The French billionaire and politician Olivier Dassault has died in a helicopter crash in Normandy. The 69-year-old rightwing MP was the grandson of Marcel Dassault, who founded the aircraft manufacturing company Dassault Aviation. The French president, Emmanuel Macron, paid tribute to Dassault, tweeting that he “loved France”. “As a business leader, MP, local councillor, a reserve commander in the air force, throughout his life he never ceased to serve our country, to promote what was great about it. His brutal death is a great loss. Our thoughts go to his family and his friends,” Macron wrote. The helicopter transporting Dassault crashed shortly after taking off from the Normandy coastal resort of Deauville, where the tycoon had a holiday home, at about 6pm on Sunday. The cause of the crash, in which the pilot was also killed, was not immediately known. The Dassault family boasts one of the biggest family fortunes in France. Olivier Dassault was the eldest of the four children of Serge Dassault; he inherited his father’s estate along with his two younger brothers and sister in 2018. He was reported to have a personal fortune of about €6bn (£5.2bn). He was a keen photographer and had been MP for the Oise department in northern France for the centre-right Les Républicains (LR) since 2002. Damien Abad, president of the LR group in the French National Assembly, said Dassault was a man with “a big heart who was a great defender of industry”. “His kindness and humanity will remain forever in our memory,” Abad tweeted. The French air accident investigation bureau (BEA) reported that the aircraft, an Aérospatiale AS350 Écureuil, had crashed “on take off” from a private ground. The BEA has opened an inquiry and said it was dispatching five investigators to the scene. The French justice minister, Éric Dupond-Moretti, wrote on Twitter that he was “extremely saddened” by the death. “The Republic has lost one of its great servants,” he said.