HELP.. Heli Not powering DOwn

[Spikey]

Hi the last 3 flights my heli wont power down, its fyling perfectly, well trimmed and all of a sudden mid flight I go to power down and it wont, the right stick function still work but the throttle does nothing so I have to quickly catch it before it hits anyting. Its fine for the 1st 2-3 mins but then it happens, if I catch it turn off and on its fine again for a few mins, it was fine up until today Any ideas?

thanks

[Boggy]

sounds like your 4in1 is up the shute mate

[Spikey]

its new.... I noticed the other issue is when its flying sometimes it sounds like the motors are going into overdrive for a split second with a high pitch wurling noise.