One of the
United States' two standard heavy bombers until the introduction of the
B-29 Superfortress, the B-17 was flown by the United States Army Air Force
throughout the American participation in the Second World War. Wing to
wing with B-24 Liberators , B-17s were used by the US Eighth Air Force
based in the UK, to bombard German targets in Europe during daylight hours
a method which resulted initially in very heavy losses.
The Flying Fortress was designed for a competition, announced in 1934,
to find a modern replacement for the assorted Keystone biplane bombers
then in service. The prototype first flew on 28 July 1935, and went on
to win the competition. Boeing then built a few pre-production YlB-17s
(later re-designated B-17As), followed by 39 B-17Bs which entered service
in the late thirties. Money was short, and by the autumn of 1939 only
30 Flying Fortresses were fully operational. As the US was not then fighting
in Europe it did not seem to matter although, as it became clearer that
involvement was inevitable, orders were increased. Furthermore, a small
number of B-17Cs delivered to the RAF as Fortress Is quickly showed that
defensive armament was inadequate.
In September of 1941, a new Fortress appeared with an extensively modified
empennage. Gone was the pert fin and rudder riding precariously behind
the stabilizer. Instead, a broad yet graceful dorsal fin rose from amidships
and enveloped a deadly stinger of twin .50 cal. machine guns. A remote
controlled belly turret held two more. 50's. This was the B-17E, of which
112 were built. Four hundred more followed but with a manned Sperry ball
turret replacing the remote system. The B-17E was lengthened to 73 feet
10 inches to accommodate the new defensive tail position. Top speed was
317 mph, cruising at over 200 mph with 4,000 pounds of bombs.
The Pearl Harbor attack of 7 December 1941 finally brought the United
States into the war and production of the B-17 rapidly increased. By July
1942 the US began forming the Eighth Air Force in Britain, equipped with
B-17Es. The 'E' represented an important improvement over the earlier
B-17s, in that it had a tail turret, so eliminating a previous defensive
blind spot. On 17 August 1942 United States B-17s carried out a bombing
raid on the railway yards at Rouen in France. The real offensive, however,
started on 27 January 1943, when B-17s of the USAAF made their first attack
on Germany. Initially, casualties were very high because they attacked
during daylight hours to achieve greater accuracy and because proper formation
flying (to enable a group of airplanes to defend each other with cross-fire)
had not yet been formulated. Delivery of the B-17G (the major production
version) helped. The 'G' was the first variant to have a gun turret under
the nose, so increasing the armament to 13 guns.
Production of the similar B-17F was undertaken by Douglas and Vega, a
subsidiary of the Lockheed Aircraft Corp., was taking its toll in speed.
The B-17F, though now armed with eleven.50 cal. guns, could only reach
299 mph, but landing speed was up to 90 mph! Service ceiling was 37,500
feet and range 2,880 miles. It took twenty-five and a half minutes to
climb to 20,000 feet. Three thousand, four hundred B-17F's were produced
by the three companies.
By September, 1943, the Flying Fortress showed its final shape. During
firepower tests on the XB-40, a modified B-17F, the advantage of a chin
turret was clearly proven and a new series, labeled B-17G, sported this
nasal appendage. The Bendix turret held two .50 cal. guns and this model
had a total of twelve of these weapons with 6,380 rounds of ammunition.
In all, there were 8,680 B-17G's built by Boeing, Vega, and Douglas to
make this the largest production variation. Following the first Model
299, the Air Corps purchased 12,725 B-17 type aircraft.
On 19 July 1943 US B-17s and B-24 Liberators carried out the first bombing
raid on Rome; and US bombing in Europe reached its high point in February
1945 with a 1000-bomber raid on Berlin, escorted by 400 fighters, and
the Dresden raid (alongside the Royal Air Force) which caused a massive
fire storm to sweep the city.
Meanwhile, B-17s were also helping to win the war against Japan, although
by mid-1943 the larger B-29 had begun to take over the major strategic
bombing missions. By the end of production, more than 12700 B-17s had
been built, of which a few served with Royal Air Force Coastal Command
and the United States Navy for patrol, air-sea rescue, anti-submarine
and other duties.
B-17G specifications included a span of 103 feet 9 inches, length of 74
feet 4 inches, and a height of 19 feet 1 inch. The four supercharged Wright
R-1820-97 Cyclones delivered 1,200 hp and gave a top speed of 287 mph,
cruising at 182 mph. Service ceiling was 35,600 feet, with a range of
3,400 miles. Empty and gross weights were 36,135 pounds and 55,000 pounds.
Maximum fuel load was 3,630 gallons.
Cargo conversions of the B-17 were known as C-108.
First American Missions From England
air power made its European debut during the summer of 1942. On June 12,
Colonel Harry Halverson led thirteen B-24 Liberators on a first daring,
long-distance raid against the oil refineries at Ploesti, Rumania. Taking
off from Egypt, 1,000 miles from the target, the bombers surprised the
enemy. All the planes got safely away, though one B-24 crash landed later.
The first American mission from England took place, appropriately, on
the Fourth of July. Six air crews, flying A-20 Boston bombers borrowed
from the RAF, joined six British crews on a low-level raid against air
bases in Holland. The Germans were warned by radio from a picket ship
off the Dutch coast, and two of the bombers flown by Americans were shot
down. The bombardiers of two of the other planes were so confused by the
camouflaged targets that they failed to drop their bombs at all.
More auspicious was a raid on August 17, against the railroad yards at
Rouen. A dozen B-17 Flying Fortresses loaded with three hundred-pound
bombs, completed their mission without losses. In the fall, the North
African invasion diverted planes and men and temporarily stalled the build-up
of U.S. air strength in England. But as the Eighth continued to stab at
the enemy, American crews matched the courage and ability of veterans.
On one occasion, for instance, nine B-17's, turning back from a canceled
mission against Rotterdam, were jumped by more than twenty German fighters.
The Americans fought their way back to England, but in one bomber the
pilot was injured and the copilot killed. The bombardier, who had been
washed out of flying school, took over the controls and flew the plane
back home on two engines