Hi there does anyone have a fix for this,

I love my sony wireless headphones and half of the time when im using them at night i switch my phone to flight mode so no one can bug me, the thing is when my phone is in flight mode the bluetooth range goes to about 5cm!?! in normal mode i can just walk around my house with no problems at all and it will reach like 15 metres anyone know a patch for my phone it must be something to do with the bluetooth power output being reduced or something. Please help

thanks