Emergency landing NH37 2017/8/12 Sudden decompression Oxygen mask falling During the climb, it stopped climbing at about 16000 feet and started descending very slowly. As the nose turned to Boso Peninsula, I thought I would return to Haneda Airport and prepared a camera to record the announcement.Then, the oxygen mask came down suddenly. It was thought that the altitude was about 12,000 feet, and I thought it was a malfunction of the oxygen mask, but I knew that the captain's announcement had caused a decompression problem. About 20 minutes after the trouble, I landed safely at Haneda Airport. Watch a landing video of a fire engine waiting at the airport.