Since World War I, the tremendous destructive power of the submarine has been
demonstrated time after time. In the First World War, German U-boats created
problems for North Atlantic shipping, moving men and supplies to Europe from
North America. During the early years of WWII, the U-boat wolf packs nearly
cut off Britain’s convoy lifeline from the United States and Canada, sinking
a staggering amount of tonnage. In 1940 alone, U-boats sank 520 ships, with sometimes as many as 60 vessels going down in one month.
Almost any aircraft available, suitable or not,
was pressed into ASW service on both sides of the Atlantic. From private and
Civil Air Patrol planes to Coast Guard Grumman Widgeons, to blimps, to big
B-24 Liberators, nearly anything
that could fly was put to use patrolling the Caribbean and Atlantic waters
off America. Of the aircraft that were rushed into early anti-submarine
patrol duties, the most successful was the already obsolete
Catalina. The “Cat” flying boat possessed good range, capacity and
durability and was used by most of the Allied forces throughout the War.
Its versatility allowed it to be used not only for ASW, but patrol, search
and rescue, anti-shipping, and many other useful wartime roles.
Several other existing aircraft were adapted to the ASW role and were quite
successful. The twin-engine Martin PBM Mariner flying boats, much larger than the PBY Catalinas, filled an
important need during the second World War and were used for many years following
the end of the war. The follow-on aircraft to the PBM Mariner was the Martin
P5M Marlin which was designed to hunt the large USSR submarine fleet. It
turned out to be the last flying boat in the U.S. Navy inventory and the
last production aircraft built by Martin.
Possibly the best all-round sub hunter aircraft of the
war was the Consolidated B-24 Liberator. A version of the Navy Liberator was modified for Naval ASW
use was built in large numbers and was called the PB4Y-1 Liberator. It
later evolved into the
PB4Y-2 Privateer, which also flew on for many years and was used in both
Korea and Vietnam as well as an electronic countermeasures platform during
the Cold War.
The development of specialized aircraft to counter the
U-boat threat began during World War II with Lockheed’s PV-1 Ventura proving
to be fairly successful at the task of a shore-based patrol bomber. The
Ventura was based on the Lockheed Hudson bomber (already used extensively
for anti-submarine duty by U.S. and British forces), which was derived from
a pre-war civilian transport called the Lockheed 14.
The improved follow-on to the Ventura was the PV-2 Harpoon with better
handling and increased range and payload.
While land-based aircraft could provide cover for the convoys near land and
a certain distance out to sea, a gap remained in the mid Atlantic where
coverage was not possible due to their limited range. The solution came in
the form of the Escort Carrier or Baby Flat top armed with Grumman TBM/TBF
Avenger torpedo bombers and F4F/FM Wildcat fighters. Once a contact was made
and hunted down, the Wildcats would strafe and neutralize the submarine’s
anti-aircraft so the Avengers could make their attack runs using depth
charges, rockets, and/or torpedoes. The carrier group’s destroyer escorts often would come in to finish the
job and pick up any survivors. The USS Bogue was the first escort carrier to be
used in the Atlantic for anti-submarine warfare, and her group sunk seven
U-boats on their first cruise proving the concept. All together, the escort carriers were
responsible for destroying or capturing 56 U-boats and effectively closed
the mid-Atlantic gap to German submarine operations.
Near the end of WWII, the U.S. Navy’s requirement for a more powerful,
longer range, shore-based ASW
patrol aircraft was filled by the Lockheed P2V
(P-2) Neptune. The Neptune was the first aircraft to be designed from the
ground up specifically as a Naval anti-submarine patrol bomber platform.
Completed too late to see any action
during the War, the Neptunes served for
several decades during the Cold War patrolling the oceans and keeping track
of the numerous Soviet Union submarines all the way into the late 1970s.
carrier-based aircraft and tactics for the ASW role were also
developed. Early on, pairs of aircraft were used in a Hunter-Killer tandem –
one carried the search radar while the other carried weapons. First Grumman TBM Avenger torpedo bombers were adapted to the role and then Grumman AF-2
Guardians were used. The Hunter-Killer functions were both
combined into one airframe in the early 1950s as the Grumman S2F (S-2)
Trackers, or “STOOFs” as they were nicknamed, also served
well into the 1970s and, along with the P-2 Neptunes, were among the last of
the piston-engine aircraft in the United States Navy inventory.
The replacement for the land-based P2V Neptune came in
the early 1960s in the form of the Lockheed P3V-1 or P-3 Orion. The
P-3 was adapted from the Lockheed L188 Electra airliner and was in
production for over 30 years. It provided the Navy with a large increase in
capacity, payload, and performance over the old P-2. Even with the end of
the cold war and the reduced submarine threat, the P-3 Orion is still in
service today and is being flown by many different countries
around the world, including the
United States. The tough, versatile P-3 airframe has been modified into
other configurations as well, such as an electronic surveillance platform
(EP-3A Aries), as a hurricane hunter, and even as a fire bomber to name a
In the early 1970s,
Lockheed began producing the jet-powered replacement for the piston-engine
Grumman Tracker, the more capable
carrier-based plane nicknamed the “Hoover,” but officially known as the S-3 Viking. Stuffed with electronic gear and
sensors, the four-man-crew Viking is an extremely capable submarine hunter.
With the diminishing requirement
for ASW work, Vikings have also been
modified for use as aerial tankers and electronic warfare aircraft and have
been upgraded to carry other weapons such as the Harpoon for anti-surface
ship warfare as well.
The 40-year-old P-3C Orions and 30-year-old S-3B
Vikings, along with various other ship and carrier-based Anti-submarine
helicopters, are still used to defend the United States Naval fleet from
submerged as well as surface threats and patrol the world’s oceans today.