Friend of mine in an A320 was minding his own business in the cockpit and he had his head-set on. A ground-handler walked to the external jack and plugged in his own head-set. An intensely loud piercing electronic squeal went directly through the captain's ear-phones as the ground handler plugged in and the captain's hearing was so badly damaged that he lost his licence for several years. Hand signals do have their advantage at times like these...
Your winding me up , try having your retina's burn't out by the over paid sky jockey , when he can't get an answer from his headset man , so flashes his nose wheel lights instead !!!!!!
Brilliant !!!! as for hand signals ONLY when lightning is about or Headset fails and no replacement to hand !!! .....