If you happen to be flying into Changi International Airport, Singapore on runway 02L and you’re seated on the port side of the passenger plane, look outside the window just as the pilot flares for touch down and you’ll see a large bunker just beyond the airport perimeter.
Located inside Changi Airbase (East), the same spot used to house sheds for fighter aircraft and sometime in the first quarter of 2014, the place was razed and work commence to build the hardened aircraft shelter (HAS). Construction work seems to have been completed recently and the top of the structure is now covered with earth and vegetation.
The entrance to the HAS is approximately 33 meters wide, large enough to fit the G550 AEW aircraft from the Republic of Singapore Air Force’s 111 Squadron.
There is another HAS of such enormous dimension and it is located on the western side of Tengah Airbase. Work on that structure started in late 2008 and took much longer to be completed. A large HAS is necessary as the E-2C, with its folding wings, was phased out in favor of the G550 AEW and the business jet has an enormous wingspan.
Based on Google Earth satellite imagery, the design of both HAS is the same with a large shaft at the back of the shelter to channel hot exhaust from the aircraft engines out of the building.
By Alert5 (Own work) [CC BY-SA 4.0], via Wikimedia Commons