Ran a search, but couldn't find anything relating to this.
I recently flew a few sectors with BA (EDI-LHR-HAJ and back)
On the LHR-HAJ sector, I made an observation while we taxied to the runway (27R).
It was 21:55 and therefore dark outside. On our right, using the inner taxiway a BA 772ER pulled along side our A319.
I noticed that there were spot/flood lights illuminating the MLG from the inboard side of one of the outer flap canoes.
It was the first time I had seen a 777 in the dark in the flesh, so this took me by surprise.(I surmised these lights were to aid identification of blown tyres in the dark?)
As our A319 turned onto the active, I noted an Etihad 772ER was sitting at the hold point on the other side (from Terminal 4 I believe), it was also lit up like a Christmas tree, apart from the flood lights for the MLG.
Are the lights for the MLG an option? Or are they fitted to all 777s and the Etihad just didn't have them turned on?
Also, did I surmise their function correctly?