Let us say that an airline has 100 airplanes. Due to lack of demand the airline parks 30 aircraft. The airlines lays off some employees and saves some costs. But the station costs can only be cut back a little. The finance costs continue. ETC,ETC, Can you understand how this airline could be running at 95% capacity and still lose money? Im not saying this is United's situation because I dont know. But it is possible.
Airlines are such a leveraged business. I remember in a stock market class years ago discussing Eastern Airlines. They had a lot of debt, The fixed cost were enormous, but if they could have just added one, just one, passenger, their profit would have gone up 50%. Cant remember the exact number , its been a long time. Good luck UAL.