Ground Operations
 

The first thing the ground staff do when the aircraft pulls into the gate is chock the main gear. And then place cones in spots around the aircraft like under the wingtips, is this to warn high vehicles of possible collision?

I asume so.

Your replies are welcome:)

cone under wingtips
 

Yes, and sometimes also a rope connecting it to front and back steps if a remote stand (i.e. non airbridge) is being used to prevent passengers venturing under the wings.

Almost...
 

The first thing that happens on arrival (unless MD83 or similar) is that the nose gear is chocked. Once engines shut down and anti collision beacon switched off, the the main gear are chocked (varies on the configuration between companies and aircraft type). The cones are placed to produce a "circle of safety" around the aircraft - equipment is then not allowed to drive between the cone and aircraft - i.e. cones at wing tips SHOULD ensure no-one drives under the wing and so on... not just for high vehicles... additionally if the aircraft is day or night stopping, the cones remain and all equipment is removed outwith the "circle" once all doors etc have been closed

Cheers,
JFF;)