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Beyond The Horizon
AUTHOR LCDR. Glen F. Erickson, USN
CSC 1989
                      Executive Summary
Title.  Beyond the Horizon
Thesis.  The LCAC will preserve the significant military
capability of Amphibious assaults but not without its
Issue.  Since World War II, the Navy-Marine Corps team has
not significantly altered its method of beach assault or the
landing vehicles used for the assault.  Landing craft are
deployed form amphibious ships at three to five miles
offshore and then proceeded to the beach at 8 knots.
Unfortunately the enemy will no longer allow the United
States the luxury of preparing the beach for several days
prior to an amphibious assault.  Modern radars will eliminate
the chances for surprise and modern weapon systems will
require amphibious shipping to remain a healthy distance from
the beach.  The Landing Craft Air Cushion (LCAC) will change
the way of landing Marines on hostile shores by introducing
the capability to launch from over-the-horizon.  The LCAC's
speed and range offer significant capabilities over the
current LCM-8 landing craft.  However, the LCAC's size, high
technology, and design features present some drawbacks.
Additionally, use of the Amphibious Assault Vehicles (AAV) in
an over-the-horizon amphibious operation is not practicle.
Conclusion.  Continued evaluation and improvements in
amphibious assault doctrine and equipment are necessary, in
order to keep up with the technological improvements in
combat systems.
                      Beyond the Horizon
Thesis Statement: The introduction of the Landing Craft Air
Cushion (LCAC) serves to preserve the significant military
capability of amphibious assaults but not without its
I.  Introduction
    A. Definition of amphibious operation
    B. Amphibious assault concept
    C. Past method of assault
    D. Introduction of LCAC
II. LCAC characteristics and capabilities
    A. Characteristics
    B. Capabilities
         1. Over-the-horizon assault
         2. Tactical operational capabilities
         3. Anti-mine capabilities
         4. Communications
         5. Navigation
III. LCAC operations in the over-the-horizon assault
    A. Advance force operations
    B. Naval gunfire
IV.  LCAC drawbacks
    A. Design characteristics
         1. LCAC size compared to LCM-8
         2. New technology
    B. AAVs compatibility with LCAC
    C. New equipment costs
V.  Conclusion
                     Beyond The Horizon
     The joint service publication, Doctrine For Amphibious
Operations, defines an amphibious operation as  "
attack launched from the sea by naval and landing forces
embarked in ships or craft involving a landing on a hostile
shore."1  Perhaps the most famous and best remembered
amphibious operations were conducted during World War II
and the Korean War.  These operations were critical to the
United States and its allies to introduce forces on a
hostile shores and proved to be turning points in the
wars.  More recently, amphibious operations by the United
States in Grenada and by the British in the Falkland
Islands War, once again revealed the value of amphibious
     A successful amphibious assault relies on many
factors.  Surprising the enemy is probably the most
important.  For example, General Eisenhower realized its
importance during World War II, when he went to great
lengths to ensure the Normandy invasion was kept secret
from the enemy.  Another important aspect is control of the
Area of Action (AOA).  The chances of success are greatly
increased when the Commander of the Amphibious Task Force
(CATF) has control of surface and subsurface, in addition
to air superiority.  Without control of the AOA, assault
echelon shipping is subject to attack even before the
landing force is disembarked.  Additionally, an amphibious
landing should be located where enemy forces are not.
Amphibious assaults are complicated and success relies on
detailed planning and realistic rehearsals.
     Since World War II, the Navy-Marine Corps team has not
significantly altered its method of beach assault or the
landing vehicles used for the assault.  World War II
assault forces typically spent days clearing underwater
obstacles and preparing the beach with naval gunfire.
Landing craft were deployed from amphibious ships at three
to five miles offshore and then proceeded to the beach at 8
knots.  The Navy-Marine Corps team still practices this
method of beach assault.  Part of the reason for the lack
of change in amphibious operations stems from post war
thinking.  After both World War II and the Korean War,
military leadership predicted that the introduction of
forces using amphibious assault would become outdated and
not practical in future conflicts.  Prior to the Falkland
Islands War, the British had intensions of greatly
decreasing their amphibious capability.  They too thought
amphibious warfare had no place in today's high
technological world.  Their experience at the Falkland
Islands turned that thinking around.  Modern enemy
capabilities  complicate the traditional amphibious assault
and greatly increase the risk of failure.   Amphibious
warfare is not outdated, however, much of our equipment and
doctrine need updating.
     Our amphibious warfare capabilities can no longer be
neglected.  The enemy will not afford us the luxury of
preparing the beach for an amphibious assault several days
in advance.  Modern surveillance radars will practically
eliminate the chances for a surprise landing on a hostile
shore.  With the mobility of modern weapon systems, the
enemy can prepare defensive positions (to include missile
systems), in a matter of hours.  Amphibious shipping
closing the beach to a distance of three to five miles will
be in danger of missile attack.  This quickly became clear
to the British during the Falkland Islands War when an
Exocet missile on a trailer at Port Stanley damaged the
British destroyer Glamorgan.  One solution to update our
amphibious assault equipment has been the introduction of
the high speed and extremely mobile Landing Craft Air
Cushion (LCAC).  The LCAC will preserve the significant
military capability of amphibious assaults but not without
       LCAC will lead Amphibious warfare into the
twenty-first century.  Its versatility and speed will
permit the Navy-Marine Corps team to rewrite amphibious
doctrine to account for technological changes in weapon
systems, communication equipment, and surveillance
systems.  Additionally, it will include the concept of
over-the-horizon amphibious assaults.  As early as 1975,
the Marine Corps has been investigating air cushion
vehicles as an innovative method of landing forces on the
beach.  "The increased speed and mobility of
hovercraft should make them less vulnerable than
conventional craft.  More importantly their speed would
disperse the enemy defense making him more vulnerable to
counterattack."2  This was the Commandant of the Marine
Corps thoughts in 1975.  This type of thinking has lead to
two operational Assault Craft Units (twelve total LCAC),
and the production program calls for a total of ninety
craft by the year 1995.
     The Marines have long understood the value of the
helicopter and its ability to quickly transport personnel
and equipment to a landing site during an amphibious
assault.  The LCAC's speed and mobility is a valuable
addition to the landing force during an assault.  "Finally
we will have a landing craft that truly complements the
helicopter in speed, tactical surprise and the ability to
attain a rapid buildup of Marine combat power ashore
without exposing our amphibious ships to enemy fire.
Coordinating helicopters with the LCAC's speed and
amphibious capability, assault forces will be able to
quickly move Marines and equipment to inland
     The LCAC is a new form of landing craft that employs
air cushion technology.  Gas turbine engines drive four
centrifugal fans to supply an air cushion for the craft.  A
flexible skirt around the edge of the craft contains the
air.  Gas turbine driven propellers are used for
propulsion.  The hovercraft operates about four feet from
the water's surface, when on cushion.  The LCAC is made
almost entirely of aluminum and measures 88 feet long, 47
feet wide, and 23 feet high when on cushion.  It has
forward and aft ramps for easy loading and unloading of its
60 ton maximum payload.  Notional loads for the LCAC are
listed in Appendix A.
     A significant capability of the LCAC over the
conventional landing craft is its speed.  Because the LCAC
rides on a cushion of air over the water, it has the
capability to achieve speeds in excess of 40 knots with a
full load.  This is a considerable difference from the
conventional crafts maximum of eight knots.  While
conventional amphibious craft must be launched from three
to five miles from the beach, assault shipping can launch
the LCAC at distances of anywhere from a couple thousand
yards to a hundred miles from the beach.  Unlike the
launching of conventional landing craft, amphibious ships
do not have to ballast down to launch the LCAC.  They can
be launched from a dry well allowing the ship maximum
     The LCAC's speed and 150 mile range, allows assault
shipping to remain over-the-horizon when deploying the LCAC
and therefore significantly increasing their chances for
survival.  By launching the amphibious assault from
over-the-horizon, amphibious shipping can remain integrated
in the carrier task force layered defense.  The importance
of this cannot be overstated.  Amphibious ships have weak
anti-air defenses and no defense against submarine attack.
With the over-the-horizon assault concept, the amphibious
task force (ATF) will no longer be subject to certain
failure prior to off loading the landing force.  Combat air
patrol (CAP) and carrier task force missile ships will
protect the ATF from enemy aircraft and anti-ship cruise
missiles.  The anti-submarine warfare ships will screen the
ATF from submarine attack.  Lastly, by remaining
over-the-horizon, the ATF ships minimizes their chances of
encountering mine fields.
     When deployed from 25 to 50 miles offshore, assault
forces can proceed into the beach in any number of
directions.  With its 200 mile range and high speed, the
LCAC operator can try to deceive the enemy by fainting to
one direction and then quickly changing directions toward
the landing beach.  Because the enemy cannot be certain of
where the LCACs and helicopters will land, they will not
know where to concentrate their forces.  This requires the
enemy to either spread out and weaken his defenses or wait
for the assault forces to land.  The over-the-horizon
assault will keep the enemy off-balance and forced to
assume a position of responding, instead of directing the
     Next to the increased speed, the second greatest
tactical advantage of the LCAC over conventional landing
craft is the increase number of beaches to where it can
travel.  The LCAC is not limited by reefs, bottom
gradients, swamps, tides, or current.  It can assault
beaches that are physically impossible for conventional
craft.  The LCAC is able to assault 73 percent of the
worlds beaches vice only 17 percent available to
conventional landing craft.  Alone, this figure is subject
to challenge but it is fairly safe to say that the
percentage is much higher for the LCAC.
     The LCAC is more immune to adverse weather conditions
than conventional landing craft.  "Because of its
self-fendering and ability to operate from a dry well, an
LCAC can launch in sea states that would preclude LCU/LCM
operations. "4  " Landings in higher sea states will be
possible since the LCAC is less vulnerable to high seas and
surf than present day landing craft. "5  Although sea
state effects the maximum speed of the craft, the LCAC
still maintains a significant speed advantage over
conventional craft.  In a sea state condition four, the
LCAC is still capable of 25 knots.  One major advantage of
the LCAC in rough surf is its ability to transit the surf
and offload on dry land.  During World War II, a
significant amount of equipment and lives were lost when
LCMs lowered their front ramp in rough surf conditions.
     A major obstacle for conventional landing craft is
underwater mine fields.  "LCAC has a smaller signature for
mine activation, while not producing any pressure
signature, and thus substantially reduces or eliminates the
mine threat. "6  The Soviets have an excellent mine laying
capability.  Even under short notice conditions, they can
lay a mine field using indirect fire artillery or
aircraft.  This capability would be fatal to conventional
craft.  Although the LCAC is susceptible to land mines,
LCACs have a better chance of survival against underwater
mine fields.  When above hump speed, 21 knots, the LCAC
presents no pressure or magnetic signature and the air
spray under the craft reduces its acoustic signature.  This
is a significant advantage over conventional landing
     Although the LCAC is a large, noisy, undefended
target, the LCAC's survivability from launch to beach
landing is greater than conventional craft.  In addition to
its mine field survivability, the LCAC's speed and
maneuverability make them virtually immune to indirect
fire.  Also "the LCAC IR signature is quite low when
waterborne due to the masking by spray."7  Because the
LCAC travels above the water, it is oblivious to torpedo
attack by ships or submarines.  With two propulsion units,
one side of the LCAC can be damaged and the craft will
still be operational and "...tests have shown that it
(LCAC) can sustain considerable damage and continue to
operate. "8  These factors greatly increase chances for a
successful amphibious assault.
     The compactness of shipping in the current amphibious
assault doctrine allows the Commander Amphibious Task Force
(CATF) to observe the entire assault and to easily
communicate with participants when adjustments are
required.  Even though communications are easier when all
the participants are within the line of sight, this
compactness is one of the main reasons for doctrine
change.  One enemy weapon system could take out any ship or
all ships, not to mention the catastrophic results a
chemical or nuclear bomb would have.  Additionally, this
compactness will be of less benefit if the enemy is jamming
radio circuits.  The LCAC has one HF, one VHF, and one UHF
radio installed onboard, however, it has no secure voice
capabilities.  With such an unsophisticated communications
suite, the over-the-horizon assaults will rely on
decentralized control of the landing craft, thereby giving
the landing craft commander more options for success.
     The LCAC's onboard navigation equipment is not
sophisticated enough to accomplish a pin point landing from
over-the-horizon.  Its navigation radar, the LN66, is a
short range radar (given the LCAC height of 23 feet).  When
launched from over-the-horizon, the craftmaster will rely
on either his gyrocompass or backup magnetic compass for
his initial course.  This will make any kind of zig zag
plan prior to landing difficult.  When he is closer to
land, he can begin plotting his position.  Night operations
will be more difficult because the craftmaster will not be
able to see prominent landmarks to aid in navigation.  The
LCAC does not need a better radar, because undoubtably all
assaults will be conducted in an emission controlled
(EMCON) environment, to ensure tacticle surprise over the
     Over-the-horizon amphibious assaults will completely
eliminate naval gunfire in support of the amphibious
assault.  All United States Navy ships, with the exception
of the battleships, have gunfire ranges of less than 15
miles (Appendix B).  "Because of the inability of naval
gunfire ships to support the initial assault, greater
reliance must be placed on close air and attack helicopter
support. "9  Additionally, a greater urgency will be
placed on landing artillery earlier.  Although the lack of
naval gunfire would be of great concern in past amphibious
landings, one of the primary ideas behind the
over-the-horizon amphibious assaults is to expand the
enemy's battlefield and to land forces on undefended
beaches.  During the over-the-horizon assault, helicopters
and the LCAC will be launched to quickly transport marines
and equipment to undefended beaches, therefore, eliminating
the requirement for naval gunfire support prior to the
     Advance force operations can be greatly reduced when
employing LCACs.  They are not hindered by underwater
obstacles so the need for Navy Seals to clear underwater
objects and to conduct hydrographic surveys are no longer
required.  These operations have always been covert and
their success was critical to a successful assault.
Without advance force operations, the chances of surprise
are increased.  Intelligence gathering will be the most
important advance force operation in an over-the-horizon
operation.  We must locate the enemy's position so assault
forces can land where the enemy is not.
     The LCAC has some drawbacks that should be noted.  The
mere size of the LCAC has a great impact on the number that
can be loaded into amphibious assault shipping.  Although
the LCAC has roughly the same cargo capacity as the LCM-8,
the landing craft that it will replace, the LCAC is more
than twice the size of an LCM-8.  As a result amphibious
ships in the Navy's inventory can hold two to three times
more LCM-8 craft than LCAC.  A new ship class, LSD-41, has
been constructed specifically to transport the LCAC.  The
LCAC will compensate for its difference in size by making
multiple high speed runs to the beach.  When launched from
20 miles offshore"... there will be an hour and a half
between the time an LCAC makes its initial landing and
returns with a second load. "10
     "LCACs are high-tech craft which require
sophisticated, high tech maintenance and support. "11
There are potential growth problems as LCACs begin to
deploy with amphibious ships.  The LCAC requires 23
different personnel specialties for support.  Although some
of these support functions can be performed by the crew of
the amphibious ship, several of these specialties are
normally not assigned to amphibious ships.  Of the ones
that are, some of these personnel are not familiar enough
with the LCAC to fill them.  Therefore, additional
personnel will embark with the LCACs to operate and
maintain them.  "LCAC detachments embarked on amphibious
ships may occupy some spaces otherwise available to the
landing forces. "12  Additionally, LCAC maintenance
personnel will bring their own tools and repair parts, much
the same as helicopter detachments do.  "Embarkation plans
must fully consider berthing and stowage losses due to LCAC
assignments. "13
     The question concerning the amphibious assault
vehicle's (AAV) role in an amphibious assault when using
LCACs has not been answered.  The AAV is the primary
personnel carrier in an amphibious assault and the primary
means of mobility once ashore.  This "... important piece
of the amphibious system still has not kept up with the
advanced shore capability provided by the helicopter and
the LCAC. "14  The LCAC was not designed to be a personnel
carrier.  Its noise, considerable spray, and danger of
foreign objects and debrie (FOD) through the large
propulsion systems, limit personnel to the small control
booth or inside equipment on deck such as a tank or Light
Armored Vehicle (LAV).
     The LCAC has the ability to carry AAVs (two each).
However, this would result in numerous additional round
trips to the beach for delivery.  An LCAC carrying AAVs
must continue all the way to the beach.  They cannot
offload AAVs while still waterborne.  The LCAC's ramps will
not support the weight of an AAV unless the end of the ramp
is supported by land.  If we are going to shuffle AAVs to
the beach in this fashion, the requirement for the assault
vehicle to be amphibious is no longer valid.  The AAV will
be the weak link in the amphibious assault.  Unless another
vehicle is designed, the concept of over-the-horizon
amphibious assault for anything other than a small raid
force is not possible.
    Improvements and new systems cost substantial amounts of
money.  In a period of decreased military spending, it will
be difficult to purchase the equipment required to keep our
amphibious assault forces updated.  The Mv-22 Osprey, with
its  significant improved capability over the helicopter to
land marines, is quite close to being cancelled.  The LCAC
requires new shipping to transport it to the Area of
Action.  All this  new equipment means more money, money
that probably will not be available to design a new AAV or
a vehicle to quickly transport AAVs close to the beach.
     The LCAC is an amphibious assault vehicle that can
keep the enemy off-balance.  With this asset many
innovative methods of amphibious assault can be developed,
instead of continuing with World War II tactics.  It
provides an over-the-horizon capability thereby keeping
ships away from the beach and at the same time concealing
the identity of the landing sites.  Due to the LCACs
ability to land on approximately 73 percent of the world's
beaches, the Navy-Marine Corps team can avoid the enemy
defenses and achieve the element of surprise on a hostile
shore, ensuring a successful amphibious assault.
     The amphibious assault is still a viable means of
introducing friendly forces onto hostile territory.  The
United States and its allies can no longer endanger the
lives of personnel on amphibious shipping by practicing
World War II style amphibious assaults.  Although the
conventional method may again be useful in special
circumstances, advances in gunnery and missile systems are
making it more impractical.  The LCAC along with the
helicopter will play an important role in future amphibious
landings.  However, in order to keep up with the
technological improvements in combat systems, continued
evaluation and improvements in amphibious equipmemt and
doctrine are necessary.
  1MCDEC,USMC, Marine Division, FMFM 6-1 (Quantico,
1978) ,p.39.
  2LtCol Alvin Doublet, "The Air Cushion Vehicle and Its
Future Applicable to National Defense," dtd April 1986
(Maxwell AFB, Alabama).p.87.
  3Joc W.D. Christensen, Jr., "LCAC Ushers in New
Amphibious Era From Over the Horizon," Surface Warfare
(Mar/Apr 1984) ,p.9.
  4Col Marshall Darling, "LCACs: Characteristics and
Tactical Improvements," Marine Corps Gazette (December
1984) ,p.43.
  7MCDEC,USMC, TACMEM0 PZ 005070-1-85, OH 7-15 (Quantico,
1985) ,p.3-3.
  8Maj Thomas Bailey, "Over-the-Horizon Assault by LCAC,"
Marine Corpds Gazette (January 1986) ,p.76.
  11Ltjg Kenneth Heine, "Beyond the Beach," Surface
Warfare (Jan/Feb 1988),p.11.
  12TACMEM0,P. 5-2.
  12TACMEMO,p. 5-2.
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