A321
Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance
Flight Crew Took Evasive Action
Aircraft; Human Factors; Airport
My aircraft was pointed east in Taxiway Bravo holding short of Taxiway Uniform at LAX.  It was night time.  While parked behind the hold line I observed what appeared to be a B777 crossing Runway 25R headed North on taxiway Uniform.  LAX ground queried us to ensure we were holding short of Taxiway Uniform. My First Officer ensured him we were holding short of Uniform.  As the B777 began to cross north of 25R we noted his left wing would not appear to clear my aircraft.  I made a call on LAX ground frequency exclaiming something to the effect 'B777 stop; stop crossing RW 25R headed North on taxiway Uniform.'  While attempting to verbally stop the B777 I also turned on my taxi; turnoff and wing takeoff lights. The B777 stopped with his nose onto or very close to taxiway Bravo.  Had the B777 aircraft continued straight or turned east onto Bravo taxiway it appeared that his wing would have impacted our aircraft. In looking at the LAX airport pages I did not see any restrictions on wing length on taxiway Uniform while aircraft are holding short on Bravo. I would suggest that an Ops analysis be made ensuring adequate clearance at the intersection of taxiways Uniform and Bravo at LAX.  If warranted I suggest the hold line on Bravo be moved back to ensure adequate clearance.  I also suggest that intersection be designated a hotspot with a ball note.
While taxiing aircraft east on Bravo we were instructed to hold short of Uniform. I read back that we would hold short of Uniform. As we were coming up on uniform I saw an aircraft crossing 7L approach end on uniform headed towards us. Controller asked verify holding short of uniform to which I replied in the affirmative. As I was looking at the approaching plane (a B777) it looked to me that the B777 wing was not going to clear our plane when they're in the right turn ahead of us on bravo taxiway. I indicated this to my captain. Frequencies were jammed I asked the captain to flash all lights to stop the B777 as I thought we might get hit. The captain flashed lights and keyed on frequency to stop the B777. Fortunately they stopped. Nothing on [the] charts or the taxiway itself indicates a special stopping point. We were emphatically short of uniform but would not have been clear of the B777 wingtip on a turn. It seems when crossing a northbound plane on uniform to turn eastbound on bravo the hold short point for us should have been further west of uniform. I would love to know what we could have done differently/better.
An A321 Flight Crew; holding short of Uniform on Bravo at the ILS critical hold bars; east bound; experiences a near collision with a B777 northbound on Uniform. Flashing lights by the A321 crew get the B777 stopped in time to avoid a collision.