Mr Tappenden, 28, was reunited with his parents after flying to Gatwick airport at 5.46am on a British Airways flight from Nairobi, Kenya.
He had travelled to Uganda for an adventure holiday with fellow Briton Martin Friend, who became one of the four Britons among the eight Westerners murdered by a band of interahamwe Hutu militia.
Mr Tappenden and his father Robert, who met him at the airport, arrived at the family home in Hayes, Kent, just before 7am. As they pulled into the driveway his mother, Pearl, came out to greet them.
Robert Tappenden said: "We are all very glad to have Gary home. Gary is very traumatised ... He is obviously relieved and pleased to be home. He is very distraught at the loss of his mate and other friends."
The Britons who died were Steven Roberts, 27, from Edinburgh, Joanne Cotton, 28, from Essex, Mr Friend, 24, from Orpington, Kent, and Mark Lindgren, 23, from St Albans, Hertfordshire.
A three-member team of Scotland Yard detectives arrived in Uganda yesterday to help local investigations into the murder of the eight tourists.Reuse content