I believe the last 5 frames of their order due 2017 are meant to replace the early frames, as they will be 10 years old. Is that correct? If so, there may not be the "20th frame" of Singapore Airlines A380s.
Singapore Airlines flight SQ317 from London to Singapore diverted to Baku, Azerbaijan due to cabin depressurisation. Oxygen masks were deployed and the aircraft landed safely. There were no injuries to the 467 passengers and 27 crew on board. Passengers on board reported hearing a decompression noise, along with claims that a door seal on the front door was damaged.
The Air Accident Investigation Bureau of Singapore has released an update on the incident. A slightly worn seal was found on the door in late December and maintenance was deferred for up to the maximum allowable limit of 120 days. On the flight to London on the incident date the issue was raised and upon landing in London another inspection was carried out. On the flight back to Singapore, the cabin crew once again noted an increase in noise around the door. 5 hours into the flight the cabin pressure slowly increased from 6000 feet to 10000 feet and the flightcrew declared an emergency and diverted to Baku. avherald.com/h?article=46e1dcdb/0000&opt=0 www.mot.gov.sg/news/Airbus-A380-Diversion-to-Baku-Azerbaijan-Investigation-Update.pdf