So you know about the microprocessors falling off the boards on GE engine FADECs the icing problem that meant in some cases you have to run engines from different years on either side of the aircraft? Oh and the contaminated compressor rotor spools from last year.
Given the number of uncontained failures recorded for GE engines I cannot personally see how you can say that? The Trent 900 was designed not to fail in that way either until it did so who is to say there is not a failure mode on the GEnx that has not been imagined (and hopefully will not occur)? Answer you can't as no one can, they can just say they have allowed for all the failures they can conceive of. So my question is still valid. And as you said the systems are complex. Even the subsystems are complex. So there can be failures no one will have imagined until they happen.
Now here is a question for the human factors guys. Airlines that buy the full telemetry pack will not only have their own engineers seeing things in near real time, but the engine manufacturers will as well (and can modify the FADEC config remotely, which is not at all scary). So in the case of something going wrong it's not unlike NASA mission control with several to many people poring over the data and hopefully with a feedback path to the team in the cockpit. In the case of a multi-system failure would it be right if the people on the ground had access to more information than the pilot with whom the ultimate responsibility for the souls on board lies (6L6 correct me if I am wrong on this last point).
Reason I ask is that, if you try and keep the cockpit data delivery at a rate that it is considered the crew can handle then someone else knows more than them, which to me outside the whole industry seems wrong.
I didn't say GE engines don't fail... they just don't fail explosively like the RR engines do sometimes.... this is because GE uses composite materials instead of metals in the turbines. BTW, mixing components from different years is not an issue.
By cockpit delivery data rate... do you mean how data is delivered (presented) to the crew or the rate at which data is transferred across the data busses and other connections?
Data supplied to the crew tends to run through a debouncing filter first. Meaning that fast ON/OFF or data losses are not presented to the crew immediately, nor are they -typically- stored in a very deep queue for subsequent browsing by the crew. Normally, there is some specific data storage/analysis equipment in the aircraft to store the data and then that is download and viewed with test equipment. (BTW, I did work at installing one of them for the C17... it became a standard issue for Commercial Airplanes after we validated the system).
Also, data is processed at different levels... per DO178B/C. There's five levels, A, B, C, D and E. A means catastrophic.... so A and B data is usually presented to the crew immediately. C, D and E are presented based upon some manufacturer design option.
The idea is not to overwhelm the crew with data, but this is pretty much left to the avionics designer. Boeing believes the pilot flies the airplane, hence they give the crew a lot more control.... Airbus believes the computer knows best, so they are half way to an unmanned aircraft.
Remote control of engines.. yes. It is an interesting thing. The "recovery path" you discuss up is different from NASA though.
I was told that GE barely breaks even on the sale of engines, they make money on the operation and maintenance. These things are rather complicated and are monitored real time. Remember that Malaysian airliner that got lost? The last signals they got from it were from its engines. Anyhow, you would not download new firmware to a FADEC during operation... that would require a reboot and shutting down the engine if in operation. Most likely, the plane would land somewhere, ETOPS or not. You might have to shut down the engine in question and then you don't know if it will re-start.
This is actually VERY different from a spacecraft, and a satellite, where updating the firmware, specially the bootable firmware, is extremely rare. There is no way to "land" the vessel. The simple fact of rebooting a spacecraft carries tons of risk.... imagine the risk of changing the boot image! You run the very clear risk of losing the spacecraft and the mission... that's why I brought up the instance of one of the Mars landers. It was one of the very few instances where they actually did change the boot image, flipped the switch, got on their knees and prayed for five minutes or so.
Even stuff like telco approaches that.... sending crews to the vault can be a costly PITA. So, rebooting or updating the image (always done remotely) is not something you want to do. If it fails, then you have an expensive outage.
"I didn't say GE engines don't fail... they just don't fail explosively like the RR engines do sometimes."
https://www.seattletimes.com/busine...on-boeing-767-poses-puzzle-for-investigators/
https://www.seattletimes.com/busine...on-boeing-767-poses-puzzle-for-investigators/
GE engines too experience uncontained failures.
Composite material in turbine (rotating and static parts): NO. Only metals (high alloys for rotating parts)
See here. Pages 8 (bottom) to 23 (included) and pages 39 to 45
https://www.ntsb.gov/investigations/AccidentReports/Reports/aar1801.pdf
Also here for dymamics analysis and data
https://www.tc.faa.gov/its/worldpac/techrpt/ar99-11.pdf
George
Well, first of all, those are 767s, which are old and have old engines. Some one else point this out.
I mistyped.... it not composites in the metal blades but different types of metal alloys that fail differently. I saw a presentation about FADECS and engines, but I forget the details... we were discussing engine failure modes. I recall the 380 failure was an example.
Tony
Metallurgy of high alloy steels is quite involving. Better leave it there.
FADEC and -in passing- engine design presentation, may drive you to form wrong impression.
E.g. you may have been given the impression that high alloys are developed ‘in house’. Or that a high alloy has a life cycle as short as ten years.
RR has used the Inconel 720 while GE has used Inconel 718 for their HPT disks.
I posted the link and guided for the pages only for to point to the details where the devil resides.
But you still stick to labels.
George
Metallurgy of high alloy steels is quite involving. Better leave it there.
FADEC and -in passing- engine design presentation, may drive you to form wrong impression.
E.g. you may have been given the impression that high alloys are developed ‘in house’. Or that a high alloy has a life cycle as short as ten years.
RR has used the Inconel 720 while GE has used Inconel 718 for their HPT disks.
I posted the link and guided for the pages only for to point to the details where the devil resides.
But you still stick to labels.
George
Let me put it this way... the FADECs are designed to reflect the engine and it's behavior. Including likely failures...
They also reflect the aircraft...
767 are old aircraft with old engines. It's hard to compare old with new.
Similarly, people picking on Boeing over old aircraft and bad maintenance over which they have little control.
Remember how the DC-10 was killed off when that one crashed on take off at O'Hare? It turns out the maintenance crew used a forklift to install the engine even as Douglas specifically had instructions NOT to do that. So, the airplane was killed off because the media is lazy and ignorant.
It didn't help that before that, there was a serious incident and a tragic crash due to to a deliberate and flawed design decision by the manufacturer.
MD was well aware of the rear cargo door issues and chose to overlook them in the design phase. After after a near-crash by an American Airlines DC-10 when the rear cargo door almost came off, it lobbied the FAA to issue a non urgent 'service bulletin' instead of a mandatory Airworthiness Directive which would have grounded the DC-10 fleet. As a result of that, hundreds of people lost their lives when the rear cargo door blew off a Turkish Airlines DC-10.
Geoff
Aaah, the good old days.... flying out of Orange Cty ( just after it became John Wayne ).... in AirCal.
https://en.wikipedia.org/wiki/Air_C...6-200_N141AC_Aircal_ORC_16.10.86_edited-2.jpg
Eventualy PSA started serving it but they flew low wing 727 and 737.
Indeed. East-West merged with Ansett in 1993. We’ve probably been on the same planes.
I recall one time, one of the engines was quite unbalanced throughout the flight. Nobody seemed to be too concerned.
I think that might have been an issue with propeller synch.
Particularly on a piston engined plane like a DC-3, on which I've travelled many times, you do notice when the props aren't perfectly synchronised but it's no cause for alarm. I think...
All the DC-3s/C47s on which I've flown have had Pratt and Whitney engines, but Ansett used the reportedly less smooth running Wright Cyclones. Only two DC-3s used Rolls Royce engines, the same as the F27: Rolls Royce Dart; BEA ran them as an experiment in the early 50s. However, passengers wouldn't have seen that reassuring RR logo as the nacelles protruded too far forward.
Yes it's old and simple, but the DC-3/C-47 is one of the best, most reliable, strongest and safest aircraft ever made. There were some design issues which, sadly, caused fatal crashes but they were quickly identified and fixed.
Wing strength was tested by driving a steam-roller over the wing during testing; fuselage strength was tested many times, as when a C-47 survived a collision with a Japanese Zero fighter. Load capacity was tested many times, with one flight carrying over 70 passengers (many of them children), or carrying a load of pierced steel planking when it was supposed to be aluminium.
The body of a DC-3 would just about fit inside the rear (centre) engine fairing of a DC-10.
Geoff
Particularly on a piston engined plane like a DC-3, on which I've travelled many times, you do notice when the props aren't perfectly synchronised but it's no cause for alarm. I think...
All the DC-3s/C47s on which I've flown have had Pratt and Whitney engines, but Ansett used the reportedly less smooth running Wright Cyclones. Only two DC-3s used Rolls Royce engines, the same as the F27: Rolls Royce Dart; BEA ran them as an experiment in the early 50s. However, passengers wouldn't have seen that reassuring RR logo as the nacelles protruded too far forward.
Yes it's old and simple, but the DC-3/C-47 is one of the best, most reliable, strongest and safest aircraft ever made. There were some design issues which, sadly, caused fatal crashes but they were quickly identified and fixed.
Wing strength was tested by driving a steam-roller over the wing during testing; fuselage strength was tested many times, as when a C-47 survived a collision with a Japanese Zero fighter. Load capacity was tested many times, with one flight carrying over 70 passengers (many of them children), or carrying a load of pierced steel planking when it was supposed to be aluminium.
The body of a DC-3 would just about fit inside the rear (centre) engine fairing of a DC-10.
Geoff
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