These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.The goal is to fix all broken links on the web . Crawls of supported "No More 404" sites. ||||| Air China pilots have been placed under investigation following claims they caused a flight to suddenly plummet 25,000 feet because they were smoking in the cockpit. 
 
 During the Hong Kong to Dalian flight on Tuesday evening, the plane suddenly lost pressure and dropped around 25,000 feet, from 35,000 feet to 10,000, within ten minutes, according to flight data. 
 
 Some passengers onboard the flight pulled out their phones as the oxygen masks dropped from the ceiling and posted the images to Chinese social media after the incident. “The announcement from the cockpit said the ability to increase oxygen in the cabin malfunctioned so the plane lost pressure,” one wrote on Weibo, a popular Chinese social media platform (via South China Morning Post). 
 
 Reuters 
 
 Pilots onboard the flight managed to successfully level the plane and continue its journey, arriving safely in Dalian shortly afterwards with no injuries reported. The Air China flight CA106 was transporting 153 passengers and nine crew members. 
 
 After the incident, several Chinese state-owned media outlets revealed that the sudden drop in altitude was believed to have been the result of pilots accidentally turning off the air-recycling fans while they were smoking in the cockpit mid-flight, reported CNN. Smoking onboard a flight is against aviation regulations. 
 
 When crew found out that the fans had been turned off, they allegedly immediately switched them back on and bought the plane back to around 24,600 feet. 
 
 On Wednesday, Air China admitted that their pilots were being investigated by the Civil Aviation Administration of China. "If the investigation discovers crew behaviors that have violated rules and regulations, we will adopt a zero-tolerance attitude and seriously punish those found responsible," the airline said in a statement. 
 
 Hoby Sun, a passenger on the plane, told CNN that people did not seem to panic during the incident. "I didn't think too much of it at the time—we didn't know what was going on, nor did the flight attendants it seemed," he said. "I'm not physically hurt, but the psychological impact lingers. When I close my eyes, I see the oxygen masks dangling in front of me." 
 
 Air China did not immediately respond to Newsweek’s request for comment. ||||| Air China has placed the pilots of a flight from Hong Kong to Dalian under investigation after claims of aircrew smoking in the cockpit, causing the plane to lose altitude mid-flight. 
 
 In a statement released just over 24 hours after the incident, the national airline vowed "zero tolerance" if crew members were found guilty of wrongdoing. 
 
 Flight CA106 dropped 25,000 feet in 10 minutes on Tuesday night, flight data showed, triggering the release of oxygen masks from the cabin ceiling. The aircraft did not divert and continued on its journey, landing safely in the northern port city of Dalian in China's Liaoning province. 
 
 At least two passengers posted photos and videos on social media showing those on board wearing masks but looking calm. 
 
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 One, writing on Chinese microblogging platform Weibo, said: “The announcement from the cockpit said the ability to increase oxygen in the cabin malfunctioned so the plane lost pressure.” 
 
 According to tracking website FlightRadar24, the 159-seater Boeing 737 suddenly began descending at 7.40pm between Shantou and Xiamen, half an hour after it took off from Hong Kong International Airport. 
 
 An announcement was heard over the cabin speakers saying the aircraft was carrying out an emergency descent due to cabin decompression. 
 
 Similar data from aviation company Flight Aware indicated an initial drop of 14,100 feet in four and a half minutes. The Flightradar24 data shows the plane descended from 35,000 feet to about 10,000, at which point the aircraft levelled off and began climbing to cruising altitude soon after. 
 
 The Weibo user posted a photo of himself in a mask and giving a thumbs-up sign, saying the issue had been resolved as the plane approached Xiamen. 
 
 The aircraft then continued to Dalian, the flight lasting three and a half hours. 
 
 Hong Kong’s Civil Aviation Department said it had no information on CA106 from after it left the city’s airspace. 
 
 The Communist Party's media mouthpiece, the People's Daily, said the crew were suspected to have been smoking in the cockpit. 
 
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 Addressing the claims of misconduct, Air China confirmed the pilots were under investigation by the Civil Aviation Administration of China (CAAC). 
 
 "If the investigation reveals that the crew has violated regulations, the company will seriously deal with the responsible person with zero tolerance," Air China said on Weibo. 
 
 The CAAC could not be reached for comment. No reports of injuries have surfaced. 
 
 Cathay Pacific Airways pilot and air safety expert David Newbery, who is also president of the Hong Kong Airline Pilots Association, said aircraft undergoing depressurisation may not be required to divert. It was sometimes safe to fly in the event of equipment failure, but a structural issue required landing at the nearest airport, he said. 
 
 “The norm would usually see an aircraft suffering from depressurisation landing at the nearest suitable airport – not least to calm down the passengers, who would be severely frightened,” Newbery said. “However, if there were nothing structurally wrong with the aircraft, the commander could elect to continue to a more distant airport.” 
 
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 Another professional pilot, with more than 25 years of experience, said any depressurisation of the cabin would prompt the pilots to descend to 10,000 feet, as they did in this case. 
 
 “That is what is considered a safe, breathable atmosphere for the passengers, and then the captain has to make a decision,” he said. 
 
 “I would say in just about every case, you would want to land as soon as possible. But it depends on what happens in the plane and what the pilots’ checklist says. 
 
 “In most cases you would have declared an emergency on the way down and then you would have landed at the most suitable airport.” 
 
 The Boeing plane used for CA106 is registered as B-5851 and is four years old. As of Wednesday afternoon the aircraft remained on the ground at Dalian airport. Some Wednesday flights operated by Air China were cancelled, including the 7.45am departure to Beijing, which is usually carried out by the plane serving flight CA106. 
 
 Hong Kong’s Cathay Pacific has an 18.13 per cent stake in Air China, which itself holds a 30 per cent stake in Cathay Pacific. 
 
 Air China and its sister airlines operate a fleet of 655 aircraft, according to the company’s 2017 annual report. ||||| SHANGHAI (Reuters) - An emergency descent by an Air China aircraft after cabin oxygen levels dropped has been linked to a co-pilot smoking an e-cigarette during the flight, state media said on Friday, citing China’s aviation regulator. 
 
 The state-backed Air China Boeing 737 aircraft was flying to the Chinese city of Dalian from Hong Kong on July 10 when it dropped to 10,000 feet (3,048 m), with oxygen masks deployed. Then it climbed again to continue to its destination. 
 
 Chinese airlines have a good safety record in general, but passengers have, on occasion, accused pilots of smoking during flights. Few such incidents have been confirmed, however. 
 
 “In the preliminary investigation, the co-pilot was found to be smoking an e-cigarette,” state-owned China News said, citing a news conference by the Civil Aviation Administration of China (CAAC) investigating Tuesday’s incident. 
 
 “Smoke diffused into the passenger cabin and relevant air conditioning components were wrongly shut off, without notifying the captain, which resulted in insufficient oxygen,” it quoted Qiao Yibin, an official of the regulator’s aviation safety office, as saying. 
 
 China News said the co-pilot had shut off the air conditioning units. 
 
 Qiao said the shut-off triggered an alarm, prompting the crew to perform an emergency pressure relief procedure, which then released the cabin’s oxygen masks. 
 
 The crew realized the problem after the descent and restored the air conditioning, allowing cabin pressure to return to normal, he said. 
 
 The CAAC said it was continuing the investigation and was analyzing the aircraft’s flight data recorder and cockpit voice recorder. 
 
 Air China said it would terminate the contracts of the employees involved in the emergency descent incident, and suggested that the CAAC cancel their licenses, it said on its official account on China’s Twitter-like Weibo on Friday. Air China also said in a previous Weibo post on Wednesday it had a “zero tolerance” approach towards wrongdoing by any crew. 
 
 The incident featured heavily on Chinese social media on Friday, with some commentators demanding harsh punishment and revocation of the pilot’s flight license. 
 
 China’s aviation regulations, which bar flight crew from “smoking on all phases of operation”, also banned passengers from using e-cigarettes on flights in 2006. 
 
 Users of online airline forums have occasionally accused pilots of smoking during flights, however.In 2015, government-run China National Radio said four passengers on an Air China flight from Hong Kong to Beijing smelt strong smoke emitted from the cabin. 
 
 In 2016, the United States prohibited the use of e-cigarettes on commercial flights.
– "When I close my eyes, I see the oxygen masks dangling in front of me." That's the lingering anxiety of a passenger on a recent Air China flight that plummeted thousands of feet after oxygen levels dropped. A senior official from the Civil Aviation Administration of China tells CNN the reason for the descent stems from a co-pilot smoking an e-cigarette. The official says the pilot tried to shut off air-recycling fans so the vapor wouldn't reach the cabin, but "toggled the wrong switches," causing air pressure to drop. After the plane fell Tuesday during a three-hour flight from Hong Kong to the Chinese city of Dalian, pilots were able to bring the plane back to around 25,000 feet, and it landed safely. Various sources are listing different numbers for how far the plane actually dropped, but flight data cited by Newsweek shows an approximately 21,000-foot decrease over 18 minutes. Per the South China Morning Post, a couple of the passengers posted pics and video on social media showing people donning the oxygen masks that came down, though the mood was relatively calm. "The announcement from the cockpit said the ability to increase oxygen in the cabin malfunctioned so the plane lost pressure," one wrote on Weibo. Reuters notes that even though China's airlines have a pretty decent safety record, pilots are sometimes accused by passengers of smoking during flights. China bars flight crews from "smoking on all phases of operation," and passengers there haven't been able to use e-cigarettes on planes since 2006. Air China says it will "adopt a zero-tolerance attitude and seriously punish those found responsible," depending on the results of the CAAC's probe.