Dunno what model Robinson this is and it has been 10 yrs since I flew one but I seem to remember that the OGE on the R1 was only around 3500' at 30 degrees Celsius at MAUW. Surprised me whenI was a noob and learning to operate one professionally. If they were at 6k with 4 on board in Africa it was never going to end well was it? Unless it was a very cold day!