Actually it makes perfect sense. The air thins out as temps rise, so you have less lift at s given speed. If they haven’t tested, they don’t know the safe speeds. They also don’t know the results of greater than normal expansion, which could result in anything from material fatigue to connectors failing. And more.I remember when it hit 122 back in the 90's. They shut down the airport because Boeing manuals didn't have flight data for temps that hot.
Sounds weird, but that's what we were told.
