The B-17 Flying Fortress and Checklists (#319)

Apple released the first two episodes of Masters of the Air on Friday and both were excellent. I give it ⭐️⭐️⭐️⭐️⭐️. One of the stars of the show, of course, is the B-17 Flying Fortress. Want to know more?

History of the Development of the B-17

The development of the Boeing B-17 Flying Fortress began in the early 1930s when the United States Army Air Corps sought a new long-range bomber capable of high-altitude operations. Boeing's response to this requirement was the Model 299, a revolutionary aircraft that featured four engines, retractable landing gear, and a fully enclosed bomb bay. In October 1935, the Model 299 took its maiden flight, showcasing its advanced design and impressive capabilities. Despite a crash during the evaluation phase, the aircraft demonstrated exceptional performance, leading to the Army Air Corps ordering 13 production models.

In 1936, the B-17 entered service as the B-17B, marking the beginning of a series of modifications and improvements. The Flying Fortress quickly evolved to address the changing needs of the military and the war, with each subsequent model incorporating advancements in technology, armament, and defensive capabilities. In total, between 1935 and May of 1945, 12,732 B-17s were produced. During World War II 4,735 B-17s were lost during combat missions (37.2%).

The B-17E was an extensive revision of the Model 299 design. The fuselage was lengthened by 10 feet and a gunner's position was added in the redesigned tail which eliminated a blind spot. The nose (especially the bombardier's well-framed nose glazing) remained relatively the same as earlier -B through -D versions, but featured the addition of an electrically-powered and manned dorsal gun turret just behind the cockpit. The US built 512 E Models with the first one rolling off the production line in September 1941.

The next model, the B-17F, added the manned Sperry ball turret for ventral defense, along with an enlarged, nearly frameless Plexiglas bombardier's nose enclosure for better forward vision. The Mighty Eighth Air Force relied upon this version for almost all of the bombing against Nazi Germany in 1943. Boeing produced 3,405 of these planes starting in May 1942. However, the B-17F lacked adequate defense against a head-on attack. In September 1943, Boeing tested a new chin turret.

The success of the new chin turret, along with other improvements, led to the development and delivery of the B-17G with the first rolling off the assembly line in August 1943. The Bendix chin turret is the most obvious improvement incorporated into the B-17G design which helped to defeat head-on attacks by the Luftwaffe. Boeing built 8,680 B-17Gs during the war.

B-17G Specifications:

• Crew: 10 consisting of the pilot, co-pilot, navigator, bombardier/nose gunner, flight engineer/top turret gunner, radio operator, right waist gunner, left waist gunner, ball turret gunner, and tail gunner

• Armament: 13 .50-cal. machine guns; normal bomb load of 6,000 lbs.

• Engines: Four Wright Cyclone R-1820s of 1,200 hp each

• Maximum speed: 300 mph

• Cruising speed: 170 mph

• Range: 1,850 miles

• Ceiling: 35,000 ft.

• Wing Span: 103 ft. 10 in.

• Length: 74 ft. 4 in.

• Height: 19 ft. 1 in.

• Weight: 55,000 lbs. loaded 

Precision Bombing

The key to the B-17 being able to deliver its bombs accurately on the target (known as “hitting the pickle barrel”) was the Norden Bomb sight. The Norden bombsight was a tachymetric bombsight that combined an analog computer that constantly calculated the bomb's trajectory based on current flight conditions and a connection to the bomber's autopilot that let it change the bomber’s flight path based on changing wind or other effects. Together, these features allowed for unprecedented accuracy in daylight bombing from high altitudes as long as the target was visible. However, bombing is a complicated proposition. Where the bomb hit is a function of the direction and speed of the airplane at the moment of release, the aerodynamics of the projectile, and the wind and atmospheric conditions while the bomb iss in flight. The B-17 bombardier looked through the telescope of the bombsight to find the target somewhere ahead, then made adjustments to compensate for the effects of wind drift and the speed of the airplane. He then fixed the target in the crosshairs, and flew the airplane to the automatically calculated release point by the link from his bombsight to the autopilot.

I know most people aren’t big fans of math but here is a good example of the challenges of dropping an unguided bomb onto a target. For instance, if there is a B-17 Flying Fortress flying at 160 mph at 23,000 feet and dropping a 600-pound bomb to try to hit a target. The bomb has to be released 8,875 feet (over a mile!) from the target. The bomb will be in flight for 38 seconds. If the speed calculated for the airplane was off by two miles per hour and the altitude wrong by 25 feet the bomb would land 115 feet from where it was supposed to land. The limited yield of the bombs also added to the challenges. A 500-pound bomb, standard for precision missions after 1943, had a lethal radius of only 60 to 90 feet. It dug a crater just two feet deep and nine feet wide. With bombing accuracy measured in hundreds of feet, it took a great many bombs to get the job done.

In 1943, Eighth Air Force bombing accuracy was terrible. The average circular error in 1943 was 1,200 feet, meaning that only 16 percent of the bombs fell within 1,000 feet of the aiming point. As historian Stepohen McFarland said “the Eighth Air Force bombardiers were having trouble hitting the broad side of a barn,” let alone a pickle barrel.

Nobody tackled the accuracy with more initiative than Colonel Curtis E. LeMay, commander of the 305th Bombardment Group of the Eighth Air Force at Grafton-Underwood, Britain. He identified the best bombardiers, made them “lead bombardiers” for the formation, and had all of the aircraft drop their bombs when the lead bombardier did. He also mandated that all bombers fly straight during their bombing runs. As a result, AAF bombing accuracy improved. By 1945, Eighth Air Force was operating at much lower altitudes and was putting up to 60 percent of its bombs within 1,000 feet of the aiming point, almost four times better than in the dark days of 1943. Radar bombing, adopted from the British, was an alternative when conditions did not permit visual delivery, but it was not a precision technique.

B-17G Flying Fortress

Checklists

Checklists are “a list of items required, things to be done, or points to be considered, used as a reminder.” They are simple but powerful tools used by pilots, doctors, astronauts, construction workers, and the military to handle complex, non-routine problems. Checklists help people balance innovation and discipline, craft and protocol, and specialized talents within group collaboration. Michael Collins, one of the Apollo 11 crew members that went to the moon, referred to the astronauts’ ubiquitous checklists as “the fourth crew member.”

In 1935 at Wright Field in Ohio, the Army Air Corps hosted a fly-off between two long range bombers: the Douglas Aircraft Company’s B-18, a two-engine bomber, and the Boeing B-17, a four-engine, cutting edge aircraft with controllable pitch propellers, retractable landing gear, flaps, and an average speed of 232 miles per hour. During the fly-off, the B-17 crashed after take-off. Subsequently, the Army Air Corps selected Douglas for the contract to produce 200 B-18 bombers. During World War II the B-18 was used for training and anti-submarine actions.

Despite its crash, the Army Air Corps still wanted the B-17 and, after an investigation it was determined that the airplane crashed due to pilot error not the aircraft’s size or complexity. To avoid another accident, Air Corps personnel developed checklists the crew would follow for takeoff, flight, before landing, and after landing to minimize the opportunity for future human error. Up until this time, the checklist was used in aviation, but infrequently. It took the crash of the B-17, as well as the development of an extremely complex airplane, to institutionalize the use of checklists throughout the aviation world.

The crash of the B-17 was the catalyst for checklists to become commonplace in aviation. In addition to pilots, checklists are used today by doctors in operating rooms to reduce the risk of infection, construction workers to build complex buildings, and soldiers to make sure their vehicles operate correctly. Checklists take the pressure off people trying to remember all the necessary steps for complex systems, as well as freeing bandwidth to think about more challenging tasks.

Over the last nine decades checklists have been refined and improved. Boeing and Airbus both have departments dedicated to building checklists to support all their aircraft. The best checklists are only one page long and only hit the most important steps. They have opportunities where the group or team pauses and communicates. Finally, checklists fall into three categories: they help people and organizations do routine procedures better, prepare better, or problem-solve better.

I love checklists. I make a checklist every night for the things that I need to get done the next day. This helps keep me focused on the pursuit of my long-term goals.

Conclusion

Interested in doing an exciting workshop which uses real leadership case studies to improve your team’s self-awareness, leadership skills, and teamwork? Then bring your team to Savanah, Georgia and use TFCG’s Masters of the Air Leadership Workshop at the Mighty Eighth Air Force Museum. Or schedule a 3-hour workshop at your location or next off-site. Both options are a great opportunity to help you enhance your team’s skills. Hit the button below to learn more:

In the meantime, use your greater knowledge of the B-17 and checklists to enhance your understanding of Apple’s wonderful new show Masters of the Air.