The pilots were accompanying teenagers flying a homemade plane across Africa when their aircraft crashed.
Two South African pilots involved in a project for teens to build a homemade plane and fly it across Africa have died in a crash in Tanzania.
Des Werner and Werner Froneman were in a small plane supporting teenagers who last month flew a homebuilt aircraft from Cape Town to Cairo.
The pilots had planned to travel from Uganda to Malawi ahead of their return to South Africa on Monday, but requested to land in Tanzania on Saturday after reporting engine problems, said Hamza Johari, Director General for the Tanzania Civil Aviation Authority.
The light aircraft landed at Tabora in central Tanzania and after the pilots thought the engine problem had been fixed, they departed again. The plane crashed five minutes after takeoff.
"They sorted out the problems and took off but after five minutes they reported a similar problem and requested to return," Johari said.
U Dream Global, a South African organization behind the Cape to Cairo project, said it was devastated by the news.
"U Dream Global: Cape to Cairo Challenge is devastated to report that there has been an accident of the flight support aircraft and that the project directors, Des Werner and Werner Froneman, have lost their lives," it said in a statement on Facebook.
U Dream Global was founded by teenager and motivational speaker Megan Werner, Des Werner's daughter.
The Cape to Cairo project took 20 inexperienced teenagers from different backgrounds and taught them how to build a Sling-4 aircraft in three weeks. In early July, the crew completed the 12,000 kilometers (7,445 miles) trip from Cape Town to Cairo.