|
FAA URGENT 787 GE ENGINE ISSUE
FAA Orders ?Urgent? 787 Repair After Engine Fails at 20,000 Feet - Bloomberg
Airlines flying Boeing Co.’s 787 Dreamliner jets with the latest General Electric Co. engines were ordered to repair them, or swap out at least one with an older model, in an urgent safety directive issued after an in-flight failure. A GEnx-1B PIP2, part of a family of engines plagued by issues related to icing, suffered “substantial damage” in the Jan. 29 incident, when ice on the fan blades broke loose, the U.S. Federal Aviation Administration said in an order published Friday in the Federal Register. “The potential for common cause failure of both engines in flight is an urgent safety issue,” the FAA said in its order. The GEnx, a high-efficiency engine developed for wide-body aircraft, has faced earlier issues with icing. In 2013, the FAA ordered airlines to avoid flying 787 and 747-8 planes equipped with the GE engines near thunderstorms in high-altitude cruise flight. Even in those sub-freezing temperatures, moisture from the storms could enter the engines and form dangerous ice, the FAA said. |
I can't decide which is more disturbing.
A modern engine design not being able to cope with ice, or the commercial pressures driving pilots to routinely fly through areas of known thunderstorm activity. |
A modern engine design not being able to cope with ice, or the commercial pressures driving pilots to routinely fly through areas of known thunderstorm activity. any 787 pilots care to comment? |
Iomapaseo
The Air Directive orders airlines to avoid flying near thunderstorms in high-altitude cruise flight, which rather suggests that this was/is a routine activity. Lines 10 and 11 of the originally posted extract. Just my interpretation based on two crashes that could be directly linked to airliners flying into thunderstorms in the ITCZ, neither of which were 787s or 747-8s though. |
The specific issue in question has nothing to do with high altitude Ice Crystal Icing (which the GEnx has also had issues with).
Rather, this particular issue is related to the more conventional icing threat (i.e. super cooled droplets) that forms ice on the fan blades at low power. Based on what is currently known, it only applies to one 'version' of the GEnx-1B engine. No known impact on the GEnx-2B (747-8) or the earlier versions of the -1B on the 787. |
A bit more on the FAA and the problem on GE Engines
FAA orders urgent fix to engines that could shut down on Boeing 787s | The Seattle Times The FAA directive, first reported Friday by The Wall Street Journal, states that the problem arises only in the latest upgraded model of the GEnx engine powering the Dreamliner, the GEnx-1B PIP2. That upgrade, which was certified by the FAA and entered service in 2013, improved the fuel burn incrementally, in part by reducing the tiny gap between the tips of the engine’s large fan blades and the fan case. In the January incident, ice had built up on the fan blades before the trouble occurred at an altitude of 20,000 feet as the plane descended. When the ice abruptly shed, it caused the blades to move slightly forward and because of the contour of the fan case, this was enough to make the blade tips rub against the case. The resultant heavy vibrations did so much damage that the engine shut down and could not be restarted. Luckily, the GEnx engine on the other wing of the JAL Dreamliner was older and not the specific upgraded PIP2 design. The FAA directive says that second engine incurred only “minor damage during the icing event and continued to operate normally.” Suggested that two engines be chosen from the then 3 major manufacturers- and that a common interface/mounting be designed so it would be a near plug and play issue. As a senior official later said about him -" We never had a problem diagramming his sentences " And so it goes . . . |
According to an AFP (news agency) report today:
GE recommended the repairs last month, the FAA statement Friday said, and Boeing and GE have been working on the issue for months, with more than 40 Dreamliner engines fixed so far, reports say. The repairs -- involving grinding down engine casings -- can be done without removing the engines from planes. The FAA order also requires that pilots be alerted to new operating procedures for coping with possible icing problems at low altitude. |
Similar to the old "centre line closure" problem that we had with the Sapphire although now at the front as opposed to in the compressor.
|
Avoiding weather whatever the 'new engine' issue...per se
100 nm minimum avoidance around ITCZ -type weather has held me well over the last 40 yrs.
New engines are just being tested in-service. That will always be the case now. Just avoid the weather.....what trainer ever told you to leave less than 100nm from severe weather? (in commercial pax a/c?). WTF? |
100 nm minimum avoidance around ITCZ -type weather has held me well over the last 40 yrs. |
Originally Posted by tdracer
(Post 9353494)
The specific issue in question has nothing to do with high altitude Ice Crystal Icing (which the GEnx has also had issues with).
Rather, this particular issue is related to the more conventional icing threat (i.e. super cooled droplets) that forms ice on the fan blades at low power. Based on what is currently known, it only applies to one 'version' of the GEnx-1B engine. No known impact on the GEnx-2B (747-8) or the earlier versions of the -1B on the 787. |
A modern engine design not being able to cope with ice, |
Originally Posted by Bond'll Do
(Post 9354261)
100 nm minimum avoidance around ITCZ -type weather has held me well over the last 40 yrs.
New engines are just being tested in-service. That will always be the case now. Just avoid the weather.....what trainer ever told you to leave less than 100nm from severe weather? (in commercial pax a/c?). WTF? |
A modern engine design not being able to cope with ice, This is really a silly comment, ice has always been and will always remain a permanent challenge in aviation, regardless of how state of the art equipment is. Sometimes subtle changes to engine (pitot tubes, etc, etc.) design can introduce unwanted icing side effects, often it is impossible to predict it just based on theoretical modelling and ground or in-flight testing only covers most nominal scenarios. After all we do have regulations, that if met, will provide a significant measure of protection. It would appear that this latest problem had to add a crutch fix to finally meet the desired level of safety. If the problem was too much ice, not anticipated in the development and certification, then all models of all engines would have to address the issue at the same time since they all fly at these altitudes 0-20000 ft |
It isn't "too much ice", its is way more subtle then that, it is ice taking advantage of insufficient gaps in the modified engine to start to form.. and what was the reason for the engine modification - improved fuel economy so clearly we have trade-off here between engine fuel efficiency and its resistance to ice. We will have problems like that in the foreseeable future unless all aircraft engine development ceases.
|
What version is fitted to the 787-9? |
Originally Posted by Sqwak7700
(Post 9354312)
Wtf? 100 nm? Yeah, no. Never heard of that one. Never in over 20 years flying tubes have I heard anyone diverting 100nm around weather.
Weather avoidance is something that fascinates me, partly because turbulence turns me from a lover of flight to borderline panic attacks, and partly from a lifelong interest in meteorology. And I seem to read so many different mentalities regarding it. Personally I'd prefer the pilot stayed as far away as possible because any turbulence does cause a lot of fear at the back, and I feel if you're transporting passengers you shouldn't enter areas you're not comfortable with. Sorry if this isba little off topic, but I'd be interested to hear your general strategies? And how much are you considering the commercial side i.e. do you fly in areas you'd rather not if the deviation would be 'too far'? And what is too far? Personally I'm inclined to think paying passengers have a right to think the pilot should be free to take all avoidance he deems necessary. Do you feel some colleagues are 'too brave'? I also occasionally read here about poor radar technique being common, but I tell myself it can't be that bad or we'd be seeing a lot of incidents in SE Asia with the number of flights dodging around the monsters down there! |
Wasn't there something similar with the BAE 146 back in the 1990s ?
|
Originally Posted by G0ULI
(Post 9353434)
I can't decide which is more disturbing.
A modern engine design not being able to cope with ice, or the commercial pressures driving pilots to routinely fly through areas of known thunderstorm activity. |
I don't work the 787, so I'm not as intimately familiar as I am with the 747, but the GEnx-1B "PIP 2" certified over 2 years ago. So I suspect most if not all GE 787's delivered in the last 2 years were delivered with PIP 2 engines. However GEnx-1B engines can be freely interchanged so what a 787 was delivered with and what it's flying with today may not be the same. I only ask because very recently I saw a brand new 787-9 with this exact problem. Not something i had seen on previous older -8 models. |
| All times are GMT. The time now is 02:38. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.