Case Studies in the Achievement of Air Superiority - Air Force ...

KOREA
some were likely to seep through or circumvent even the most vigilan
fighter sweep. The numbers problem had just not been severe in 1944-45 in
Europe once the Allies gained bases in France. Korea was a different situation,
and different tactics were required.
The different tactics called for were not really new, but it was difficult
to apply them to the B-29. Fifth Air Force had first used SHORAN techniques
successfully in February 1951, with its B-26 night-attack light
bombers. FEAF B-29s began using SHORAN equipment in April,
against built-up areas and railroad yards. SHORAN used ground-based
radio transmitters (or beacons), accurate maps, and radio receivers in
the B-29s to place the bombers over a target. Specially placed radio
stations would transmit signals the intensity of which was a function of
range. The signals of the stations overlapped, and the B-29s carried a
receiver that would respond when an aircraft, navigating along the arc
of one beacon, flew across the point where that beacon’s signal intersected
a second beacon’s signal with a particular intensity. Given a
sufficient number of beacons, there would be such a point of intersection
above every main target.
SHORAN bombing accuracy depended upon several factors. For example,
SHORAN transmitting signals dropped off in power with range, and
the B-29s often flew at the limit of the SHORAN signal arcs. This meant
that the bombers might be off their planned course by several hundred feet.
Errors were also introduced because of mistakes in maps. In theory, the
SHORAN computation personnel knew the distance of the target from the
beacons and could calculate the proper level of signal that would carry the
bomber over the target. They would then give that information to the B-29
navigators. Sometimes, however, the data on distances were not accurate
enough. Even small errors could throw the bombs dropped by high-level
bombers off target by several hundred feet. As a result, it was estimated
that no more than half of the bombs dropped during SHORAN missions in
September 1951 were within 500 feet of their intended targets.66 There was
another problem: bombing aircraft using SHORAN had to approach the
target along one of several arcs; the defenders of airfields, which were
repeatedly attacked, would soon calculate the SHORAN arcs and position
searchlights, antiaircraft (AA) guns, and MiG interceptors a~cordingly.~~
SHORAN signals could also be jammed. The British had successfully
jammed a SHORAN-like system used by the Luftwaffe in 1940, and the
Chinese did attempt to jam or confuse the short-range bombing radars carried
by B-29s, but FEAF SHORAN operations continued without serious
electronic interference until the end of the war.68
The switch to night bombing actually began in April 1951, but the real
jump in the frequency of such attacks took place in November and Decernber
1951 and in the early months of 1952. (See Table 9-5) After October
1951, there were really two air superiority campaigns-one fought above
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