Here are the reliable domestic airlines in Myanmar.
Sayasan Plaza, Corner of New University Avenue & Sayasan Rd, Bahan, Yangon
Tel : (951) 8604035~38, 09-73256067
Mann Yadanar Pone Airline (7Y)
No.3,7mile, TharYarWaTi Street,
They use ATR 72 or ATR 42 aircrafts made in French. For adult or child, baggage allowance of 20kg is permitted.