Robert Herbst, airline analyst and founder of AirlineFinancials.com, estimates the five US passenger airlines with European operations are collectively losing $35.8 million in revenue per day since Friday, April 16 (losses for Thursday, April 15 and the start of the European shut-down are estimated at $17 million). 
 
After accounting for savings from unused fuel, landing fees not paid, lower labor costs, less maintenance, etc. the estimated operating loss for all five airlines comes to approximately $21.9 million per day with half that amount for Thursday. Because Delta has the highest amount of traffic to/from the closed European airports, they will incur the largest losses with United not far behind.
 
As long as European airports remain closed, AirlineFinancials.com estimates the following daily losses for each of the US airlines.

• Delta (DAL) - $10.4 million loss in revenue with an operating loss of $6.5 million.
• United (UAUA) - $8.4 million loss in revenue with an operating loss of $5.2 million.
• American (AMR) - $7.6 million loss in revenue with an operating loss of $4.6 million.
• Continental (CAL) - $5.6 million loss in revenue with an operating loss of $3.4 million.
• US Airways (LCC) - $3.7 million loss in revenue with an operating loss of $2.2 million.

In addition to the above, JetBlue (JBLU) is likely losing a relatively small amount of passenger feed to/from their European partners.