Airline food shows a growing divide between premium and coach class

Airplane food is often disgusting. After paying hundreds (or thousands) of dollars for a flight, passengers are served sad trays of rubbery chicken, powdered mashed potatoes, and tiny iceberg salads with ranch dressing.

Now there's a growing movement from US airlines to do better - for first class and business passengers, at least.

When American Airlines recently launched a 15-hour direct flight from Los Angeles to Sydney, Australia, it also debuted a new menu. Flight attendants offer first-class passengers complimentary glasses of 2010 Penfolds Grange Shiraz (normally $850 per bottle) and roasted sirloin steak with red wine sauce.

Travelers in the economy cabin are still only treated to peanuts (They will, however, get complimentary spirits or wraps and chips on coast-to-coast flights starting May 1).

The improvements in first and business class have more to do with the economics of the airline industry than they do with a desire to provide better service, Richard Foss, culinary historian and author of "Food in the Air and Space: The Surprising History of Food and Drink in the Skies," tells Business Insider.

Foss has studied the history of airline food for over a decade, from the glory days in the '70s when airlines served lobster to today's inflight tuna sandwiches. Here's a look at that history, and how airlines are trying to bring back the golden age of airline dining for high-paying passengers.