On Saturday, 24 April 2021 at 20:12:48 UTC+1, Tom BravoMike wrote:

Do you really believe Klaus Ohlmann and Jean-Marie Clément would have set their records in the Andes in a "pure" sailplane? Instead, they flew each a Nimbus 4DM, I believe. "No safety advantage" - really? Will you say it's a special case? Well, it is a sort of competition in setting records.


Well I remember reading an article by Klaus Ohlmann after his first distance record in the Andes. That one was in a Stemme, and I remember he said if he had wanted to use the engine he would have had to land first and give it time to warm up, because it was too cold to use after a long time at altitude. So a convenience feature, not a safety feature.

I don't know why he subsequently changed to a Nimbus 4 - did it have anything to do with what generous people were willing to lend him? Even with the Nimbus, the engine might not have started after a few hours at 20,000 feet.

On the subject of warming up time, with my Solo engine I was advised by Shempp-HIrth to take off without waiting for it to get to 40 degrees C (that is what the manual specifies) because a cold engine develops more power. I generally take off as soon as I have completed the ignition etc checks, and if I start over a field I go to climb power very soon. I remember in his guide Eric mentions taking a better look at the field which you didn't have to land in while the engine warms up a bit before increasing power and climbing away.