"where e.g. pitot tubes or other sensors are still to be installed, red to make sure that they wouldn´t be forgotten before flight."
Airbus 1: "Toulouse Tower, this is Airbus 1 heavy, we are taxiing out of hangar 10 and are ready to join the queue."
Toulouse Tower: "Airbus 1 heavy, you have been cleared to taxi down kilo to runway 14R. Hold short and await clearance on this frequency."
Airbus 1: "Toulouse Tower, preflight checks are complete, we are standing by for release."
Toulouse Tower: "Good to hear Airbus 1 heavy, at 1 DME
turn right 1-8-0, clear for... Standby Airbus 1 heavy, I see you only have 2 engines and there is red tape all over your fuselage. Are you sure you are ready for this maiden flight?"
Airbus 1: "Standby Toulouse Tower, preflight checks didn't mention anything about tape on the skin of the aircraft... perhaps we should return to the hangar. We would like clearance to taxi to hangar 10."
Toulouse Tower: "Request approved."
I don't think the red tape is there so they will "remember" that they are not finished building the aircraft.
It is probably there to keep out the rain. It seems to be rainy/foggy in every picture taken of this aircraft.
[Edited 2005-01-01 12:26:52]