Yes, this is a thing that can happen. When temperatures are high the air density means that planes need to achieve a higher speed to take off. Same for increased weight. Same for high altitude airports. Same when there’s less headwind to take off into.
If enough of these factors are bad enough, you have to change what you can. Can’t change the airport elevation or the weather, so that leaves you with the weight.
isnt hot air less dense than cold air ?
Yes, less air means less lift. Same issue with altitude.
It also means less air, as in density, so the fans and compressors are able to pull in less air to burn with. The fadecs compensate for this automatically but it means the output is derated till you get far enough off the ground to get speed.
i see. that makes sense now. thanks.
Good they did that. I’d probably would be one of those volunteers.
Probably better than doing it mid flight.