Sometimes it isn’t possible to fly when the weather is fine, why ?
![Sometimes it isn’t possible to fly when the weather is fine, why ?](https://www.art-montgolfieres.fr/img/leoblog/b/lg-b-vitessevent.jpg)
Because wind speed - which is not necessarily the same on the ground as in the air - doesn't always allow us to. At wind speeds of over 20 km/h, we have to cancel flights for safety reasons;