צפו בסרטון מצויר בחינם When to call it a day

See our struggles to get off the ground at the Mannlichen (near Interlaken, Switzerland). Only the most experienced pilots did manage to take off that day. And we ignored this simple rule: when there are no local pilots going up ... maybe it's not flyable.
On a more serious note: at the Mannlichen you have to pay to go down by cable car/train. This puts pressure on you to fly which is thus a threat to your security.
BTW: Sorry for Yakety Sax, but it just had to be put under this video.