The Assault Support Helicopter, What Will It Be In The Future?
AUTHOR Major David A. Salzman, USMC
SUBJECT AREA Aviation
TITLE: THE ASSAULT SUPPORT HELICOPTER, WHAT WILL IT BE IN THE
THESIS: The Marine Corps must continue to provide the best
aviation troop transport aircraft to support future operations.
ISSUE: The extreme mobility gained by using helicopters in
tactical operations is a key ingredient in supporting the
maneuver warfare doctrine of the Marine Corps. The troop
transport helicopter is a versatile weapons system and is also
used for resupply, reconnaissance, medical evacuation and search
and rescue missions. An assault force embarked in helicopters
can bypass terrain obstacles and hostile areas rapidly moving
deep behind enemy lines, giving a commander the ability to
concentrate combat power at the decisive time and place.
The helicopter's use as an assault troop transporter evolved
shortly after the Korean War. New technology allowed the
helicopter to grow to a size that could carry a squad of
Marines. The concept of vertical assault by helicopter was
perfected in the Vietnam War. The CH-46 became the workhorse of
the Corps in a jungle environment penetrable only by helicopters.
The future plans of the Marine Corps were based on replacing
the aging CH-46 with the V-22. In the present age of defense
budget cuts, the V-22 is proving too costly to replace the
CH-46. Proposal options to replace the CH-46 are: a H-60 and
CH-53E mix; extend the life of the current fleet of CH-46's;
build new CH-46E's with upgrades; and build new CH-46X's with the
CONCLUSION: The technology and capabilities of the V-22 are too
great to shelve and wait. The Marine Corps will get some V-22's
and extend the life and upgrade the current fleet of CH-46's to
support the future operational needs of the Corps.
THE ASSAULT SUPPORT HELICOPTER,
WHAT WILL IT BE IN THE FUTURE?
THESIS STATEMENT. The Marine Corps must continue to provide the
best aviation troop transport to support future operations.
A. Troop transport
B. Internal and external resupply
C. Reconnaissance inserts and extracts
D. Medical evacuation
E. Search and rescue
II. Evolution of the troop transport
A. Korean War
B. Vietnam War
III. CH-46 replacement options
B. H-60 and CH-53E mix
C. Extend service life of CH-46
D. New production CH-46E
E. New production CH-46X
A. Need to go farther and faster
THE ASSAULT SUPPORT HELICOPTER,
WHAT WILL IT BE IN THE FUTURE?
The extreme mobility gained by using helicopters in tactical
operations is a key ingredient in today's maneuver warfare
doctrine of the Marine Corps. It allows Marines to operate in
areas well removed from their rear bases for extended periods of
time. Helicopters have made the advanced fire base a reality.
Helicopters used to insert and extract long range reconnaissance
teams provide a highly effective intelligence capability. Using
helicopters to regularly resupply troops has reduced the weight
troops must carry and their dependence on advanced supply
points. Helicopters give the commander the speed and mobility to
locate, close with and destroy an enemy over distances previously
impossible to cross.
Helicopterborne operations consist of movement of troops,
supplies and equipment. The helicopter's flexibility and
versatility permit a ground commander to reduce time and space
limitations normally encountered in the movement of assault
forces. An assault force embarked in helicopters can cross
terrain obstacles, bypass hostile areas, attack and destroy or
seize objectives deep in hostile areas. A commander is able to
concentrate the necessary combat power at the decisive time and
place. Once the desired result is obtained, he can rapidly
redeploy his forces where necessary.
The backbone of the helicopterborne assault is the troop
transport helicopter. This helicopter must be capable of
carrying squad size units. The numbers of troops in these squads
varies with the mission and usually consists of from thirteen to
twenty-three Marines. Equipment to support these squads ranges
from personal weapons to a jeep, which can be loaded internally,
to a variety of equipment that can be carried externally. This
helicopter must be capable of rapidly resupplying the assault
force because of the force's light posture. It must be able to
assume the secondary roles of rapid response to medical
evacuation and search and rescue. As new missions are conceived
and old ones refined, it must be able to support the demands of
the ground combat Marines. The Marine Corps must continue to
provide the best aviation troop transport aircraft to support
The idea of using helicopters for a vertical assault evolved
shortly after the Korean War. During the Korean War,
reciprocating engine driven helicopters were small and performed
such missions as rescue, reconnaissance, evacuation of casualties
and command and liaison flights. Between the Korean War and the
beginning of the Vietnam War, helicopters grew in size. During
the Vietnam War, the helicopter emerged as the workhorse of the
conflict. The availability of the right weapon at the right time
is no accident. It results from "thinking in terms of the next
war instead of the last. This means starting with ideas, when
you have nothing more tangible, and developing them into
concepts, procedures and weapons of the future."1
The reciprocating engine driven CH-34 was replaced by the
gas turbine driven CH-46 in March of 1966. The CH-46 could carry
more troops and cargo and get there faster. In 1968, helicopters
carried an average of fifty thousand men and over six thousand
tons of cargo a month. There is no doubt about it, the CH-46
saved countless lives in Vietnam. If the casualty could be
evacuated to a medical facility in short order, his chances for
survival were very good. In 1968, sixty seven thousand people
were medically evacuated with the CH-46 providing most of the
After four years of war, the missions of the CH-46 had been
established and tactics for those missions worked out and
"The CH-46 continued to perform the bulk of combat
and noncombat trooplifts and resupply missions;
and they carried out the important and hazardous
medical evacuation and reconnaissance team
insertion and extraction flights. The CH-46's
regularly flew about half of the helicopter
sorties flown each month."2
One particular operation, Dewey Canyon, was truly totally
dependent upon the helicopter. Lines of communication stretched
over fifty kilometers of rugged jungle and canopied mountains,
terrain penetrable only by helicopters. The success or failure
of the operation hinged on the skill and staying power of the
helicopter pilots. The initial fire support bases were secured
by CH-46's bringing in more than one thousand five hundred
Marines and forty six tons of cargo into two landing zones.
During the subsequent nine day period, CH-46's moved in and out
of the area on emergency missions carrying troops, ammunition,
rations, water and lifting out medical evacuations. Fighting
through weather, looking for holes in the overcast to drop into
Dewey Canyon, CH-46 pilots managed to move seven hundred eighty
seven thousand pounds of material and over one thousand troops.
The controversy of how many troops to carry in one
helicopter arose during the Vietnam War and still plagues Marines
today. The goal of a rapid troop build up in the landing zone by
using larger helicopters was weighed against the possible high
casualties if one of these helicopters was shot down. This
problem was best summed up by Major General Armstrong:
"If you have a defended zone, are you better
off to put twice as many people in a single
helicopter and take advantage of either
surprise or your suppressive capabilities,
getting in quickly, unload it and get out?
Or should you put half as many people in the
first one; and because of the lack of the
element of surprise and that pertains to not
only the fact that you're making the operation
but the direction of approach and everything
which is given away by the first troop-lift
helicopter and do you thereby so affect the
vulnerability factors that you greatly decrease
the survival (chances) of the second helicopter?"3
This problem of how many troops can you afford to lose in
one shot affects Marine Corps policy, strategy and tactics. The
use of CH-53 as an assault troop transport helicopter has
bothered the Marine Corps for years and still bothers it today.
The risk of losing large numbers of troops in peacetime if one
crashes outweighs the need to carry so many. It is never
acceptable to lose Marines in peacetime, and it is even worse to
lose large numbers. If this holds true in peacetime, it will
surely carry over to the battlefield.
The 1950's technology CH-46 has been out of production since
1971. The safety-reliability-maintainability upgrades done
during this overhaul were aimed at safe and efficient operations
until the V-22 deliveries could begin in 1992. The upgrades did
not extend the aircraft's service life of thirty years and ten
thousand hours. Some CH-46's have reached ten thousand hours and
increasing numbers of them will peak by 1993.
The V-22 was the aircraft designed to bring the Marines
ashore from over-the-horizon. With satellites watching our every
move, strategic surprise will be difficult to achieve.
Over-the-horizon operations will bring the tactical surprise
needed to build up the attacking forces ashore faster than a
defending force can bring it to bear. The enemy must be
convinced a surprise attack could occur anywhere over a large
area, thus causing it to keep its forces dispersed, limiting
their response time and ability to mass.
The Navy and the Marine Corps have invested over two billion
dollars in research and development of the V-22. Defense
Secretary Dick Cheney cancelled the program in last year's budget
saying the cost per unit was unaffordable. Congress restored
funding to continue the program's development. Cheney again
cancelled the V-22 in the 1991 budget sent to Congress.
With the cancellation of the V-22, the Marine Corps must
determine the best means for carrying out the assault helicopter
mission. One proposal by the Bush administration would replace
the V-22 with a mix of CH-53E and H-60 helicopters. The
Commandant of the Marine Corps, General Gray, dislikes this
idea. He feels the CH-53E was designed and built for logistic
support and endurance on the battlefield. He said before
"When you talk about using the CH-53E as an
assault helicopter, that in my judgment is wrong.
Sure you can haul troops with it in a certain
environment. We have done it many times. But
it's a logistics helicopter. It's not designed
to land on ridgelines at serious angles in the
assault. And it's got a radar signature that's
bigger than Capitol Hill."4
The H-60 carries about half the number of troops as the
CH-46. General Gray had this to say about the H-60:
"So we're going to have to get twice as many
helicopters, and we're not going to get that
are we? Nor are we going to get twice as many
pilots and twice as many crew chiefs in the
kind of environment (budget cut) that we're in
The price tag for the CH-53E and H-60 mix is very close to
the price tag for the V-22 depending on who is calculating the
figures. The Defense Department did not ask for any money for
the V-22 in the current budget. Congress appropriated two
hundred fifty five million dollars, telling the Pentagon to study
the V-22's costs compared to other aircraft. At this point, it
is a battle between the Pentagon and Congress and the CH-46 is
still getting older.
Another proposal is to extend the service lift of the CH-46
through the year 2020. Survivability, reliability, maintain-
ability, and safety are the key ingredients with economics being
the limiting factor. Upgrades and improvements must be cost
effective and operationally suitable for the CH-46 to perform day
and night in all weather conditions on the modern battlefield.
In 1978, airframe service life of ten thousand hours was
established for all rotary wing aircraft. This service life was
a planning figure and was based primarily on material degradation
(corrosion and wear) and fatigue which greatly influence long
term structural integrity. The ten thousand hour service life of
the CH-46 was based on qualitative information for planning
purposes only, not on actual fatigue testing. Fatigue testing
was not accomplished or planned for to certify the CH-46 past ten
thousand hours. Evaluation of CH-46 airframe fatigue analysis,
fatigue test results and service experience data indicate the
CH-46 airframe can be safety operated beyond ten thousand hours.
Flying past the ten thousand hour barrier will be possible, but
will demand additional maintenance inspections from squadron
through depot level. Some commercial BV-107 airframes have in
excess of thirty thousand hours on them.
There are numerous vital dynamic components that have a
service life of ten thousand hours or less on the CH-46. These
components will require replacement, fatigue tests and
modifications to provide a longer service. Some key dynamic
components to consider are the rotor system, drive system and
flight control system.
The rotor system consists of the rotor blades and rotor head
assemblies. The fiberglass rotor blades introduced in the early
1980's greatly reduced the number of maintenance man hours per
flight hour as compared to the old metal rotor blades. The blade
shape did not change, consequently aircraft performance stayed
the same. These blades are reaching their service life as well
as their rotor hubs. Rotor blade aerodynamic technology has made
great progress. New rotor blade designs made of composite
materials incorporated with a composite bearingless rotor hub
will be lighter. They will provide more lift and airspeed with
less chance to fail and demanding less man hours to maintain.
The transmission, gearbox and drive shafts will reach their
service lift and are becoming more expensive to rebuild.
Composite materials have been used in the Boeing 360's
transmission and gearbox casings. Rotor shafts and inter-
connecting shafts are also made of mixed-modules composite
construction. Composite parts are stronger and less likely to
fail, lower in weight and require less maintenance.
The CH-46 flight control system involves an intricate
network of push-pull rods and bell cranks coordinated by a
computerized automatic fight control system. Push-pull rods and
bell cranks can also be constructed of composite materials.
Composite materials are providing the extra lifting power
(payload) today as did the gas turbine in the 1950's. The use of
composite materials reduces weight and manufacturing costs. They
allow aerodynamically cleaner structures and remove a large part
of the fatigue problem, thus providing a much longer service
life. Composite materials use will increase payload capacity up
to twenty-five percent over that of current metal technology
aircraft. Other modifications and upgrades for the current CH-46
are improved avionics and navigation systems.
Another proposal is to start new production of the CH-46E as
quickly as possible. These helicopters would incorporate current
improvements and have the same configuration in which the last
CH-46 was produced. The Marine Corps would need approximately
one hundred new aircraft if the attrition rate of the fleet
remains the same. The listed configuration for the new CH-46E is
listed in Table 1.
Another proposal is to produce a new CH-46X that has the
configuration listed in Table 2 and upgrade all CH-46E models
into the X configuration. The upgrade would include modern
equipment developed for other programs, most notably integrated
controls and V-22 derived glass cockpit incorporated in the
MH-47E and MH-60K special operations forces helicopters. "The
CH-46X must be capable of carrying the TOW HMMWV (7900 lb)
externally and a crew of three internally for the mission radius
of fifty nautical miles."6 A thorough remanufacturing program
would give the CH-46X a service lift lasting well into the
2020's. This would give the Marine Corps a fleet of CH-46X's
about the same size as its current fleet of CH-46E's. Aircraft
numbers could be reduced if force levels are reduced.
NEW PRODUCTION CH-46E CONFIGURATION
SERVICE LIFE EXTENSION PROGRAM UPGRADE
DYNAMIC COMPONENT UPGRADE
ESTENDED RANGE STUB WINGS
COCKPIT MANAGEMENT SYSTEM
HELO EMERGENCY FLOTATION SYSTEM
NVG COCKPIT/CABIN IR FORMATION LIGHTS
IR EXTERIOR LIGHTING IR SEARCH/LANDING LIGHTS
IMPROOVED WHEEL ASSEMBLY PLRS
FUEL VENT VALVE IMPROVEMENT SECURE VOICE
SECOND ARC-182 RADIO HF RADIO (SECURE)
FATIGUE VIBRATION MONITOR ELT
VOR/ILS LASER WARNING RECEIVER
CRASHWORTHY TROOP SEATS FASTROPE HARDWARE
UPGRADED HEELS NVG HUD
LIGHTWEIGHT PILOTS SEATS STANDARD COMPASS
NEW PRODUCTION CH-46X CONFIGURATION
NEW PRODUCTION CH-46E
HAVEQUICK/SINGARS ZERO DRAG EEDS UPGRADE
SATCOMM WIRE DETECTION/WARNING
LIGHT WEIGHT ARMOR
NAVIGATION FLIR ENGINE UPGRADE
HELMET DISPLAY ROTOR SYSTEM UPGRADE
DIGITAL MAP REFERENCE SYSTEM 21 INCH CORD ROTOR BLADE
GLASS COCKPIT MANAGEMENT MISSION PLANNING SYSTEM
MFD'S INTERFACE WITH TAMPS
STANDBY INSTRUMENT PANEL AIRFRAME
DUAL, 1553 DATA BUSS
ONE EXTERNAL STORES RACK
DUAL POINT HOOK SYSTEM
Of all the options, the Marine Corps hopes the V-22 will
survive with Congressional support. Bickering between the
Congress, Pentagon and Secretary of Defense is only delaying a
solution to the aging fleet and dwindling part supplies of the
CH-46. The service life of the CH-46 can be extended and its
survivability and range improved. "We need to go farther and we
need to go faster if we are going to survive."7 We need all
weather over-the-horizon capability for the amphibious assault
ship-to-shore mission, greatly increasing mission success of the
aircraft and its crew. As General Gray stated:
"Fundamentally, you're at the upper edge of
the helicopter technology envelope. Therefore,
if you want to make a significant leap (in
capability), you're going to have to go a
Enduring the huge defense budget cuts and political
bickering, the Marine Corps may have to tailor its request for
new technology. There are many solutions to the aging CH-46
problem: a mixed bag of different aircraft; extending the life
of the old CH-46; building new CH-46's; and even getting some, if
not all, of the CH-46's replaced by the V-22. The Marine Corps
will probably get some V-22's to support the over-the-horizon
concept and the CH-46 will be upgraded and continue to act as the
workhorse of the Corps.
1 Major General Keith B. McCutcheon, USMC, "Getting There,
Any Way, Any Time," Armed Forces Journal, (July 26,
1969), p. 21.
2 Graham A. Cosmas and Lieutenant Colonel Terrence P. Murray,
USMC, U. S. Marines In Vietnam, Vietnamization and
Redeployment 1970-1971, (History and Museums Division,
Headquarters, U.S. Marine Corps, Washington, D.C., 1986),
3 Cosmas and Murray, p. 294.
4 Elizabeth Donovan and David Steigman, "Gray: V-22 Substitute
Scheme `Ridiculous,'" Navy Times, (March 5, 1990), p. 4.
5 Donovan and Steigman, p. 4.
6 Colonel J. P. Cress, USMC, Director, Naval Air Systems
Command Detachment, Cherry Point, North Carolina, letter
to Boeing Helicopters about USMC CH-46 Restart Program,
January 4, 1990.
7 Robert Holzer, "Replace Cancelled V-22," Defense News,
February 26, 1990), p. 3.
8 Donovan and Steigman, p. 4.
Bond, David F., "CH-46 Replacement May be CH-46X; Marines
Believe UH-60 Is Too Small," Aviation Week and Space
Technology, (February 19, 1980), p. 18.
Boyne, Walter J. and Lopez, Donald S., The Age of the Helicopter.
Vertical Flight, (Smithsonian Institute Press,
Washington, D.C.), 1984, pp. 221-245.
Cosmas, Graham A. and Murray, Terrance P., LtCol, USMC, U. S.
Marines In Vietnam, Vietnamization and Redeployment 1970-
1971, (History and Museums Division, Headquarters, U. S.
Marine Corps, Washington, D. C.), 1986, pp. 288-295.
Cress, J. P., Col, USMC, Director, Naval Air Systems Command
Detachment, Cherry Point, North Carolina, letter to
Boeing Helicopters about USMC CH-46 Restart Program,
January 4, 1990.
Donovan, Elizabeth and Steigman, David, "Gray: V-22 Substitute
Scheme `Ridiculous,'" Navy Times, (March 5, 1990), p. 4.
Holzer, Robert, "Replace Cancelled V-22," Defense News,
(February 26, 1990), p. 3, 49.
Linn, Thomas C., Maj, USMC, "Over-the-Horizon Assault: The
Future of the Corps," Marine Corps Gazette, (December
1987), pp. 44-47.
McCutcheon, Keith B., MGen, USMC, "Getting There, Any Way, Any
Time," Armed Forces Journal, (July 26, 1969), pp. 21-24.
Prina, L. Edgar, "Marine Aviation Tilts Ahead," Sea Power,
(November 1987), pp. 27-32.
Assault Support Helicopter Tactical Manual, NWP 55-9-ASH, Volume
1, NAVAIR 01-1ASH-1T, 1985.
NATOPS Flight Manual, Navy Model CH-46E Helicopters, NAVAIR
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