The Boeing B-17 Flying Fortress

The Boeing B-17 Flying Fortress

Few aircraft can claim the pivotal role in US victory during World War II that the Boeing B-17 Flying Fortress can.

Designed to meet the August 16, 1934 Army Air Corps requirement for a multi-engined anti-shipping bomber to replace the twin-engined Martin B-10 with a 1,020-mile range, a 2,000-pound bomb load capability, and a 200-mph speed, the B-17 had broken from the standard twin-engined design by offering twice the number of powerplants in order to significantly increase payload, range, and service ceiling. The resultant Model 299 prototype, powered by four 750-hp Pratt and Whitney Hornet, three-bladed pistons, first flew on July 28, 1935, and could carry a payload of eight 600-lb bombs. It was both the largest US land plane and the world's fastest bomber at the time. Thirteen pre-series aircraft were delivered between December 2, 1936 and August 5, 1937.

So inherently flexible had the basic low-wing, dorsal-finned aircraft been, however, that it had been progressively adapted for varying roles with turbocharged Wright Cyclone engines for higher-altitude performance, an increased area rudder and flaps for greater effectiveness on the B-17B, and self-sealing tanks, flush guns, and a ventral bathtub on the B-17C, which had first appeared in 1939 and had been operated by the RAF in England. The B-17D weathered most of the flak in the Pacific Theatre. The succeeding B-17E, appearing in 1941, incorporated a redesigned aft fuselage for greater flying stability at high altitude with a larger fin, increased armor protection, and ventral and tail turrets. The first of these, which demonstrated 317-mph speeds, entered service in the Pacific Theatre at the beginning of 1942 and 512 had ultimately been built. The B-17F, which also appeared that year, featured the newly introduced long Plexiglas nose, paddle-wing propellers, an underwing rack provision, and even more powerful armament, and resulted in a 3,405-production run. The B-17G, the ultimate and most numerically popular version, featured a chin turret, flush staggered waist guns, and a 17,600-pound bomb load capability, and was intended for European deployment. Its sheer design capability, which had been far more ambitious than any previous version, permitted a sufficient bomb and fuel load to be carried without retarding range and accounted for an additional 8,685-unit production. Both the B-17F and -G can be credited with the decimation of Germany.

So instrumental had the design been to the war, in fact, that Boeing, Lockheed, and Douglas had all simultaneously churned out copies in staggering numbers, eventually totaling 12,731 airframes.

A recent B-17 flight, in which I myself had "returned to World War II skies," had occurred from Farmingdale's Republic Airport in Long Island, New York.

The aircraft, with production serial number 44-83575, had been built under contract from Boeing by the Douglas Aircraft Company in Long Beach, California, and had been accepted on April 7, 1945. Too late for combat, the airframe had served as part of the Air/Sea 1st Rescue Squadron and the Military Air Transport Command. Seven years later, in April of 1952, it had been used to test the effects of three nuclear explosions and had finally been sold as part of an 800-ton scrap pile after a 13-year cool-down period.

Fighting the fierce slipstream from the still-turning propellers, the six passengers climbed through the aft, starboard hatch that September morning and clamored through the aircraft's interior toward one of the nine, seatbelt-equipped floor seats. A throttle advancement, translating into a deeper engine vibration, signaled brake release and preceded the short taxi to Runway 19's threshold, as the electrical-mechanical system, sending a screech through the interior, channeled its effects through the aircraft's arteries and actuated the fabric-covered trailing edge flaps into their take off positions. The tail, torquing at right angles to the ground, responded to periodic brake applications as its singular wheel rode the end of its shock absorber. Full throttle advancement, flooding the cabin with vibration, initiated the B-17's take off roll, sending an overwhelming slipstream of air over the horizontal stabilizers which responded with incessant up- and down-flutter in its wake. At 30 mph, the vertical tail became fully effective, permitting the nose to be aligned with the runway centerline. The empennage, now a flying, though not-independent "airplane" itself, gently rose from the concrete, as the Flying Fortress, in a momentary, horizontal position on its pitch axis, generated sufficient lift and surrendered itself to flight with its thick, straight, massive wings at 90 mph and forwardly retracted its singular-wheeled bicycle undercarriage into the inboard engine wheel wells. The maneuver had preceded every single World War II victory.

Climbing at 600 fpm, the Flying Fortress penetrated the early-morning blue barely marred by a few cloud wisps on a due-south, 180-degree heading and maintained 135 mph. Throttled back as it reached the lilly pad-green patches forming a mosaic off of Long Island's South Shore, the aircraft leveled off at 1,000 feet and commenced a left bank with the aid of its mechanically-linked ailerons toward the Capetree Bridge leading to Jones Beach and its signature monument.

Supporting its weight with its thick, wide-chord wings, the bomber cruised over the pale-blue and silver reflecting surface of the Atlantic, straddling the coast and sending an intense vibration through its cowling as its Wright Cyclone engines turned their Hamilton Standard propellers at 1,800 rpm.

The massive bomber''s stabilizing cruise mood had prompted closer internal inspection of the cabin.

Designed as a high-altitude strategic bomber, the B-17 incorporated several gunner stations. The Plexiglas nose provided a 180-degree, unobstructed forward view, below which was the chin turret, and this section was occupied both by the bombardier and the navigator, whose side-facing station was on the port side. Behind and above was the two-person cockpit which provided vision through its two forward windows. The top turret, behind and a step below the flight deck, provided the only 360-degree view of the sky, and its gunman doubled as the engineer. Take off and landing provision had been provided by the two aft-facing, seatbelt-equipped floor seats. A very narrow, single-foot-wide catwalk led through the bomb bay, whose under-fuselage clamshell doors remained closed in flight, to the radio operator's station, which featured the radio operator's console itself, two tiny fuselage windows overlooking the wing, and another two aft-facing floor seats. The aircraft's main section housed the ball turret, the waist gunners' stations, the considerably-sized windows, and five inward-facing floor seats. Visible in its aft portion was the shock absorber rod leading to the tail wheel. The tail gunner's station was located in the extreme aft portion of the fuselage. The interior sported entirely exposed dark green ribs and metal skin panels, with the aircraft having been designed for functionality, not comfort.

The B-17G operating today's flight continued to straddle Long Island's South Shore, alternating course by 180 degrees to a fly westerly heading before retracing its steps in the opposite compass direction.

The cockpit sported the two control yokes and the central pedestal with the throttle, mixture controls, and prop pitch handles. A chart recommended ratios of engine rpms to mixture settings.

A right bank turned the Flying Fortress to a 010-degree heading, at which time a throttle reduction gravity-induced the airframe down to 600 feet for a characteristic fly-over of Republic Airport's Runway One, in the opposite direction to which it had taken off, at 145 mph. Even at this height, the quad-engined bomber must have appeared colossal in comparison to the single-engined Pipers and Cessnas which normally plied its skies.

Passing over the airport's perimeter, the B-17 turned to a due-east, 090-degree heading before arcing 100-degrees to the right in order to configure itself for its final approach to Runway 19. All too soon had its six passengers been instructed to take their floor seats and refasten their seatbelts in the various sections. Lift lost due to progressive power reductions was initially augmented by trailing edge flap extensions, only to be ultimately counteracted by drag-induced undercarriage deployment, as evidenced by the high shrill actuators piercing the interior like knives. Passing over the runway's threshold at a nose-down pitch, the pale green bomber first snatched concrete with its port wheel "paw" before the physics forces of weight transfer caused the starboard wheel to mimic the action, and the runway surface friction depleted its ground speed sufficiently to remove the empennage from aerodynamic flight and place it in trailing mode as a slight screech indicated the groundward settling of its tail wheel.

Marshaled into its parking position only feet from a B-24's high-wingtip, the B-17 rotated 180 degrees to the right on its tail wheel and starved its mighty Wright Cyclone engines of fuel, diminishing their propellers' rotations to stationary silences in the very warm, still-summer air beneath flawlessly-blue skies.

Climbing through the aft hatch, I stepped on to the ramp. Because of the Flying Fortress's performance capabilities and ruggedness of design, post-World War II skies had been assured of remaining blue ones...