The event took place on No.10.2011 at night about 23:30 local time above Bangkok. I was in flight 053 BKK to TEH, a few minutes after take off I noticed a trianglular shaped object flying in opposite direction. It's shape could be recognized just by three red lights located apart. At first, I assumed it was an aircraft but as our plain increased its altitude the flying object got more definable by city lights coming into context. It was totally transparent hence I could see city lights through it. This object could only be detected by presence of those three red lights.