Delta Air Lines' effort to acquire Northwest Airlines has the potential to strengthen the South's flagship carrier, improving its odds of survival in an industry that has struggled in recent years. That's good news not just for the airline, its employees and customers, but for all of metro Atlanta.

As one Northwest executive told financial analysts, the proposed acquisition will be a "merger by addition." The idea is that two plus two will somehow add up to more than four, a hope that has often driven airline mergers in the past, but with mixed results.

There's certainly no guarantee this merger will succeed, especially given a cloudy economy, sky-high fuel prices and looming labor issues. But there's very little doubt that Delta and Northwest have a better chance of surmounting those challenges together than apart. There can be strength in size, and millions in cost savings to boot.

In addition, Delta's leaders seem to have worked out a solid deal. If all goes as projected, the merger should keep Hartsfield-Jackson International Airport humming as a significant engine in the local economy.

However, like anxious travelers focusing on flight-status screens, Atlanta will be watching and waiting to see how some factors in the Delta-Northwest equation play out.

For one, what will happen with ticket prices? Basic economics says fewer airlines flying could allow remaining carriers to charge higher fares as consumer options lessen. That could have proved true even if Delta and Northwest hadn't sought to combine, because industry experts say consolidation was coming one way or another. Delta's leadership may well prove smart to have acted decisively and when it did.

Few who don't work for airlines or invest in them relish the possibility of paying more to fly. But for a business community the size of Atlanta, Delta's action should preserve for the foreseeable future the vital Hartsfield hub and its myriad travel choices that help fliers efficiently conduct business around the globe.

Then there's the work force. Like any other business, an airline is only as good as its employees, from CEO to those who greet passengers at ticket counters or make sure luggage gets aboard the right flights. The Delta-Northwest combo faces serious challenges there. As one executive put it, "the finish line wasn't crossed" on all labor issues before the proposed deal was announced.

Delta has reached a deal with its pilots, but Northwest's aviators have announced opposition to the current proposal. But with other airlines announcing bankruptcy and more mergers looming, their negotiating position appears pretty weak.

Job cuts are also a real and continuing concern in an industry that's seen 150,000 jobs disappear since 2001. Delta says it doesn't expect involuntary furloughs of "frontline" workers and will protect seniority as it blends the two work forces.

It's no small feat to combine two large airlines, and hurdles remain. Government regulators and company shareholders must sign off on the deal, and overall, the airline industry's future seems as volatile as the fuel prices we all pay these days.

Under those trying circumstances, Delta seems to have negotiated a respectable deal for itself and the metro region it has long called home.

—- Andre Jackson, for the editorial board (aajackson@ajc.com)