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Armed Escort For The Future
CSC 1993
                         EXECUTIVE SUMMARY
Title:   Armed Escort for the Future.
Author:  Major Thomas R. Kovach, United States Marine Corps
Thesis:  To maintain a viable amphibious assault capability the
Marine Corps must adopt an attack aircraft that is capable of
escorting the next generation of medium-lift aircraft.
Background: The Marine Corps will have a continuing requirement
to maintain a powerful airborne amphibious assault force to
augment expeditionary warfare.  This assault scenario calls for
attached armed escort aircraft to protect the transport aircraft.
Currently the AH-1W provides marginal escort to an aging fleet of
CH-46E medium-lift aircraft.  The selection of a future escort
aircraft will have to consider the multipolar threat of the
future, capabilities  of the next generation of transport
aircraft, and economic constraints. Enhancements to the AH-1W will
not meet these projected criteria satisfactorily.  A modern escort
aircraft must be selected and developed immediately.
Recommendations:   An attack aircraft employing tiltrotor
technology should be adopted as the next generation of escort
aircraft for the Marine Corps.
Thesis:  The AH-1W Cobra currently provides a marginal escort
capability and will experience and even greater disparity as
future transport aircraft a re instituted.  To maintain a viable
amphibious assault capability the Marine Corps must adopt an
attack aircraft which will be capable of escorting the next
generation of medium-lift aircraft.  This aircraft is the
tiltrotor attack aircraft.
      I.    The need for escort
      II.   Current capabilities and shortfalls
            A.  Speed
            B.  Range
            C.  Fire control
            D.  Weapons
            E.  Navigation
            F.  Survivability
            G.  Numbers
      III.  AH-1W enhancements
      IV.   Future requirements
            A.  Future threats
            B.  Future assault support requirements
            C.  Future escort aircraft requirements
            D.  Cost effectiveness
      V.    Escort solutions
            A.  General solutions
            B.  The AV-8B
            C.  The tiltrotor attack variant
                1.  Specifications
                2.  Flight configuration
                3.  Survivability
                4.  Performance
                     ARMED ESCORT FOR THE FUTURE
      The new direction of the Navy and Marine Corps is to provide
the nation with Naval Expeditionary Forces that are capable of
operation forward from the sea.  One important way that the Marine
Corps meets this requirement is by maintaining a powerful
amphibious helicopter assault force capable of projecting forces
across hostile beaches and rapidly building combat power.  A
component of a successful helicopter assault is the employment of
attack helicopters to provide armed escort for the transport
helicopter flight.  The AH-1W Cobra currently provides a marginal
escort capability and will experience an even greater disparity as
future transport aircraft are instituted.  To maintain a viable
amphibious assault capability the Marine Corps must adopt an
attack aircraft which will be capable of escorting the next
generation of medium-lift aircraft.  This aircraft is the
tiltrotor attack aircraft.
      Transport aircraft use a combination of speed, mass, and
surprise to maneuver assault troops.  Currently, the Marine Corps
relies on an aging fleet of CH-46 medium-lift helicopters for
troop transport that will soon be replaced by either a more
capable helicopter or the MV-22 tiltrotor aircraft.  Regardless of
the airframe selected, transport aircraft are vulnerable to enemy
fire in the enroute, landing, egress, and emergency extract phases
of the flight.  Their large profiles and lack of maneuverability
present attractive targets.  They must be protected by either
timely warning or suppression of enemy small-arms, anti-aircraft
guns and missiles, and hostile aircraft.  The effective escort
aircraft must therefore be capable of maneuvering to identify
threats, suppressing enemy fires, navigating to the landing zone,
and coordinating supporting arms fire.  The AH-1W demonstrates
significant deficiencies in its ability to accomplish all of these
      Speed is the major advantage of helicopter assault lifts.
The CH-46 helicopter can move troops at a speed of 140 knots and
if adopted, the MV-22 will cruise at 275 knots.  (2:27) To
adequately escort a transport flight the attack aircraft requires
a dash speed with a 30 percent advantage.  This equates to 180
knots for the CH-46 or 340 knots for the MV-22.  With a dash speed
of 150 knots, the AH-1W requires the CH-46 to slow down and
nullifies any advantage offered by the MV-22.  Therefore, the
AH-1W can become an impediment rather than a complement to mission
      The range of an escort helicopter is important to maintain
flexibility.  If an escort has to fly maximum fuel profiles, it
will not be able to respond to the uncertainties present in
combat.  With a full load of ordnance, the AH-1W has a fuel
endurance of just under 2 hours.  Planning for rendezvous and
loiter time, this gives a combat radius of about 100 nautical
miles.  Although this range is adequate for some missions,
over-the-horizon operations are questionable and escort for
emergency extractions are virtually impossible.
      Although the AH-1W is configured to fire effective
suppressive weapons such as 2.75-inch rockets and 20-millimeter
rounds, it lacks a fire control computer.  Since escort aircraft
must be able to effectively suppress threats that cannot be
pre-identified (or they would be circumnavigated), ranging to the
target and a gun solution must be made on the spot.  Lack of even
the simplest fire control computer, which uses a laser range
finder and airspeed data system to compute a firing solution,
requires the pilot to guess where his hits will go and correct
with windage and elevation.  Most often this method results in
wasted rounds and ineffective suppression.
      The AH-1W does possess a modern heads up display (HUD) tied
to an effective air-to-air missile, the AIM-9.  However, because
the missile requires one of two wing stations available for the
anti-armor weapons Hellfire and TOW, the AIM-9 must often be left
behind in favor of a more practical ordnance load. (4:74) The slow
rate of fire of the 20-millimeter cannon is ineffective in
countering either helicopter or fixed-wing threats.  It is
unlikely that the transport flight escorted by AH-1Ws will posses
any anti-air capability
      Autonomous navigation to the target or landing zone appears
to be a rudimentary requirement for the escort aircraft.  The
escort must deviate from the planned route of flight to locate
threats but still find the landing zone on time.  The AH-1W has no
tactical navigation system such as inertial guidance or satellite
positioning to aid in location of the landing zone.  With no
moving-map display, navigation is accomplished by the pilot who is
also reacting to threats and coordinating supporting fires.  This
workload, particularly at night, invites errors and subsequent
mission failure for lack of currently available hardware.
      Survivability of the AH-1W itself is also a concern.  The
escort aircraft is ineffective if it cannot directly face a simple
threat.  The only armor onboard the aircraft is found around the
pilots' seats.  The rest of the aircraft is unprotected and major
components are not reinforced to sustain combat damage.  The
powerful engines are not separated by a ballistic-resistant wall,
which means that a catastrophic failure of one will probably
result in failure of the other. (4:74) Even the low threat found
in Grenada resulted in the loss of two Cobras similarly
protected.  Tactics dictate placing the escort aircraft between
the transports and the threat.  The "wall" provided by the AH-1W
is very penetrable.
      Lack of capabilities aside, the number of AH-1Ws in the
Marine Corps, currently 120, is inadequate to provide capable
escort packages for all Marine Air Ground Task Forces (MAGTFs).
(2:2)  Currently, a forward-deployed Marine Expeditionary Unit
contains four AH-1Ws.  Assuming that all four of these aircraft
are available for escort meets the minimum requirement of one
escort for every four transports.  However, combat losses,
maintenance availability, and anti-armor missions have
historically left the assault package short of escort aircraft.
Refueling and rearming also leave gaps of support in the mission,
which can only be compensated for by additional aircraft
      The Marine Corps chose the AH-1W as a successor to a long
line of combat-proven Cobra models.  Unfortunately, this choice
was based on time and funding constraints which made the decision
shortsighted.  The AH-1W airframe can be enhanced to nearly double
the payload with a 40 knot increase in speed (still well below
MV-22 escort requirement) only with great penalties in time and
money. (1:4) The Cobra will be well in to the second half of its
20 year service life by the time such current-technology
modifications are completed.  By this time, the medium-lift
replacement will be fielded.  If the MV-22 is selected, it will
still lack a suitable escort with regard to speed and range.
Spending money on Cobra enhancements will not solve the escort
      The only solution which guarantees the Marine Corps a capable
and technologically updated escort is development and procurement
of an entirely new aircraft.  Because the procurement system is
lengthy and not overly accommodating of changes, a careful
analysis of future requirements is necessary.  Three broad
considerations must be examined in selecting the escort of the
future.  They include an estimate of the threat, compatibility
with the transport aircraft, and cost-effectiveness.
      While the end of the Cold War is the end of a well-defined
major threat from a known direction, it is not the end of
world-wide threat.  The shift resulting from the end of the Cold
War, from a bipolar to a multipolar world, creates an
unpredictable future threat withe regard to direction, technology,
capability, and motivation.  Motivations for conflict may well be
driven by economic, political, and demographic factors, as well as
worldwide competition for trade.  As mission profiles of  the
MAGTF expand, countering the enemy will become increasingly
complex.  This situation will be further complicated by the
proliferation of high technology weaponry and equipment available
to Third World nations.  The Marine Corps' ability to accomplish
its mission will be directly related to its success in countering
the threat's capabilities in the areas of NBC warfare, IADS,
communications, electronic warfare, and advanced weaponry
      In defining the new direction of Naval Forces, the Department
of the Navy stresses the expansion of expeditionary forces to
project power from the sea.  This emphasis is derived from the
analysis that forces must be swift to respond, structured to build
power from the sea when required by national demands, able to
sustain support for long-term operations, and be unrestricted by
the need for transit or overflight approval from foreign
governments in order to enter the scene of action
      Recent examples which reinforce this direction include the
initial rapid response to meet the requirements for Desert Shield
and to provide humanitarian assistance to storm-battered
Bangladesh and the war-torn Kurds following Desert Storm.
      Future assault aircraft must meet several basic requirements
to meet such missions in the future.  They must be capable of
sustained over-the-horizon (OTH) operations from air-capable
amphibious ships and austere unimproved sites ashore.  Even as
Desert Storm intensified, Naval Forces responded to evacuation
requirements in both Liberia and Somalia.  Unfortunately, the
CH-53E helicopters had to complete their OTH mission unescorted
because the Cobras could not make the target without refueling.
If an aircraft is capable of self-deployment by aerial refueling
and compatible with operations on amphibious ships, the force can
reach most crises areas rapidly and without delay for over-flight
      It is safe to say that the future threat demands assault
aircraft that are ship-board capable, self-deploying, and
maintainable under austere and lengthy conditions.  Implied in
these requirements is the need for the aircraft to have
sophisticated navigation, communication, electronic
countermeasures, and a self defense against NBC warfare.
      More specific requirements for the escort are identified by
examining the capabilities of the transport helicopter.  The
Marine Corps has developed a Mission Needs Statement for the
CH-46E replacement to fulfill the requirement for a medium-lift
assault support aircraft.  (7:1) This aircraft, designated the MLR
for medium lift replacement, must be capable of operating off of
air-capable amphibious ships and have an OTH and self-deployable
capability.  (7:5) With a range of 200 NM and a speed of 180
knots, the MLR scheduled for fielding in 2010 should meet the
projected threat.  (7:7) Fore-runners in the MLR competition
include a Sikorsky conventional helicopter and the Bell-Boeing
MV-22 tiltrotor, both of which meet or exceed these
specifications.  Consequently, the future escort must be
compatible with these parameters.
      In a parallel program, the Marine Corps has developed a Draft
Mission Needs Statement for a future attack aircraft to replace
the Cobra, UH-1N, and OV-1OD.  (5:8) A complete list of
requirements can be found in Tab A.  This aircraft has been
designated the VMAO because it covers the attack, utility, and
observation roles of the three aircraft it will replace.  (5:8)
The MNS envisions the VMAO as a tandem seat, 20 to 25 thousand
pound maximum gross weight aircraft with a mission configured,
unrefueled range (sea level standard day) of 500 NM, a sustained
operating envelope of -45 KTAS to 325 KTAS, and a 30 minute dash
speed of no less than 350 KTAS.  (5:9) It must be capable of
routine shipboard operations with rolling/pitching deck conditions
up to a maximum deck displacement of 15 degrees roll and +or- 3
degrees pitch.  (5:9) The aircraft must be capable of engaging and
disengaging primary flight propulsion systems (engines, rotors,
proprotors) in winds of 45 knots from any direction.  (5:9)
      The VMAO aircraft will be capable of accomplishing assigned
missions at low level and NOE altitudes at high and low speeds,
during day/night operations, in adverse weather and during periods
of reduced visibility.  (5:9) Over-the-horizon operations will be
possible with the inclusion of a precision navigation system and
long range, low altitude, jam resistant communications equipment.
      Survivability has been carefully considered in the VMAO
specifications.  A ballistic tolerance to 14.5 millimeter rounds
and crashworthy components are included in the design
requirements.  (5:10) Economical incorporation of low observable
radar, IR, and acoustic signatures will be designed into the
airframe.  (5:10) A fully integrated defensive countermeasures
system will assist in identifying and decoying anti-air systems.
(5:11) The enclosed cockpit will provide NBC protection up to MOPP
IV and zero-speed, zero-altitude ejection seats.  (5:10)
      The VMAO will have a self-deployable range of 2100 NM with
internal and external fuel tanks full.  (5:10) This flight will be
completed in under 10 hours with defensive ordnance aboard.
(5:10) An inflight refueling capability will further extend the
ferry limit.
      Advances in avionics will give the VMAO an unprecedented fire
control system tied into the HUD and a visor display.  (5:11) A
FLIR/TV will give a night delivery system compatible with all
on-board weapons.  (5:11) A minimum load of 12 precision guided
munitions, 38 rockets, 2 AIM-9X, and 1500 rounds of 20/25
millimeter ammunition will is specified.  (5:10)
      The VMAO will be cost effective for several reasons.  Its
design will make it suitable for a variety of additional
missions.  As stated in the draft MNS, the VMAO will take the
place of the AH-1, UH-1, and OV-10. The VMAO will therefore be
capable of performing close-in-fire support missions, command and
control, utility transport including recon insert and extraction,
and observation for the Marine Corps.  In addition, this platform
is attractive to the other services for such roles as
anti-submarine warfare, combat search and rescue, and special
operations.  The VMAO will save money in the long term by
providing a multi-mission aircraft which will have joint
applications and maintenance cost-saving commonality.  Additional
savings will be realized in the force reduction of strategic lift
currently required to deliver many of the platforms that the
self-deploying VMAO will replace.
      The issue now remains to identify an aircraft either
available or near development that can meet the future threat, be
compatible with the MLR, and be cost effective.  From an assault
support escort view, there are at least seven platform concepts
that meet the previously discussed criteria. The General Electric
XV-5A Remote Fan, the Canadair CL-84-1 Tiltwing, and the Sikorsky
XH-59A Advancing Blade Concept Aircraft as well as tilt-duct and
fan-in-wing concepts all warrant further investigation.  (5:8)
However, only two platforms are flying today in the form of the
McDonnell Douglas AV-8B and the XV-15 tiltrotor demonstrator
developed by Bell Helicopter Textron, Inc. to test concepts for
the MV-22 Osprey.
      The AV-8B Harrier is at first glance a likely escort for the
MLR.  It is already fielded, combat proven, and forward deployed
in the Marine Corps.  However, while the Harrier can work off of
amphibious ships and hover, it pays a tremendous price in payload
and endurance for operating in this regime.  The Harrier has just
over an hour of usable time in an attached escort role making it
unsuitable for just about all amphibious assault roles.  It is an
excellent detached escort and will necessarily be limited to that
mission in support of an assault force.
      The XV-15 tiltrotor demonstrator has the speed and range to
escort any future helicopter as well as the MV-22.  An attack
variant based on this model is one solution to the escort problem
that guarantees the Marine Corps a future capability.  Bell
Helicopter has taken the data collected from XV-15 tests to
conceptualize an attack variant that utilizes current technology.
Bell calls this aircraft the Tactical Tiltrotor (Gunship) or
TTR(G).  (8:2) The airframe considered is only slightly larger
than the XV-15 with the same blade diameter (25 feet) and a wider
blade chord to enhance low speed maneuver capability.  (8:2) The
overall size is comparable to most present day attack aircraft.
At 59.5 feet it is smaller than the AV-8B, although the laterally
displaced rotors make it wider than the Cobra by 10 feet.  (8:2)
Folded, the TTR(G) presents a suitable shipboard footprint.
      The aircraft is sized for a crew of two in tandem with the
forward cockpit used for the command pilot.  (8:2) Weapons
capability and flight controls are provided in either cockpit such
that single pilot operation from either seat is available and the
split of duties between the crew is flexible and can be tailored
to mission need.  (8:2) The flight controls are designed around a
rate command, attitude hold system similar to the F-18.  (8:2)
This control logic permits hands off flight in which the aircraft
will continue to fly or maneuver in accordance with its last pilot
input until pilot control is reestablished.  This capability
lessens the crew workload on escort missions and provides greater
margin of safety particularly at night and over water.
      The TTR(G) mirrors the high technology in developed for the
MV-22.  Using state-of-the-art construction with composite
materials (such as graphite fibers) gives this escort inherent
survivability.  (7:20) The material does not heat up significantly
as does a metal fuselage, significantly reducing the infrared
signature sought by ground-to-air missiles.  Additionally,
multiple layers of woven graphite prevent the total penetration of
bullets and fragments and are resistant to crack
propogation. (7:20) This structure has a proven tolerance to
23-millimeter anti-aircraft rounds.  (7:20)
      The light weight of composite construction and the added
power gained by tiltrotor aerodynamics gives the tiltrortor escort
a high payload capability.  The TTR(G) is estimated to have a
useful load of 3980 pounds and a load of 10,870 pounds if a 400
foot takeoff roll is permitted.  (8:3) @This payload exceeds that
of almost all current attack aircraft.  This allows the inclusion
of navigation, avionics, and weapons systems that were previously
too heavy for helicopters to carry.  There will be no need to
commit weapon loads to a single threat in order to save weight.
The tiltrotor escort will carry a full mix of air-to-ground and
air-to-air weapons to give the transports a full range of
      The purpose of escort is to protect aircraft against ground
and airborne threats that cannot be avoided ( flown over, under,
or around ) or neutralized by defense suppression operations.
Assault support operations must include attached armed escort in
all but the most benign scenarios to ensure mission success and
protect U.S. lives.  The current AH-1W fulfills the escort role
only marginally and enhancements will be costly and lengthy in
time to complete.  Even enhanced, the Cobra will not be advanced
enough to escort the MLR.  The task at hand is to select an escort
that will meet the future threat and compliment the next
generation of transport aircraft in an economical manner.  The
development and procurement of the tiltrotor attack variant is the
only guarantee that the next generation of assault aircraft will
have the escort that Marines under fire deserve
                             TAB A
                       VMAO REQUIREMENTS
      (1)   Capable of sustained (OTH) operations from air-capable
amphibious shipping and austere unimproved sites.
      (2)   Dual engine aircraft with autonomous self-starting
capability.  The aircraft shall be capable of powering all onboard
systems for maintenance or pre-mission tests through its integral
auxiliary power unit.  It shall also provide sufficient power for
engine starting while powering critical mission equipment without
power interruption.
      (3)   Have sufficient engine power so that with one engine
inoperative, cruise flight may be continued with full ordnance
payload and sufficient fuel onboard to fly either the point of
intended landing or return to the point of origin, whichever is
shorter, and land (STOL) with a ground or deck roll of less than
100 feet (with a 15 knot headwind).
      (4)   In the event that all engine power is lost while in
flight, the aircraft must be capable of a power off
glide/auto-rotation to a survivable emergency landing.
      (5)   Minimum 30 percent dash speed advantage over the MLR.
      (6)   An expanded flight envelope and "g" range commensurate
with air-to-ground and air-to-air flight profiles (minimum desired
range -1.5 to +5.0).
      (7)   Capability to conduct continuous/extended (over 30
minute) hover operations while mission configured, without
significant degredation to aircraft range, performance, and time
on station.
      (8)   Have a self-deployable range of 2100 NM when configured
with a full internal fuel load and external fuel tanks.  Retain
the capability to upload 2 AIM-9X missiles and 750 rounds of 20/25
millimeter ammunition when in the ferry configuration.  Complete
the 2100 NM flight in not greater than 10 hours.
      (9)   Have an inflight refueling capability.
      (10)  Expanded ordnance payload capability ( multiple
universal weapons stations which facilitate and aircraft
configuration of not less than 12 precision guided weapons, 38
rockets, 2 AIM-9Xs, or an equivalent load.  The VMAO will be
configured with an internal/ turreted gun capable of employing
1500 rounds of 20/25 millimeter ammunition.
      (11)  Ballistic tolerant ( at least 14.5 millimeter)/
crashworthy cockpit and critical components.
      (12)  NBC protection up to MOPP IV level.
      (13)  Economical incorporation of low observable radar, IR,
and acoustic signatures.
      (14)  Onboard, state-of-the-art mission planning system/data
loader (paperless cockpit concept).
      (15)  Fully integrated observation (enhanced optics
day/night with multi-powered zoom lens capability), detection,
navigation, communication, and targeting systems, combining active
and passive means to acquire, designate, and engage targets at
ranges in excess of 10 kilometers.
      (16)  Heads-Up/ Heads-Out cockpit design.  A computer driven
holographic HUD capability, or existing state-of-the-art visor
display systems, which facilitate mission accomplishment and the
projection of FLIR/TV imagery in a heads-up/ heads-out manner.
      (17)  Hands on Collective and Cyclic (HOCAC) cockpit design.
      (18)  Fully integrated defensive electronic countermeasures
system capable of identifying, displaying, prioritizing and
jamming/ decoying anti-air warfare systems to include ground and
airborne delivered Anti-Tank Guided Missiles.
      (19)  Long range (OTH) precision navigation capability.
      (20)  an offensive air-to-air capability superior to
anticipated threat helicopter/ tiltrotor and low performance fixed
wing aircraft.  A self-defense capability against high performance
fixed wing aircraft.
      (21)  Capability to transmit and receive digital data burst
information from/ to ground and airborne platforms.  Capability
for real time data link of FLIR/Optical imagery to/ from ground or
airborne receivers.
      (22)  Capable of sloped landings and take offs up to a
maximum displacement angle of greater-than or equal-to 15 degrees.
      (23)  Incorporation of zero/ zero ejection seats.
      (24)  Long range (OTH), low altitude, secure and jam
resistant communications capability.  (5:10)
1.     AH-1W Supercobra 4-Bladed Rotor System.  Pamphlet published
            by Bell Helicopter Textron, 1992.
2.     AH-1W Supercobra: The Smart Choice for the l99Os and
            Beyond.  News release by Bell Helicopter Textron,1992.
3.     Creech, Colonel Jim.  "An Enigma: Armed Escort for the
            Osprey."  Amphibious Warfare Review Winter 87-88:
4.     Darling, Colonel Buck.  "Warfighting the V-22." Amphibious
            Warfare Review Spring 89: 26-31.
5      Draft Mission Need Statement for an Advanced VTOL Attack/
            Observation Aircraft (VMAO).  Headquarters Marine Corp
            Department of Aviation.  5 May 92.
6.     Gibson, Major Mark J. and Major Barry M. Ford.  "Do Grunts
            Deserve the AH-1W Super Cobra?" Marine Corps Gazette
            September 90: 71-76.
7.     Gisold, Major Gary.  "The V-22 and the Future Threat."
            Amphibious Warfare Review Spring 90: 18-21.
8.     Magee, John P.  "Tactical Tilt Rotor." American Helicopter
            National Technical Specialists' Meeting on Tactical V/
            STOL Aircraft.  New Bern, North Carolina.  19-21
            September 89.
9.     Operational Requirement Document for the Medium Lift
            Replacement Aircraft (No. AAS 34.4) Marine Corps
            Combat Development Command.  4 May 92.
10.    Scheure, Doctor W.J.  "Escorting the Osprey." Amphibious
            Warfare Review Exposition Issue 86: 107-112.

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