Pratt & Whitney has deep roots in Connecticut, roots that go back to before the Civil War. As a maker of airplane engines, Pratt & Whitney has kept the eagle flying since 1925, building many of the power plants that helped bring us victory in World War II. Today, P&W engines power some of the most sophisticated planes in the U.S. arsenal, as well as the planes of 26 other air forces around the world.But pride alone won’t keep Pratt in business, and it certainly won’t keep it in Connecticut. The company that once employed more than 25,000 people in this state is down to around 9,000, and that number seems to drop every year. Having already shed 1,000 jobs in Connecticut this year — while adding jobs in Georgia and Florida — Pratt recently announced the loss of another 400 salaried positions here. Like any other company, Pratt & Whitney is subject to the vicissitudes of the economy, rising and falling with both the civilian marketplace (as air travel waxes and wanes and as Boeing and Airbus struggle over market share) and with the global market for warplanes. Like any other company, Pratt & Whitney — a component of the global giant United Technologies — also needs to keep costs down.And one way to do that is to move jobs from places like Connecticut, which is seen as an expensive, high-tax, high-regulation place to do business, to places like Georgia and Florida. It certainly doesn’t hurt, when you’re making those kinds of decisions, to discover that those states are eager to cough up millions in tax breaks and other incentives to make the move worth your while.These announcements by Pratt are generally accompanied by statements, no doubt intended to be reassuring, that Connecticut is still important to the company and that it has no plans to leave. Then again, we were also hearing calm reassurances a decade ago, before Pratt closed its Cheshire and North Haven plants.One thing is clear: The good old days — lasting from World War II through the Cold War, when a heavy concentration of defense industries kept this state’s economy soaring, and people could make a good living from factory work — are over. Is there an “on the other hand” here? Perhaps. “The smaller aerospace companies that supply the big companies are busier than ever,” Commissioner of Economic and Community Development Catherine Smith told a reporter recently. And even the big companies will need people to fill high-tech jobs that require more education. Trouble is, those jobs will be less numerous.