The Lewiston and Auburn city councils have approved $20,000 to study whether passenger flights should fly from A-L airport.

While the idea seems conveniently tantalizing, the cities must be wary of pursuing a service dependent on a controversial government subsidy to offset the high costs of its operations.

The subsidy is called “Essential Air Service.” It supports passenger flights at Maine airports in Rockland, Augusta, Bar Harbor and Presque Isle. The first three receive $1.2 million annually, while Presque Isle gets $2.6 million.

Enacted in 1978 with airline deregulation, the subsidy’s intent was maintaining rural routes that commercial carriers may abandon. Today, the subsidy is $110 million annually for flights at 105 airports in 33 states and Puerto Rico.

Serious questions about EAS’ value puts the subsidy under regular scrutiny. The General Accounting Office has calculated the subsidy’s rapid growth, from $26 million to $109 million from 1997 to 2007, which made the average government portion of one seat on an EAS flight $98.

There’s devil in these details, though. Subsidized flights fly whether seats are filled – or empty. In January, USA Today investigated federal aviation data and discovered average EAS flights were only 37 percent occupied.

For example, only two passengers, on average, flew on each EAS flight from Lewiston, Mont., to Billings, Mont. in 2006, for a government-sponsored cost of $1,343 per flier.

Potential passenger numbers for Lewiston-Auburn must be much stronger for commercial flights to be viable.

Other concerns exist as well. Getting a subsidy for rural service this close to Portland is questionable. Every EAS airport is more than 70 miles from the nearest “small hub,” as the Jetport is categorized.

If a subsidy is unavailable, this places the impetus on A-L officials and potential carriers to prove passenger flights can offer competitive fares. An unaffordable service is no better than no service at all.

Commercial flights present two unenviable choices: Either subsidize flights through a controversial program often targeted for cuts, or spend millions to compete with a larger airport to the south, and a subsidized one to the north.

This study of passenger service is warranted to decide the issue. A-L might be Maine’s third-busiest airport, but unfriendly skies around the airline industry and rural subsidies make commercial flights questionable.

In the long run, the cities may find there are wiser transportation initiatives to invest in.