Another A380 Woe?
His frustration as of late is almost palpable. He has bet the farm on the A380 and has surprisingly, rather than abandon this marginal beast, taken the “in for a penny in for a pound” approach.
STC also said: “Engine manufacturers were moving too quickly to try to meet specifications. When it came to innovation they did little and sat on their hands, they overpromised and what we see now is the result of that.”
I couldn’t agree with him more. The operational shortcomings experienced by the GenX, Trent, Leap and GTF are disgraceful, and in the case of those engines installed on ETOPS certified aircraft, the industry and traveling public have been most fortunate that there have been no dual engine failures or ditchings.
STC also said: “Engine manufacturers were moving too quickly to try to meet specifications. When it came to innovation they did little and sat on their hands, they overpromised and what we see now is the result of that.”
I couldn’t agree with him more. The operational shortcomings experienced by the GenX, Trent, Leap and GTF are disgraceful, and in the case of those engines installed on ETOPS certified aircraft, the industry and traveling public have been most fortunate that there have been no dual engine failures or ditchings.
If Emirates didn't ask for the unachievable, then they wouldn't have suppliers failing - and as to his suggestion that they sit on their hands, that's nonsense. Nobody invests for 36 aircraft.
Suppliers put money in where they get a decent return - and if you buy an engine supporting a tiny fleet, and there's an opportunity to invest on a new engine serving a fleet many times its size, its ridiculous for Emirates to think the supply chain would do anything else than invest in the bigger fleet size market. Unfortunately his comment is symptomatic of the best airline, a great (older) aircraft and an expectation of the having the biggest baseball bat on the field to beat up the supply chain like in the past, but realising there's nobody left on the field to play ball with as everyone has gone elsewhere to play.
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes
on
0 Posts
Taco,
Can you tell us about all the disgraceful shortcomings and your source of this information? Also, maybe you can explain why there haven't been any dual engine failures on ETOPS certified aircraft besides luck.
The operational shortcomings experienced by the GenX, Trent, Leap and GTF are disgraceful, and in the case of those engines installed on ETOPS certified aircraft, the industry and traveling public have been most fortunate that there have been no dual engine failures or ditchings.
Just over a year ago I ferried a 320 NEO back to our maintenance base after it had experienced engine vibration. The maintenance crew that swapped the engine was on board with me. They told me that in the previous 18 months on four NEOs they had swapped 27 engines, so engines lasted around 3 MONTHS before parts needed to be replaced. Our 5th NEO was parked without engines due to lack of spare engines. There is plenty of evidence that they started hanging the engines on wings before they were fully baked.
Join Date: Sep 2011
Location: earth
Posts: 1,098
Likes: 0
Received 0 Likes
on
0 Posts
Oh, i forgot, he calls the shortage 'fake news' doesn't he, but my obscene roster tells the truth ...
STC gets even more trumpeske by the day:
"For Emirates itself, he said the biggest challenge currently is higher fuel prices. “At the moment we got huge problems with the fuel price, which is really destroying value for us, it really hit our bottom line quite hard, we haven’t had a good first half year just because of fuel.”
Same goes for the braggart who bought a Hummer to commute and then blames and lectures the manufacturer about his engineering, but never himself who could have settled for a nice Lexus.
Can you tell us about all the disgraceful shortcomings and your source of this information? Also, maybe you can explain why there haven't been any dual engine failures on ETOPS certified aircraft besides luck.
Taco, why should we have to do the research to back up your accusations? I'd like to see you back up this statement in particular:
I have considerable first hand experience with the GEnx - and your statement is demonstrably false. The GEnx had one of the smoothest EIS of any commercial engine ever. The IFSD rate out of the box was very, very good - much better than the minimum 180 minute ETOPS requirement - and while time on wing was a bit disappointing initially it's rapidly improved and is now doing quite well in that regard. In fact the really only meaningful issue with the GEnx was Ice Crystal Icing (ICI) - something that is still poorly understood (and not covered by the regulations). Further, although ICI caused some temporary thrust losses and engine damage, there were no shutdowns, and a fix was identified and certified. The Trent 1000 on the 787 has had it's issues, but they are mainly related to an unexpected wear out mode that didn't show up until the engine had been in service for years - out of the box the Trent 1000 was quite good. The LEAP has had a reasonably smooth EIS (getting/keeping production up to speed has been a problem but the engine itself has been reasonably trouble free). Only the GTF has had major issues (not exactly a surprise given it's totally new technology - there is a reason why Boeing decided to pass on the first iteration of the GTF).
The operational shortcomings experienced by the GenX, Trent, Leap and GTF are disgraceful, and in the case of those engines installed on ETOPS certified aircraft, the industry and traveling public have been most fortunate that there have been no dual engine failures or ditchings.
I thought geared fans went back to the BAe146/RJ on airliners, as well as various military and bizjet types. And that it's not the new technology that has been the (multiple) issues anyway, but the more standard components.
Join Date: Jun 2018
Location: New York City
Posts: 49
Likes: 0
Received 0 Likes
on
0 Posts
You’re right, it’s not “totally new technology,” I think he just meant it’s new in the sense of the size of this application.
Exactly - there is a wee bit of difference in technology between a 7,000 lb. thrust class GTF and one producing about five times that much thrust. Boeing may have made the decision for the wrong reasons, but I doubt many people working the MAX think they made the wrong decision...
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes
on
0 Posts
Original Posting by Commander Taco:
Turbine D: Buy yourself a subscription to Flight International. Go back into their back issues archives for roughly four years and start reading up until present day. You'll see these engines have/had some very serious issues and yet when initially certified received 180 minutes "out of the box", as the jargon goes.
Turbine D: Buy yourself a subscription to Flight International. Go back into their back issues archives for roughly four years and start reading up until present day. You'll see these engines have/had some very serious issues and yet when initially certified received 180 minutes "out of the box", as the jargon goes.
I have considerable first hand experience with the GEnx - and your statement is demonstrably false. The GEnx had one of the smoothest EIS of any commercial engine ever. The IFSD rate out of the box was very, very good - much better than the minimum 180 minute ETOPS requirement - and while time on wing was a bit disappointing initially it's rapidly improved and is now doing quite well in that regard. In fact the really only meaningful issue with the GEnx was Ice Crystal Icing (ICI) - something that is still poorly understood (and not covered by the regulations). Further, although ICI caused some temporary thrust losses and engine damage, there were no shutdowns, and a fix was identified and certified. The Trent 1000 on the 787 has had it's issues, but they are mainly related to an unexpected wear out mode that didn't show up until the engine had been in service for years - out of the box the Trent 1000 was quite good. The LEAP has had a reasonably smooth EIS (getting/keeping production up to speed has been a problem but the engine itself has been reasonably trouble free). Only the GTF has had major issues (not exactly a surprise given it's totally new technology - there is a reason why Boeing decided to pass on the first iteration of the GTF).
Regulatory bodies have been in the business of certifying turbine engines for civilian use for what, approximately 58 years? It is not acceptable that the Trent and GenX were certified right away for 180 minutes given the unreliability demonstrated by these engines. I mean, one engine that wears out prematurely? After six decades of turbine engine design, construction and certification, excessive engine wear slips by and then is written off as a “whoopsies”? And the other engine that sneezes and coughs if you fly in ice crystals or can pack it in completely if the fan blades ice up?
Turbine D & tdracer: respectfully, you both must be engineers if you can so blithely dismiss these serious engine issues as “temporary thrust losses and engine damage”. What you both are elucidating is called “the normalization of deviance” when you suggest that dual thrust loss is somehow fine, especially so if it’s just temporary.
BTW, 41 years in the pointy end. My post-retirement job makes me privy to incident reports/technical bulletins, etc.
Taco
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes
on
0 Posts
Original Post by Commander Taco
Turbine D & tdracer: respectfully, you both must be engineers if you can so blithely dismiss these serious engine issues as “temporary thrust losses and engine damage”. What you both are elucidating is called “the normalization of deviance” when you suggest that dual thrust loss is somehow fine, especially so if it’s just temporary.
BTW, 41 years in the pointy end. My post-retirement job makes me privy to incident reports/technical bulletins, etc.
Turbine D & tdracer: respectfully, you both must be engineers if you can so blithely dismiss these serious engine issues as “temporary thrust losses and engine damage”. What you both are elucidating is called “the normalization of deviance” when you suggest that dual thrust loss is somehow fine, especially so if it’s just temporary.
BTW, 41 years in the pointy end. My post-retirement job makes me privy to incident reports/technical bulletins, etc.
There was one other incident I recall where ice crystals in the fuel caused a Boeing 777, operated by BA, to land short of the runway because of restrictive fuel flow to the engines when added power was demanded. The fuel/oil heat exchanger was modified to correct the problem on RR engines.
You paint a very dire picture of the engines that power jet aircraft. I would suggest to you that your career at the pointy end wouldn't have lasted 41 years with the picture you paint if it were true...
Last edited by Turbine D; 6th Nov 2018 at 15:00. Reason: added paragraph
To be fair, the FAA AD issued in response to the JAL 787 event did say, rather chillingly:
"We are issuing this AD to prevent susceptibility to heavy fan blade rubs, which could result in engine damage and a possible in-flight non-restartable power loss of one or both engines".
My understanding is that it was simply luck, and not by design, that the aircraft in question hadn't had both engines upgraded to the PIP2 standard, whereas some others in the fleet had.
"We are issuing this AD to prevent susceptibility to heavy fan blade rubs, which could result in engine damage and a possible in-flight non-restartable power loss of one or both engines".
My understanding is that it was simply luck, and not by design, that the aircraft in question hadn't had both engines upgraded to the PIP2 standard, whereas some others in the fleet had.
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes
on
0 Posts
GEnx Icing Problem
Commander Taco,
This is from a 2016 thread on PPRuNe by the same title. So how do you test for something that isn't clearly understood and can't be reproduced like normal certification ice testing is done? Check the rest of the thread for more info...
This is from a 2016 thread on PPRuNe by the same title. So how do you test for something that isn't clearly understood and can't be reproduced like normal certification ice testing is done? Check the rest of the thread for more info...
This very serious generic type incident got buried by PPRuNe in the freighter forum
below is an excellent summary and a hope that it really can be addressed before it gets compounded into an accident.
I really don't see any of the big engines being totally immune from this until a level playing field design and cert standard is available
Boeing, GE Test Upgrades To Counter Engine Icing
Quote:
The July 31 incident, which hit an AirBridge Cargo 747-8F enroute from Moscow to Hong Kong, is the latest encounter of a high flying aircraft with the poorly-understood phenomenon of core engine icing. In this situation engines can surge and suffer power ‘roll-backs’ strike with little or virtually no warning because ice crystal clouds do not show up on weather radar. The problem is unusual because it generally occurs at high altitudes where atmospheric moisture levels are normally very low, and because it impacts the high pressure core of turbofans which were previously thought to be virtually immune from significant icing.
The AirBridge Cargo 747-8F was in darkness at 41,000-ft over China, near Chengdu, when it deviated to avoid a thunderstorm. According to Russian federal air transport authority Rosaviatsia, the aircraft entered an unseen area of icecrystal cloud not shown on the weather radar. Air temperature rose by 20 deg C to minus 34 deg C for a period of 86 seconds, and the crew switched the engine ice protection system from automatic to manual for around 10 minutes.
Around 22 minutes after flying through the warmer sector the aircraft’s No.2 (inboard left) engine surged and automatically restarted. The No.1 engine then experienced a speed reduction of 70% of N1. After landing at Hong Kong inspections revealed damage to the high-pressure compressor blades of the No.1 and 2 engines as well as the No.4.
Boeing says the flight test effort is focused on “verifying operational elements” of a change to the engine control software. The testing included monitoring the development of ice crystals on the GEnx-2Bs powering RC021, one of the company’s test airframes that has recently been used to evaluate fuel system upgrades and other performance improvements. The fully-instrumented aircraft was originally designated for 747-8I launch customer Lufthansa, but was retained as a test asset after the German carrier opted not to take the modified airframe.
The software changes to the GEnx-2B full authority digital engine control unit are designed to help the engine itself detect the presence of ice crystals when the aircraft is flying through a convective weather system. If detected, the new algorithms will schedule variable bleed valves to open and eject ice crystals that may have built up in the area aft of the fan, or in the flowpath to the core. The modification to the GEnx control logic leverages similar changes made to improve the ability of the CF6 to operate in similar icing conditions.
The ABC event is the latest in a growing number of engine icing incidents which have triggered recent changes in international certification requirements. Unlike traditional engine icing, in which supercooled liquid droplets freeze on impact with exposed outer parts of the engine as the aircraft flies through clouds, engine core ice accretion involves a complex process in which ice particles stick to a warm metal surface. These act as a heat sink until the metal surface temperature drops below freezing, thereby forming a location for ice and water (mixed phase) accretion. The accumulated ice can either block flow into the core, or shed into the downstream compressor stages and combustor, causing a surge, roll-back or other malfunction.
Until relatively recently is has been assumed ice particles would bounce off structures and pass harmlessly through bypass ducts, or melt inside the engine. Now there is evidence that there is an environment where there is a combination of water, ice and airflow which is susceptible to accreting ice. Like many of the other known core icing events, the ABC 747-8 incident occurred near convective clouds.
When incidents were first reported, investigators initially assumed supercooled liquid water, hail or rain was responsible because it had been lifted to high altitudes by updrafts. Most events were recorded above 22,000-ft, which is considered the upper limit for clouds containing supercooled liquid water. However, pilots reported that even though they were in cloud at the time, there was no evidence of the usual indications of trouble, including significant icing on the airframe or any other remarkable aspect to the weather.
below is an excellent summary and a hope that it really can be addressed before it gets compounded into an accident.
I really don't see any of the big engines being totally immune from this until a level playing field design and cert standard is available
Boeing, GE Test Upgrades To Counter Engine Icing
Quote:
The July 31 incident, which hit an AirBridge Cargo 747-8F enroute from Moscow to Hong Kong, is the latest encounter of a high flying aircraft with the poorly-understood phenomenon of core engine icing. In this situation engines can surge and suffer power ‘roll-backs’ strike with little or virtually no warning because ice crystal clouds do not show up on weather radar. The problem is unusual because it generally occurs at high altitudes where atmospheric moisture levels are normally very low, and because it impacts the high pressure core of turbofans which were previously thought to be virtually immune from significant icing.
The AirBridge Cargo 747-8F was in darkness at 41,000-ft over China, near Chengdu, when it deviated to avoid a thunderstorm. According to Russian federal air transport authority Rosaviatsia, the aircraft entered an unseen area of icecrystal cloud not shown on the weather radar. Air temperature rose by 20 deg C to minus 34 deg C for a period of 86 seconds, and the crew switched the engine ice protection system from automatic to manual for around 10 minutes.
Around 22 minutes after flying through the warmer sector the aircraft’s No.2 (inboard left) engine surged and automatically restarted. The No.1 engine then experienced a speed reduction of 70% of N1. After landing at Hong Kong inspections revealed damage to the high-pressure compressor blades of the No.1 and 2 engines as well as the No.4.
Boeing says the flight test effort is focused on “verifying operational elements” of a change to the engine control software. The testing included monitoring the development of ice crystals on the GEnx-2Bs powering RC021, one of the company’s test airframes that has recently been used to evaluate fuel system upgrades and other performance improvements. The fully-instrumented aircraft was originally designated for 747-8I launch customer Lufthansa, but was retained as a test asset after the German carrier opted not to take the modified airframe.
The software changes to the GEnx-2B full authority digital engine control unit are designed to help the engine itself detect the presence of ice crystals when the aircraft is flying through a convective weather system. If detected, the new algorithms will schedule variable bleed valves to open and eject ice crystals that may have built up in the area aft of the fan, or in the flowpath to the core. The modification to the GEnx control logic leverages similar changes made to improve the ability of the CF6 to operate in similar icing conditions.
The ABC event is the latest in a growing number of engine icing incidents which have triggered recent changes in international certification requirements. Unlike traditional engine icing, in which supercooled liquid droplets freeze on impact with exposed outer parts of the engine as the aircraft flies through clouds, engine core ice accretion involves a complex process in which ice particles stick to a warm metal surface. These act as a heat sink until the metal surface temperature drops below freezing, thereby forming a location for ice and water (mixed phase) accretion. The accumulated ice can either block flow into the core, or shed into the downstream compressor stages and combustor, causing a surge, roll-back or other malfunction.
Until relatively recently is has been assumed ice particles would bounce off structures and pass harmlessly through bypass ducts, or melt inside the engine. Now there is evidence that there is an environment where there is a combination of water, ice and airflow which is susceptible to accreting ice. Like many of the other known core icing events, the ABC 747-8 incident occurred near convective clouds.
When incidents were first reported, investigators initially assumed supercooled liquid water, hail or rain was responsible because it had been lifted to high altitudes by updrafts. Most events were recorded above 22,000-ft, which is considered the upper limit for clouds containing supercooled liquid water. However, pilots reported that even though they were in cloud at the time, there was no evidence of the usual indications of trouble, including significant icing on the airframe or any other remarkable aspect to the weather.
I think they changed something on the bypass doors back then plus maybe modified the engine software IIRC and it ended.
I don't think either of us engineers ever suggested dual thrust loss is somehow fine
Further, although ICI caused some temporary thrust losses and engine damage, there were no shutdowns,
Lots of hedging in that statement but hey, ok! There were no engine shutdowns, it's all good.
The only dual engine thrust loss that I recall happened on a Boeing 767 out of LA when the pilots on the pointy end accidentally shut off the fuel flow to the engines.
So how do you test for something that isn't clearly understood and can't be reproduced like normal certification ice testing is done?
"Social normalization of deviance means that people within the organization become so much accustomed to a deviant behavior that they don't consider it as deviant, despite the fact that they far exceed their own rules for the elementary safety"
The real shame of it though, is that the industry has to keep relearning lessons already learned. Below is a short summary (not written by me) of an incident from author Ernest K. Gann's flying career as detailed in his book: "The High And The Mighty".
Another interesting story to prove this point also almost cost Ernie his life. He was flying a DC-4 after the war for an airline. Ernie considered the DC-4 a very safe and reliable aircraft.
After takeoff on a flight from San Francisco to Honolulu, as the aircraft ascended above 3,000 feet, all four big radials began acting up, with at least one of the engines quitting entirely. Had the crew not taken immediate action to adjust throttles, mixtures, and prop pitch, all four engines likely would have stopped turning.
The mystery of the reluctant engines was solved after they nursed the aircraft back to San Francisco. Prior to the flight, unknown to the flight crew, the spark plugs had been replaced with a “new and improved” version for this model of Pratt & Whitney engines. The new engine/spark plug combination had never been field tested, but the Pratt & Whitney engineers had assured their higher-ups that their slide rules confirmed the plugs would work. The plugs did not; at least not above 3,000 feet. Had Ernie viewed the engine log books or made some inquiries about the nature of the maintenance performed on the aircraft, he may have been in a better position to evaluate the real flight risk on the ramp rather than being forced to deal with it in-flight.
After takeoff on a flight from San Francisco to Honolulu, as the aircraft ascended above 3,000 feet, all four big radials began acting up, with at least one of the engines quitting entirely. Had the crew not taken immediate action to adjust throttles, mixtures, and prop pitch, all four engines likely would have stopped turning.
The mystery of the reluctant engines was solved after they nursed the aircraft back to San Francisco. Prior to the flight, unknown to the flight crew, the spark plugs had been replaced with a “new and improved” version for this model of Pratt & Whitney engines. The new engine/spark plug combination had never been field tested, but the Pratt & Whitney engineers had assured their higher-ups that their slide rules confirmed the plugs would work. The plugs did not; at least not above 3,000 feet. Had Ernie viewed the engine log books or made some inquiries about the nature of the maintenance performed on the aircraft, he may have been in a better position to evaluate the real flight risk on the ramp rather than being forced to deal with it in-flight.
Join Date: Dec 2010
Location: Middle America
Age: 84
Posts: 1,167
Likes: 0
Received 0 Likes
on
0 Posts
Commander Taco,
I hate to tell you, but your operative words in your quote above weren't just hedgy, they just weren't true. I know because a co-worker of mine was on that aircraft and said the silence was eerie. The pilot who operated the switches did so without looking, the memory of his flying 727s and switch positions was etched in his mind. The CF6-80 had the quickest start time compared to the JT9s or RB211s, the RBs being the slowest. The Aircraft was within 300 feet of the ocean when the first CF6-80 started and began to generate enough power to begin a slow climb out. The pilots flew the aircraft on to Cincinnati, never explaining to the frightened passengers what happened.
It was a Pratt JT9D powered B767-200 (not a particularly fine engine BTW.
Excerpt from the July 3,1987 New York Times
The latest Government order called for installing a guard between the two fuel levers to ''inhibit simultaneous activation'' of both devices.
It said that ''normal crew training emphasizes actuating only one engine-control switch at a time,'' adding, however, that the location of the devices on the Boeing 767 made it possible to operate switches for both engines simultaneously.
Planes like the Boeing 767 can readily maintain safe flight with only one engine operating.
The order imposed a 10-day deadline for making the change on all 77 of the Boeing 767's in use in the United States as well as on 30 domestic Boeing 757's using Rolls-Royce engines. The 767 involved in the incident Tuesday was powered by General Electric engines.
The latest Government order called for installing a guard between the two fuel levers to ''inhibit simultaneous activation'' of both devices.
It said that ''normal crew training emphasizes actuating only one engine-control switch at a time,'' adding, however, that the location of the devices on the Boeing 767 made it possible to operate switches for both engines simultaneously.
Planes like the Boeing 767 can readily maintain safe flight with only one engine operating.
The order imposed a 10-day deadline for making the change on all 77 of the Boeing 767's in use in the United States as well as on 30 domestic Boeing 757's using Rolls-Royce engines. The 767 involved in the incident Tuesday was powered by General Electric engines.
Join Date: Jun 2001
Location: Rockytop, Tennessee, USA
Posts: 5,898
Likes: 0
Received 1 Like
on
1 Post
Don't know if it's another A380 technical problem but BA269 is doing an air turnback to LHR right now after squawking 7700 going feet wet off the coast of Scotland.
Join Date: Jun 2018
Location: New York City
Posts: 49
Likes: 0
Received 0 Likes
on
0 Posts
"The flight is returning to Heathrow due to a minor technical issue.
"Safety is always our very highest priority and our highly trained flight crew will always err on the side of caution."
I wonder what the spokesman's definition of "minor" is.
