I had the same issue but I found a work around. I use the Auto Shutdown feature mines bound to LWin+End. The auto shutdown goes as far as it can to get an off engine condition. Then tells you what's up in an on screen display. Normally your left power lever will be in the off position but the right power lever is in the idle position and won't move. Bring the left back to Idle and then use the Auto Shutdown key bind again and it should now shut down both power levers and kill the engine for you. Then just radio in a repair request and with the rotor stopped the crew will come.
Hope I explained that correctly? Skal!
PumpChump's post in [MT] Can't repair - Engine supposedly not shut down was marked as the answer