The EC130 Eurocopter crashed crashed after leaving Lausanne airport in Switzerland, heading for the eastern French town of Montbéliard, on Thursday morning.
Eyewitnesses said it fell "like a stone" from the sky into the garden.
Of the seven people on board, five died, one more suffered multiple injuries and the condition of the seventh, whom rescuers were trying to free from the wreckage, was not clear late on Friday morning.
Six of the passengers, all of whom were Swiss, were man and one was a woman.
Emergency services rushed to the scene of the crash in Bart, a few hundred metres from Montbéliard aerodrome.