also significant damage to hydraulic systems that prevented spoilers, panels on the wing that create drag to slow the plane down, from deploying.

 

The wrecked engine after the plane landed in Singapore.

The wrecked engine after the plane landed in Singapore.

 

The suggestions came as the Australian Transport Safety Bureau yesterday interviewed the flight crew of the stricken A380 and performed the first boroscope inspection of the Rolls-Royce Trent 900 engine. Investigators are continuing their search for the rest of a turbine disc that broke up in the incident and have set up a schedule for examining a recovered piece that has been sent to Britain for forensic tests.

Inspections of the grounded planes continued yesterday amid suggestions European regulators were poised to issue an airworthiness directive on the checks.

With this amount of damage to the wing it is a tribute to the pilots and to the Airbus A380 aircraft that the landing in Singapore was as smooth as it was and with no injuries at all.

Rolls Royce has said that the issues are specific to the Trent 900 and there are further indications that the issues may be specific to the engines as used by Qantas.

Meanwhile

Rolls-Royce says that the uncontained engine failure on a Qantas Airbus A380 en route from Singapore to Sydney on November 4 “is specific to the Trent 900. We can be certain that the separate Trent 1000 event which occurred in August 2010 on a test bed in Derby is unconnected,” Rolls-Royce said in a statement yesterday. “This incident happened during a development program with an engine operating outside normal parameters. We understand the cause and a solution has been implemented.”

The engine maker added that it would provide a further update on the investigation with its interim management statement on November 12.

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Qantas pushes its Trent 900 engines harder than other airlines

November 9, 2010

It would seem that while there may well be a fundamental issue with the Trent 900 as used by Qantas, the manner in which Qantas operates the engines may be a significant contributing factor. Sources indicate that Qantas run their engines “harder” than the other Trent 900 users (Singapore Airlines and Lufthansa) primarily, it seems, for economic reasons. Competitive pressures on airlines as well as those on the engine makers may be coming into play.

Reuters:

 

Qantas cracking the whip too hard? (image:aerospaceweb.org)

 

Qantas Airways  is reviewing the way it operates its A380 planes after last week’s engine blowout, a source said on Tuesday, amid reports that it worked its Rolls-Royce  engines harder than other airlines.

Qantas operates its A380 engines at higher thrust levels, which could result in resonating vibrations that cause oil lines to crack, The Australian newspaper said. The higher maximum thrust setting is used on some Qantas A380 take-offs on long-haul routes between Los Angeles, Sydney and Melbourne than other operators such as Singapore Airlines, the daily said, quoting unnamed engineers. However, the extra thrust setting of 72,000 pounds remained 3,000 pounds below the engine’s design limits and within operating guidelines, it added.

Chief Executive Alan Joyce said on Monday that its engines had a “slightly higher level of power” than those used in Singapore Airlines or Lufthansa planes, but they were certified to operate at those levels. The way Qantas operated the engines was part of a wider review, said an airline source, who was not authorised to talk publicly about the matter. “The operations are one of the things Qantas are reviewing along with the components,” said the source.

Qantas, which declined to comment on the report, said on Friday it suspected a material failure or a design issue may have caused last Thursday’s engine failure over Indonesia which forced the aircraft to make an emergency landing in Singapore.

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Rolls Royce honing in on problem: share price slide halted

November 8, 2010

It seems that Rolls Royce are honing in on the A380 problem which seems to be specific to the Trent 900 engine (and perhaps just the Qantas Trent 900 engines) and unconnected with the earlier test bed incident on a Trent 1000. The share sell-off which continued on Monday morning was halted and the share price had recovered somewhat by the end of the trading day in London.

StockMarketWire.com

Rolls-Royce is to carry out a series of checks on Airbuses powered by its Trent 900 engine following an engine failure on a Qantas flight last week.

 

RR share price on Monday November 8th: moneyam.com

 

Rolls-Royce said it had made progress on the cause of the failure and it was now clear the incident was specific to the Trent 900 engine.  It said: “As a result, a series of checks and inspections has been agreed with Airbus, with operators of the Trent 900 powered A380 and with the airworthiness authorities.
“These are being progressively completed which is allowing a resumption of operation of aircraft in full compliance with all safety standards. “We are working in close cooperation with Airbus, our customers and the authorities, and as always safety remains our highest priority.”
Rolls-Royce adds: “We can be certain that the separate Trent 1000 event which occurred in August 2010 on a test bed in Derby is unconnected.  This incident happened during a development programme with an engine operating outside normal parameters. We understand the cause and a solution has been implemented.”
It said the Trent 900 incident was the first of its kind to occur on a large civil Rolls-Royce engine since 1994. Since then Rolls-Royce has accumulated 142 million hours of flight on Trent and RB211 engines.

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Divabot – debut for the all singing, all dancing robot

November 8, 2010

(PhysOrg.com) — A singing, dancing humanoid recently joined a live group of dancers to perform.

Developed by the country’s biggest public research organization, Japan’s National Institute of Advanced Industrial Science and Technology (AIST), the new variant of HRP-4, the female robot HRP-4C deemed “Divabot,” has a realistic face, movable features and even mimics human-sounding breaths.

Diva-bot’s intricate software creates complicated movements such as jumping, dancing and even balancing. Using a mouse, those with zero robotic expertise are meant to find Diva-bot easily operable, which may or may not be a good thing considering how complex the robot is.Comparable to the software commonly used in CG character animation, Diva-bot’s positioning can be controlled by clicking on the different parts and dragging them to the desired position, creating a sequence of key poses that the software generates, making the robot move.

http://pinktentacle.com/2009/03/video-hrp-4c-fashion-model-robot/

 

HRP-4C fashion model robot --

Divabot: image http://pinktentacle.com

 

The HRP-4C, a walking, talking humanoid fashion model fembot developed by Japan’s National Institute of Advanced Industrial Science and Technology (AIST), is ready for the runway.

Video here.

With 30 motors in her body, the 158-centimeter (62-in) tall, 43-kilogram (95-lb) HRP-4C can walk around and strike a range of poses.

The black-haired robot also has 8 motors in her face, allowing her to wow the crowds with expressions of simple emotions like anger and surprise.

 

 

HRP-4C fashion model robot --

Anger // Surprise: HRP-4C

 

 

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Something amiss with the Qantas version of the Rolls Royce Trent 900 engines

November 8, 2010

Singapore Airlines has just announced, according to Reuters, that it had completed engine inspections on all its Airbus A380 aircraft and did not find any issues of concern.

“We have completed the engine inspections on all our A380 aircraft and did not find anything of concern,” SIA spokesman Nicholas Ionides said on Monday.

“The findings of the inspections have been reviewed with Rolls-Royce. Any further checks that may be recommended by the manufacturers will of course be done, and in the meantime we continue with our regular routine checks.”

Meanwhile,

Australia’s Qantas said on Monday it would keep its A380 fleet grounded for at least another 72 hours after discovering problems on three more of the superjumbo’s engines.

Singapore has 11 A 380s powered by Rolls Royce Trent engines while Qantas has 6 Airbus A 380s. The Wall Street Journal reports:

Qantas Airways Ltd. on Monday said its engineers found oil leaks in Rolls-Royce Group Ltd. engines on three of its grounded fleet of A380 jetliners, amid an investigation into the blowout of a turbine that forced one of its double-deck superjumbos to make an emergency landing in Singapore last week. “These engines are not performing to the parameters you would expect,” said Alan Joyce, chief executive of Qantas, in a press conference in Sydney. “The oil leaks were beyond normal tolerances.”

Mr. Joyce added that the Rolls-Royce Trent 900 engines that Qantas operates on its fleet of A380s are designed to provide more thrust and torque, and that this version of the turbine could be at fault. Engineers have identified oil leaks on engines from three separate Qantas A380s, one currently grounded in Sydney and two other aircraft in Los Angeles, he said.

Mr. Joyce said that Qantas uses a different design of Trent engine than those used by Singapore Airlines and Deutsche Lufthansa AG on its A380s.

The problem seems to be narrowing down to either the particular version of the Rolls Royce Trent 900 engine used by Qantas or the particular maintenance regime or procedures applying to the Qantas engines. In either case it should be of some cheer to Rolls Royce that the problem may not – on the surface – be a generic design fault with the Trent engines but something restricted to the engines as used by Qantas.

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Posted in Aviation, Engineering, Technology | 3 Comments »

Reality check: Orders for wind turbines to fall by 93%

November 8, 2010

Reality and common sense are returning to dampen the mad rush to wind power. The fact that connecting intermittent power sources to the grid is a source of dangerous instabilities and that intermittent power sources do not actually contribute to any secure generating capacity are bringing a “cap” into play. Following the drop of orders in the US, the UK is also expecting sharp reductions in installations.

From The Guardian:

Britain recently overtook Denmark to become the world’s largest offshore windfarm player, implying the tripling of capacity in the next two years. But new projects will dry up in 2013. Only 90 megawatts (MW) of newly installed capacity, which is enough to supply 30,000 homes when the wind blows, is being forecast compared with 1,368Mw the year before. Analysts are forecasting a 93% drop in the installation of new offshore windfarms in 2013 compared with the previous year. As orders for cables, foundations and other equipment are typically made two to three years ahead of the project being completed, the slowdown will start to bite among UK suppliers next year.

There are other extra projects on the drawing board which are supposed to fill this gap. But planning problems, difficulties securing finance and cost overruns on existing projects mean that these plans could be scaled back. Swedish firm Vattenfall said last month that it would not take up the option of expanding its Thanet windfarm – the largest offshore project in the world – blaming problems securing access to the grid.

The availability of bank finance for offshore projects – at least twice as costly as onshore windfarms – has still not returned to pre-credit crunch levels. Now there are only 10-14 banks actively lending, compared with almost 40 before 2008, each lending about half what they were lending before.

Just a few days ago Reuters reported:

The wind energy industry continues to struggle and Vestas Wind is confirming what General Electric is seeing… weak demand. GE went so far as to say the US wind energy market has collapsed. Vestas hasn’t made similar claims, but their actions speak much louder than words.

The company is cutting 3000 jobs and shutting plants due to shrinking power demand, rising component costs and uncertain US policy. While the company posted a smaller than expected loss in 3rd quarter profits, they indicated that the European wind energy market won’t live up to expectations either. Shares of Vestas were down nearly 10 percent Tuesday despite beating analyst earnings estimates and trading very close to the 2008 lows.


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