South Korea Jeju air plane crash
- Thread starter bingham67
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Looks like we can expect some photos of Korean airport officials with bowed heads (or is it only a Japanese thing?). Been reported in Korean media apparently that this was known about as a safety risk and that there was a recommendation to remove it.
I'll be amazed if there wasn't a recommendation at some point. These things are always tricky, it doesn't matter how many safety features you implement, an auditor needs to earn his bread and will find stuff. Not denying that this isn't a valid recommendation ofc, but it might well be 20 years old and mentioned as a P3 in a H&S audit.
London city appears to have this structure at one end (the other end has a runoff that ends in water). There's a definite curve to this wall, I wonder if it's designed to take at least some sort of impact?
looks faimilar off gta v
It's not odd at all, if this type of incident happened there it would be an even worse disaster. City airport is still rated for decent sized jets. I wouldnt fancy being there with for example an E190 coming off the end of the runway at 150mph.
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In a very surprising update it appears that the flight data and cockpit voice recoreders were not recording for the final 4 minutes of the flight, and that would be from the time of the possible bird strike. Very strange indeed, and may suggest a complete electrical failure on board, which I think would tie in with the lack of data from flight radar.
Indeed, in fact the very aircraft in this incident (a 737-800) would not be permitted to land at London City airport, it requires a min length of like 2000 meters or so for landing. The largest aircraft they'll let land is like an A220 etc.. which requires a runway at least 1350 meters for landing.
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Pretty scary that then a complete electrical failure, surely that would be picked up in maintenance or is it just something that can happen?
They may have shut down the wrong engine in a panic also?
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Aircraft have CB’s, remote CB’s, fuses, generators, batteries, cross-ties, transformers, rectifiers, static inverters - every sort of electrical component you can imagine to ensure they always have power of some sort.
Without the specific diagrams to see how the -800 architecture works and where the FDR/CVR get their power from, it’s very odd that they (and presumably the ADS transmitter) have completely lost power like that. Many questions are going to go unanswered I suspect.
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Apparently it’s powered only by the AC systems, and predates the FAA requirements to have a battery backup supply. If both engines were not producing electrics, and they didn’t start the APU, then you have no recording it would seem.
Was an interesting video, someone mentioned and I can see from https://www.737ng.co.uk/B_NG-Fire_Protection.pdf
Pulling the engine fire switch closes fuel valves, it trips the generator relays and breakers, closes hydraulic valves, disables thrust reverser for the related engine etc.
It also says the switches are unlocked if engine fire or engine overheat warnings are detected.
I don’t know if the videos of the crash show the left engine well enough but I’m sure I read that the thrust reverses were only deployed on the right engine?
I’m sure the analysis of the cvr will hear any fire warning bells before they stopped working. I wonder if they had multiple bird strikes where one of the engines detected an overheat, fire, I,e. The left one first, so they deployed the fire extinguisher, then maybe the generator on the right tripped or failed on them leaving them with no ac so the pilots felt they had to try to land asap instead of having time to bring up the apu etc?
Pulling the engine fire switch closes fuel valves, it trips the generator relays and breakers, closes hydraulic valves, disables thrust reverser for the related engine etc.
It also says the switches are unlocked if engine fire or engine overheat warnings are detected.
I don’t know if the videos of the crash show the left engine well enough but I’m sure I read that the thrust reverses were only deployed on the right engine?
I’m sure the analysis of the cvr will hear any fire warning bells before they stopped working. I wonder if they had multiple bird strikes where one of the engines detected an overheat, fire, I,e. The left one first, so they deployed the fire extinguisher, then maybe the generator on the right tripped or failed on them leaving them with no ac so the pilots felt they had to try to land asap instead of having time to bring up the apu etc?
In the event of a failure of all electrical generators (in itself, highly unlikely) the aircraft should still have enough battery power to fly for 45 mins. (That 45 min figure can vary depending on the exact requirements of the local CAA certification rules). Nonetheless, a complete electrical failure of the electrical system is so incredibly unlikely that I suspect something else is going on here.
If I'm not mistaken, London city airport requires a 4.5 degree glideslope (typically this is 3 degrees) to avoid hitting the taller buildings in London. This is what limits the types of aircraft that can land there. Certainly a B737 can land on a much shorter runway than 2000m.
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Whilst true, that doesn’t seem to be what’s doing on here. Current information would suggest a bird strike in the right engine which probably caused enough damage to take the generator offline, followed by a shutdown of the wrong engine which would take the other AC system offline.
If they didn’t choose to start up the APU and its own generator, then they’d be flying around on battery power only. Whilst there is a static inverter to make AC from this DC, the systems it powers would be emergency ones only, and in this case not the FDR apparently.
It wouldn’t have been a case of the cockpit being dark with no screens or readouts etc
Certainly shutting down the wrong engine is going to cause a whole world of problems and if that's what happened it goes some way to explaining how this has unfolded. In the ensuing panic its easy to see how the APU generator could get overlooked.
I must admit I've been flying the B737 for almost 20 years and having flown most variants, I've always assumed that in the event of the loss of all electrical power generation, the FDR would be be powered off the main or aux battery (but never really thought about it a great deal) but having just checked our company manuals it would appear there is something called RIPS (Recorder Independent Power Supply) for the FDR and its an optional extra.
That being said - the Boeing tech manuals from a pilots perspective are quite light on details and its not entirely clear to me that the FDR isn't powered off one of the standby busses. It doesn't clearly state whether it is or isn't but you can kind of infer that it is from the electrical system diagrams. That being said I could be wrong and it not being the case does explain whats happened in this accident. As always however, it's probably a good idea to be very cautious about drawing any conclusions this early on.
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My background is maintenance and I’ve never worked 737 so I’m getting my information third hand. What I have learnt over the years is how different every aircraft is in terms of architecture and operation: automatic bus ties, decoupling of the buses, what works with electrics as backup and what systems are actually fed in various configurations.
I’ve also definitely never shut down all engines without turning on the APU generator first during a ground run and watched the whole 1970’s cockpit throw a wobbly…