A closer look at the legendary B-17 Flying Fortress

The Boeing B-17 Flying Fortress first flew in July, 1935. By the end of WWII, nearly 13,000 were built.

For more about this incredible plane, check out  WWII icon: A closer look at the legendary B-17 Flying Fortress.

Boeing's Model 299, the precursor to the B-17.

Though best known for flying daylight bombing missions over Europe, the B-17 was used in every theater of the war.

Like all WWII aircraft, the B-17 was modified and improved during the war. This earlier variant lacks the chin turret of the later G variant.

This is an early, and rare, D variant. Note the different tail shape and belly gunner structure, the lack of a tail gunner and how there are fewer guns overall.

This specific aircraft, the "Swoose," saw combat in the Pacific. It's the oldest surviving B-17 and the only surviving D variant. It's under restoration at the National Museum of the Air Force in Dayton, Ohio.

Depending on the mission, the B-17 would carry between 4,500 and 8,000 pounds of bombs (2,000 to 3,600kg).

B-17s flew in tight formations to protect each other from attacking Axis fighters.

B-17s of the 398th Bombardment Group heading toward Neumunster, Germany, on April 13, 1945.

The B-17 had a maximum speed of 287 mph (462 km/h), but its normal cruising speed was around 182 mph (293 km/h).

Vapor trails of B-17s flying in formation.

A formation of B-17s dropping bombs over Europe.

B-17s of the Eighth Air Force dropping their payloads over railroad yards in Donauworth, Germany in April, 1945. The smoke is a signal marker from the lead plane to signify it was time for the other aircraft to drop their bombs.

The B-17F "All American III" limping its way back to base in North Africa after a midair collision with a Bf 109. Amazingly, none of the crew were injured. 

From the National Archives: "Lt. M. J. Bleakman, 0-724064, Baltimore, Maryland (right) makes final inspection of B-17 Flying Fortress before piloting Hampton Roads Port of Embarkation Historical Staff over the Port Area."

The only airworthy B-17 in Europe, the "Sally B," was used in the filming of the 1990 film Memphis Belle.

The Sally B was built in Burbank, California in 1945 and now lives in Duxford, UK.

Though not particularly big by today's standards, the B-17 was one of the larger aircraft of WWII. Seen here is a B-17 beside some modern civilian aircraft at the Imperial War Museum Duxford.

The "Shoo Shoo Shoo Baby" in 1988 after a 10-year restoration to airworthiness.

Because of their size, not many museums can fit large bomber aircraft like the B-17.

Many of the B-17s in museums are aircraft that never saw combat. The Castle Air Museum in Atwater, California has one that was used as a training aircraft. It's painted in remembrance of one shot down over the North Sea.

Not surprisingly, Boeing's Museum of Flight in Seattle has an example, a rare F variant. Built nearby, it served as a trainer aircraft and was stationed in Britain at the end of the war. It didn't see any combat, but was later used as a tanker and even appeared in movies such as 1970's Tora! Tora! Tora! and Memphis Belle.

Only a handful of B-17s are still flyable. The Planes of Fame museum in Chino, California is restoring one to airworthy condition.

This example was a trainer after WWII.

It appeared in TV show Twelve O'Clock High as the airplane Piccadilly Lilly.

The distinctive chin turret marks this as the final G variant.

It's very rare to be able to go inside a B-17, but this one is open most weekends.

The pride of the Palm Springs Air Museum is a B-17G named "Miss Angela," which you can go inside.

A look up into the bomb bay.

After squeezing through the small hatch to get inside, you've got a great look at the bombardier station. 

You can watch a 360-degree video of this view right here.

The view from the dorsal gun turret, just aft of the cockpit.

It's a tight squeeze through the bomb bay to the rest of the aircraft.

There's a surprising amount of space here, though I imagine it'd seem a lot more cramped with the crew on board in all their gear.

With the "skylight" removed, and if you're tall enough, you can pop up and take a gander down the wings.

The view forward through the bomb bay toward the cockpit.

The Palm Springs Air Museum has done a fantastic job of not only restoring the aircraft, but also including much of the in-period gear and tech.

In this view forward, you can see the top of the ball turret and the starboard waist gunner's position.

Only some models had plexiglass windows here. I can't imagine how cold it was.

Vitally important, but what a place to be. 

The incredible Pima Air and Space Museum in Arizona, easily one of the best air museums in the world, has a number of famous bombers. The "I'll Be Around" sits in its own hangar, unlike most which sit outside in the brutal desert sun. This aircraft was first registered to the US Air Force, then served in the Navy, Coast Guard and with various private owners including as a fire-fighting air tanker. 

Most B-17s were stationed in Britain during the war. Not surprisingly, there are some in the air museums there, like this G variant at the Royal Air Force Museum in London.

This aircraft was built in July, 1945, in Long Beach, California. It was one of the last B-17Gs built by Douglas.

Like all surviving B-17s, this one has an extensive and varied history. It was a search and patrol aircraft, a water bomber and more. It actually flew to the UK from the US in the early '80s.

Each version of the B-17 had four radial engines that in final form generated a total of 4,800 horsepower.

The view out the front bubble.

Here's the most famous Boeing B-17, the "Memphis Belle," headed back to the US on June 9, 1943, after completing 25 missions over Europe. 

For more about the incredible B-17, check out WWII icon: A closer look at the legendary B-17 Flying Fortress.