Airline Comments Due: Thursday is the deadline for comments from airlines and other interested parties on a plan by John Wayne Airport that could open the Orange County facility to more competition. The proposed changes would allow airlines to invite other carriers to share their coveted landing slots at the noise-restricted airport. The changes would also help low-cost, low-fare carriers such as Reno Air begin service even if they cannot win landing slots on their own. They would also permit airlines to put up signs advertising their corporate links to international carriers, even though those carriers do not serve the airport. USAir, for instance, wants to promote its flight connections with British Airways.