For years, the business jet sector was one of the hottest growth areas in aviation. What a difference a global economic meltdown makes.

Business jets, sometimes called private jets – or “bizjets” in industry jargon – is the term used for jet aircraft of smaller size that are used to transport business people or wealthy individuals. These aircraft typically are luxuriously appointed and designed to move passengers in high style.

In 2009, the business jet market got clobbered, with sales of aircraft declining -20% from 2008. It didn’t help matters when, during the auto industry bailout hearings on Capitol Hill last year, CEOs who traveled to Washington, DC to ask for money made the trips in private corporate jets. Lawmakers generated cheap political theater of that fact, prompting many top executives to jettison their planes, or avoid buying them altogether, to avoid a populist backlash.

But that was then; this is now. Political memories are short and the economy is improving – and the business jet market is set to come roaring back. Great money making opportunities in the business jet sector still abound, for those who know how to spot and exploit them.

The best investment play: Bombardier Inc. (Toronto: BBD-B.TO). This Canadian-based plane maker recently unveiled its C-Series business jet, a family of narrow body, twin-engine, medium-range jet airliners. Models are the 110-seat CS100 and the 130-seat CS300.

The elegantly designed, futuristically engineered C-Series boasts a fuel-efficient engine that’s not only environmentally friendly, but a big lure for cost-conscious operators in a world of volatile fuel prices. Advanced composite materials account for nearly 50% of the C-Series aircraft, conveying a 15% lower seat-mile cost and a dramatic reduction in maintenance costs.

The price of business-class jets varies depending on their size. They can run anywhere from $1 million to more than $50 million each. The price of a Bombardier C-Series business jet is $46.7 million.

Between 2004 and 2009, the business jet market was a bloated bubble waiting for a sharp pin. It experienced a torrid growth rate year after year of +15 to +25%, fueled by loose financing. Wealthy individuals and extravagantly paid CEOs rampantly bought private jets, often with borrowed money. Then, the global economy fell off a cliff, taking the business jet market with it.

Now, the stage is set for a dramatic rebound. Brian Foley Associates, an aviation consulting firm in Sparta, N.J., predicts sanguine news for worldwide business jet deliveries during the next 10 years. It sees deliveries rising at a steady +2.7% per year (compound annual growth rate) between now and 2019, with 8,900 business jets worth $170 billion delivered through the period.

These are conservative estimates — future growth could be even higher. Regardless, this time around, the boom stands less chance of going bust, because the players have learned their lessons from the previous wild party. Prospective buyers are subjected to stricter financial qualification; top executives are keenly aware of the need to first make a business case to employees and stockholders for any private jet purchase. Also, aircraft makers are tailoring their production capacity to moderate – i.e., realistic – demand expectations.

The result: this sector is unappreciated by investors right now but, ironically, it faces its best prospects in years for sustainable, long-term growth.

According to another consultancy, Gulfstream International Group (AMEX: GIA) and Bombardier are the business jet manufacturing market leaders (28% and 26.3%, respectively, by value of deliveries), followed by privately held Dassault Aviation (15.9%), Textron’s (NYSE: TXT) Cessna unit (12.7%) and Kansas-based Hawker Beechcraft (8.1%). Brazil’s Embraer (NYSE: ERJ) will have 8.2%, which is up from almost nothing in the last ten years.

Although it’s still too soon to announce a verdict, Bombardier’s new C-Series already is garnering major customers as well as favorable buzz; this family of aircraft could catapult the company to the number one spot.

Before the worldwide economic recession and credit crunch, analysts were projecting outsized growth in bizjet deliveries through the remainder of the decade, with the emerging markets of China, India and Russia as the hottest regions for the industry. Favorable factors included the business community’s growing embrace of business jets as a productivity tool. What’s more, increasingly popular fractional programs — wherein multiple owners share the purchase and overhead — were lowering the cost of entry and ownership.

These inherently strong qualities still apply to bizjets. These days, however, growth expectations for the market are more rational.

For the fiscal year ended January 31, 2010, Bombardier’s revenues decreased -2% to $19.37 billion, but that was largely due to the historically severe slump in aviation, which experienced its worst decline since the Great Depression. With a price-to-earnings ratio (P/E) of 13.8, the stock is now a bargain, considering its long-term prospects.