6 ms·

Aside from this specific issue, all of aviation works like this. E.g. the reason the 747 was decommissioned from passenger flight in the US when it was is beca

by avar 8y ago

Aside from this specific issue, all of aviation works like this. E.g. the reason the 747 was decommissioned from passenger flight in the US when it was is because they flew it right up to the day that the FAA mandated that they couldn't fly it anymore. The reason was that they didn't have then-mandatory fuel tank inerting. For something like a decade there were a bunch of planes in the air carrying people that were known to be more likely to explode than some other planes. Regulatory safety is always a messy combination of new requirement and timed phase-out of old systems. Same with cars, you can buy a used car today and even use it as a taxi to ferry passengers without it having safety features that would make it illegal to sell as a newly manufactured vehicle.

rootusrootus 8y ago
Do you mean a specific variant 747? Because 747s are still definitely flying passengers in the U.S. They are still making new ones.
- kenneth 8y ago
  747s are not flying any passengers in the US. They are flying passengers to the US. No US carrier still operates the queen of the skies, though that's mostly due to fuel efficiency. Some US carriers had the 747-400 until a couple years ago when United ditched their last one. I loved flying that bird! A few foreign carriers (Korean, Lufthansa) have the much newer 747-8i, which is a lovely plane but hasn't done well commercially due to those same fuel efficiency concerns.
  - rwc 8y ago
    But parent alleges that the 747 is outside of certification requirements, which is demonstrably false.
    - inferiorhuman 8y ago
      Neither United nor Delta retrofitted a fuel tank interting system, that's why they retired their 747s earlier than expected. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%20120-98A.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/... Paragraph 2-8 indicates the dates compliance became mandatory (Dec 26, 2017 with a potential one year extension). There are 747-400s flying in the United States, however they've all had interting systems retrofitted, are foreign registered, or both.
rwc 8y ago
"E.g. the reason the 747 was decommissioned from passenger flight in the US when it was is because they flew it right up to the day that the FAA mandated that they couldn't fly it anymore." I'm sorry, what? Do you have a source?
- avar 8y ago
  In 1996 TWA 800, a 747 flight, exploded[1]. The cause was lack of fuel tank inerting. The FAA subsequently published a rule in 2007[2] saying that by December 26th, 2017 all passenger airliners needed to have an inerting system by manufacture or retrofitting. UA and Delta[3][4] flew such variants of the 747 to within a month of the FAA deadline. The final flight was on November 7, 2017. You can still fly the 747 into or within the US (as e.g. BA does), you just need to have a newer or retrofitted 747. The rule also doesn't apply to cargo planes. Sorry about the "[747] flight[s] in the US" ambiguity. I was referring to the domestic fleet at the time. Also it wasn't literally "right up to the day" of the rule going into effect, but in the grand scheme of things that's accurate enough. The phase-out was planned to coincide with that rule going into effect, among other reasons. The point being that airlines can and will fly airframes that in one way or another would be illegal to manufacture today for safety reasons, or which will be grounded by the regulator tomorrow unless an expensive retrofitting is carried out. I think that's fine, but apparently the fact that airlines are allowed to fly planes with fixable flaws that have "already killed people" just to save some money is surprising to some. It's all a cost/benefit trade-off, and is considered normal by regulators. There's some more details in this HN comment chain at the time in 2017 that I contributed to[5]. Edit: Some weird HN glitch or mod action seems to have happened. My comment upthread is now a top-level comment, but initially I'd replied to the "already killed people" top-level comment by jfk13[6], and that's definitely how it was rendered for a while. 1. https://en.wikipedia.org/wiki/TWA_Flight_800 https://en.wikipedia.org/wiki/TWA_Flight_800 2. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%20120-98A.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/... 3. https://eu.usatoday.com/story/travel/flights/todayinthesky/2017/11/07/united-airlines-final-boeing-747-flight-today/838922001/ https://eu.usatoday.com/story/travel/flights/todayinthesky/2... 4. https://eu.usatoday.com/story/travel/flights/todayinthesky/2017/12/19/delta-air-lines-sends-off-its-boeing-747-s-grand-farewell-tour/964101001/ https://eu.usatoday.com/story/travel/flights/todayinthesky/2... 5. https://news.ycombinator.com/item?id=16015304 https://news.ycombinator.com/item?id=16015304 6. https://news.ycombinator.com/item?id=19390633 https://news.ycombinator.com/item?id=19390633

by avar 8y ago

rootusrootus 8y ago

Do you mean a specific variant 747? Because 747s are still definitely flying passengers in the U.S. They are still making new ones.

kenneth 8y ago
747s are not flying any passengers in the US. They are flying passengers to the US. No US carrier still operates the queen of the skies, though that's mostly due to fuel efficiency. Some US carriers had the 747-400 until a couple years ago when United ditched their last one. I loved flying that bird! A few foreign carriers (Korean, Lufthansa) have the much newer 747-8i, which is a lovely plane but hasn't done well commercially due to those same fuel efficiency concerns.
- rwc 8y ago
  But parent alleges that the 747 is outside of certification requirements, which is demonstrably false.
  - inferiorhuman 8y ago
    Neither United nor Delta retrofitted a fuel tank interting system, that's why they retired their 747s earlier than expected. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%20120-98A.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/... Paragraph 2-8 indicates the dates compliance became mandatory (Dec 26, 2017 with a potential one year extension). There are 747-400s flying in the United States, however they've all had interting systems retrofitted, are foreign registered, or both.

rwc 8y ago

"E.g. the reason the 747 was decommissioned from passenger flight in the US when it was is because they flew it right up to the day that the FAA mandated that they couldn't fly it anymore." I'm sorry, what? Do you have a source?

avar 8y ago
In 1996 TWA 800, a 747 flight, exploded[1]. The cause was lack of fuel tank inerting. The FAA subsequently published a rule in 2007[2] saying that by December 26th, 2017 all passenger airliners needed to have an inerting system by manufacture or retrofitting. UA and Delta[3][4] flew such variants of the 747 to within a month of the FAA deadline. The final flight was on November 7, 2017. You can still fly the 747 into or within the US (as e.g. BA does), you just need to have a newer or retrofitted 747. The rule also doesn't apply to cargo planes. Sorry about the "[747] flight[s] in the US" ambiguity. I was referring to the domestic fleet at the time. Also it wasn't literally "right up to the day" of the rule going into effect, but in the grand scheme of things that's accurate enough. The phase-out was planned to coincide with that rule going into effect, among other reasons. The point being that airlines can and will fly airframes that in one way or another would be illegal to manufacture today for safety reasons, or which will be grounded by the regulator tomorrow unless an expensive retrofitting is carried out. I think that's fine, but apparently the fact that airlines are allowed to fly planes with fixable flaws that have "already killed people" just to save some money is surprising to some. It's all a cost/benefit trade-off, and is considered normal by regulators. There's some more details in this HN comment chain at the time in 2017 that I contributed to[5]. Edit: Some weird HN glitch or mod action seems to have happened. My comment upthread is now a top-level comment, but initially I'd replied to the "already killed people" top-level comment by jfk13[6], and that's definitely how it was rendered for a while. 1. https://en.wikipedia.org/wiki/TWA_Flight_800 https://en.wikipedia.org/wiki/TWA_Flight_800 2. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%20120-98A.pdf https://www.faa.gov/documentLibrary/media/Advisory_Circular/... 3. https://eu.usatoday.com/story/travel/flights/todayinthesky/2017/11/07/united-airlines-final-boeing-747-flight-today/838922001/ https://eu.usatoday.com/story/travel/flights/todayinthesky/2... 4. https://eu.usatoday.com/story/travel/flights/todayinthesky/2017/12/19/delta-air-lines-sends-off-its-boeing-747-s-grand-farewell-tour/964101001/ https://eu.usatoday.com/story/travel/flights/todayinthesky/2... 5. https://news.ycombinator.com/item?id=16015304 https://news.ycombinator.com/item?id=16015304 6. https://news.ycombinator.com/item?id=19390633 https://news.ycombinator.com/item?id=19390633