A B-17 Flying Fortress takes part in a 1997 airshow.
CNN  — 

Nine-O-Nine, the vintage plane that crashed Wednesday while carrying aviation enthusiasts in Connecticut, was among 13,000 B-17 bombers produced in the buildup to and during World War II.

Now, only a handful of the Flying Fortresses still take to the air, usually for air shows and special events.

These are the famous workhorse bombers that helped the Allies win World War II.

Thirteen people – 10 passengers and three crew members – were on board when the plane crashed at the end of a runway, authorities said. Seven died, officials said.

“It isn’t the first and we want to make sure it’s the last of this kind of tragedy,” said Connecticut Sen. Richard Blumenthal, advocating scrutiny of what happened.

Nine-O-Nine belonged to the nonprofit Collings Foundation, which uses about two dozen aircraft to educate the public about their role in American history.

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Saving the Flying Fortress
02:43 - Source: CNN

According to the Aviation Geek Club blog, the aircraft was built in Long Beach, California, by the Douglas Aircraft Company. It was accepted into service on April 7, 1945 – too late for combat though used for air-sea rescue duties.

Several years later, the plane was subjected to the effects of atomic test explosions. It was sold as scrap in the mid-1960s and then found a valuable use dropping water and chemicals on forest fires, the blog says. After a restoration, the bomber was sold to the foundation in 1986. It did have a mishap one year later.

In August 1987, while performing at an air show in western Pennsylvania, Nine-O-Nine was caught by a severe crosswind after landing.

“Despite the efforts of her crew, she rolled off the end of the runway, crashed through a chain link fence, sheared off a power pole and roared down a 100-foot ravine to a thundering stop,” the foundation said. The bomber suffered severe damage, though no fatalities.

The aircraft was repaired and featured in countless air shows over the past 30 years, proving it was a true workhorse.

The flight tracking service FlightAware showed dozens of flights in the last few weeks, with stops in Connecticut, Maine, New Hampshire and Massachusetts.

Cabins inside World War II-era B-17 bombers were spartan with few comforts. Here, the interior of the Sentimental Journey.

Aviation geeks, others love to fly aboard a B-17

The website Airplanes of the Past listed 10 airworthy B-17s in the country. Among those still flying in the US are Sentimental Journey, Memphis Belle, Yankee Lady and Aluminum Overcast.

Many are based at museums. Those not so fortunate are long retired to aviation junkyards, destined for a rusty demise.

The ground -- about 2,000 feet below Sentimental Journey -- is visible through the gap between the gun turret and the deck.

Various groups, including the Collings Foundation and Commemorative Air Force, have worked to preserve the legacy of these planes by keeping them flying.

B-17, P-51, and B-24 planes regularly fly to airports around the country for air shows, tours or other events.

Getting aboard a B-17 involves stepping up a short ladder and ducking through a small hatch in the back of the plane. CNN took a flight on the Commemorative Air Force’s Sentimental Journey in 2015.

The iconic nose art on the Memphis Belle.

The Boeing B-17 offers webbed, canvas seats bolted to the side walls of the cabin. They make seating on a small regional jet comfortable by comparison. The four propeller engines are loud.

The waist gunner station – because gunners stand up in the middle of the aircraft – was the most dangerous job on the aircraft because they were so easily targeted.

Combat conditions were uncomfortable at best: no temperature-controlled, pressurized cabins. Imagine trying to fight off enemy planes amid the overwhelming roar and the freezing cold seeping in from outside.

The Sentimental Journey, one of only a few surviving airworthy B-17s.

Despite the windy gaps, the B-17 was named the Flying Fortress for a reason. Its resilient design gained a reputation for taking a beating and still bringing its crew home alive. These refurbished warbirds are as close as most of us will ever come to understanding the horror and stress of aerial combat during WW II.

The first one rolled off the assembly line in 1935. During the war, they primarily flew in the European theater and gained fame – amid heavy losses – for targeting Axis factories, military installations and battlegrounds.

CNN’s Allen Kim, Paul P. Murphy, Holly Yan and Jason Hanna contributed to this report.