Sehnlichstes gift of my son for Christmas - in addition to the already existing large Quadcoptern - a Nano Quad Copter After the initial charge (45 minutes), the longed-for 5 minutes flight time - the thing rips through our living room - tremendous fun! Unfortunately, after 4 days an engine is defective - and except for nano Quadcopter rotors and battery no spare parts - whether in warranty has opportunities I do not know - the homepage of Revell sound but rather a deterrent than helpful.