VSTOL Revisted
AUTHOR Major Joseph J. Krejmas, Jr., USMC
CSC 1989
SUBJECT AREA - Aviation
EXECUTIVE SUMMARY
TITLE: VSTOL REVISITED
I. Purpose: To analyze the history of VSTOL aircraft in
the Marine Corps and define future applications of the VSOL
concept.
II. Problem: The United States Marine Corps has expended
a considerable amount of time and effort promoting VSTOL
aircraft. Critics have charged the AV-8B is ineffective on
the battlefield. A resolution of the facts is necessary to
allow for future growth in the VSTOL concept.
III. Data: As the AV-8B Harrier replaces the A-4M and
AV-8A, it becomes the only light attack fixed wing aircraft
in the Marine Corps. During this replacement the pilots
flying the aircraft have been assessing this new aircraft
and its capabilities. The AV-8B is more effective because
of improved reliability and maintainability. Moreover, the
AV-8B VSTOL capabilities are superior when compared to the
AV8-A. However, in terms of survivability in the air-to-air
arena and accuracy in its air-to-ground capability, the
AV-8B is equal at best when compared to its predecessors.
During its early years, the VSTOL concept faced a great
deal of criticism. This criticism was largely due to the
expected limitations that VSTOL technology would bring
forth.
IV. Conclusion: The Harrier's success and future of VSTOL
for all the services depends upon the commitment of the
Marine Corps to support this advanced technology. The
Marine Corps has been steadfast in its commitment to
promote VSTOL. The AV-8B is providing the necessary
operational experience to allow the future development of
third generation VSTOL fighter/attack aircraft that will
serve the Marine Corps needs from the year 2000 and beyond.
V. Recommendation: The Marine Corps continue to develop
operational experience using current VSTOL aircraft. Gain
further operational experience using second generation
VSTOL aircraft to enable the Marine Corps to develop third
generation VSTOL aircraft.
VSTOL REVISITED
OUTLINE
Thesis Statement: With planned improvements to the engine,
airframe, weapons system, and pilot training, the AV-8B
Harrier will continue to provide the Marine Corps with the
Offensive Air Support (OAS) necessary to win on today's
modern battlefield. In addition and perhaps more
significantly it will provide the operational experience
necessary to develope third generation VSTOL fighter/attack
aircraft for the year 2000 and beyond.
I. VSTOL History
A. Historical Overview
B. VSTOL Development
C. First Generation VSTOL
D. Second Generation VSTOL
1. Replacement of USMC A-4 and AV-8A/C
2. Second Generation Performance
II. AV-8B Equipment
A. STOL vs VTOL
1. Enhancements
B. Air-to-air Survivability
1. Deficiencies
C. Air-to-ground Capabilities
1. Deficiencies
D. Future Battlefield Performance
III. VSTOL Flexibility
A. Historical Overview
B. VSTOL Growth
C. VSTOL Tactical Applications
IV. VSTOL Advancements
A. Advancements in engine technology
B. Advancements in airframe technology
VSTOL REVISITED
When Marine pilots received their first combat experi-
ence in France during World War I, the first Marine avia-
tor, Alfred A Cunningham remarked, "The only excuse for
aviation in any service is its usefulness is assisting
troops on the ground to successfully carry out their opera-
tlons ."1 From that moment on, the Marine Aviator has
provided the Ground Commander a potent combat arm that has
become a keystone in determining the outcome of numerous
battles. The techniques learned in Nicaragua from 1927-1933
formed the basis of what we now call the "air-ground" team
in the Marine Corps. As developments continued and time
elapsed the Marine Corps task organized its Aviation Combat
Element to more efficiently do its job. These develop-
ments, once formalized, resulted in defining the six func-
tions of Marine Corps aviation as we know them today.
The United States Marine Corps needs light attack avia-
tion to support amphibious and ground forces wherever con-
flict occurs in the world. Therefore, Offensive Air Sup-
port, one of the six functions of Marine Air/VSTOL (Verti-
cal and short takeoff and land) applications will become a
primary focus of this discussion as it relates to the AV-8B
Harrier VSTOL aircraft. To accomplish a portion
of its Offensive Air Support, namely Close Air Support, the
Marine Corps has chosen the AV-8B Harrier as its premier
Close Air Support (CAS) aircraft. With planned improvements
to the engine, airframe, weapons system and pilot training,
the AV-8B Harrier will continue to provide the Marine Corps
with the Offensive Air Support (OAS) necessary to win on
today's modern battlefield. In addition and perhaps more
significantly, it will provide the operational experience
necessary to develope third generation VSTOL fighter/attack
aircraft for the year 2000 and beyond. The capabilities and
limitations of the Harrier asset are not well known within
the Marine Corps and are less understood by our sister
services and allies. A thorough understanding of this asset
and developing technology will assist the Ground, Naval,
and Theater Commanders in the proper procurement and employ-
ment of this valuable combat asset.
The events of World War II determined the parameters by
which future wars would be fought. The importance of air
operations and the need for secure airbases was emphasized
by the German invasion of Europe and the determination by
which the German forces sought to capture or destroy oppos-
ing forces airfields. The Japanese followed a similar path
during the early portion of the Pacific War with attacks
that focused on air facilities located on the islands of
Wake and Midway. Similarly, a major planning factor in
Operation Overlord, the invasion of Europe, included the
availability of air bases.2 These factors initiated coun-
teraction that form the basis of aircraft design and employ-
ment today. The use of highways for runways, camouflaging
airfields, hardening airfield support facilities, dispers-
ing aircraft around airfields, and VSTOL applications re-
sulted from the use of logical deduction and some trial and
error, all of which achieved the desired result.
As a result of experiences during World War II and the
Korean conflict, the Marine Corps recognized air support
needed to be more flexible when airborne and while on the
ground. Technological advances in aircraft performance and
capabilities increased with a resulting requirement for
increased basing support. The necessary basing support
increased so rapidly for fixed wing jet aircraft that it
limited the flexibility and operational utility of those
assets. No longer could the Marine Corps operate off of
roads or grass strips. Instead, an increasingly large run-
way was necessary to operate safely and within the design
specifications of the aircraft. Compromises with runway
length resulted in undesirable reduced gross weight take-
offs or a loss in safety. Other attempts to construct air-
fields of aluminum planking proved successful. However, the
bulk of material required and the fact that it had to be
moved and installed made it impractical.:
The Marine Corps solution to this problem was stated in
1957 by General Randolph McC. Pate USMC, the residing Com-
mandant of the Marine Corps. Col R.A. Gustafson USMC in his
1981 Advisory Group For Aerospace Research & Development
(AGARD) conference proceedings entitled "Ten years of U.S.
Marine Corps Harrier Operations" summarized General Pate as
follows:
The obvious solution to the problem was
to obtain aircraft which could operate
independently of large prepared airfields
Additionally, such an aircraft would
conceivably increase the number of ships
from which tactical aircraft could
operate, further increasing depletable
and operational flexibility. The Marine
Corps, therefore, has made a commitment to
VSTOL tactical aircraft because of their
perceived potential to combine the speed and
firepower of modern jet aircraft with a
unique basing flexibility.. .4
Commandant Pate's letter to the Chief of Naval Operations
formalized the Marine Corps requirement for VSTOL aircraft
by saying: "Vertical takeoff and land characteristics are
an ultimate requirement for all Marine aircraft in support
of amphibious operations in the future... Obtaining a
STOL/VTOL capability is vital to Marine Aviation. "5 By
1963 the needed technological advances made it appear that
the concept of VSTOL aircraft could be competitive with
conventional aircraft. Therefore, that year the Marine
Mid-Range Objective Plan stated: "VSTOL capability will be
included in the requirement for any aircraft if it provides
a worthwhile improvement in operational effectiveness with-
out unacceptably degrading flight performance or unduly
increasing overall support and maintenance."6
In 1971 the Marine Corps received its first AV-8A Harri-
er. These aircraft, for all practical purposes, could be
considered a prototype first generation VSTOL aircraft.
Like first generation helicopters and fighters of the past,
the AV-8A performed in a limited capacity by today's stan-
dards of airspeed, combat ceiling, maneuverability, range,
and endurance while carrying a combat load. However, the
importance of its introduction should not be underrated. In
fact, the AV-8A Harrier exceeded all expectations including
aircraft accident rate which critics charged was signifi-
cantly higher than Conventional Take Off and Landing (CTOL)
aircraft. The AV8-A has not had an accident rate that is
exceptional when compared to the initial accident rates of
high performance CTOL aircraft.7 As a first generation
VSTOL aircraft, the AV-8A served the Marine Corps well by
gaining the operational experience necessary to enhance the
introduction of a second generation VSTOL aircraft.
In 1984 the Marine Corps second generation VSTOL, the
AV-8B, was introduced to the fleet. The AV-8B replaces the
AV-8A/C and the A-4 to become the only light attack fixed
wing aircraft in the Marine Corps. The AV-8B offers consid-
erable improvements over the AV-8A. Due to design changes
that incorporated a stronger, larger graphite epoxy wing,
the AV-8B has twice the payload or radius capability of the
AV-8A. In the vertical takeoff mode, the AV-8B can carry a
payload of 6000 pounds of fuel and munitions.8 With a
short takeoff roll (STO), the AV-8B payload can be in-
creased to 17000 pounds.9 In this mode, using a takeoff
roll well under 1500 feet, the AV-8B is advertised to be
able to fly a hi-lo-hi-mission profile over a range of 615
nautical miles while carrying seven Mk 82 (500 pound)
bombs.10 These figures demonstrate a considerable improve-
ment from first generation VSTOL. Other improvements in the
area of avionics, weapons systems, engines, and airframe
improvements combine to make the AV-8B a state-of-the-art
VSTOL aircraft.
VSTOL aircraft have had their share of critics through
the years. Despite the overwhelming need for more flexibili-
ty on the battlefield, VSTOL aircraft have not been widely
recognized as a future application of air-to-ground or
air-to-air combat. The Marine Corps has recognized this
opinion but has remained steadfast in its commitment to
introduce follow-on second generation VSTOL aircraft. Most
early objection to VSTOL technology and applications have
been quelled with the introduction of second generation
VSTOL. One of the reasons VSTOL technology has been accept-
ed so slowly is the perception that combat aircraft have to
take off and land vertically. The resulting payload and
range performance make VTOL aircraft look quite unattrac-
tive by today's CTOL standards. VTOL technology is consider-
ably behind STOL technology and should be considered sepa-
rately when discussing take off and range performance of
aircraft. AV-8B VTOL performance was improved substantially
when compared to the AV-8A. However, the biggest improve-
ment for the AV-8B over the the AV-8A is in the STOL
mode.11 The improvement in STOL performance can be direct-
ly related to the improvement in VTOL capability which
postulates that the two performances are somewhat interre-
lated. There have been numerous VSTOL technology develop-
ments in the past few years to warrant continued emphasis
on STOL technology. Near term, the Marine Corps must uti-
lize its operational experience in second generation
VSTOL aircraft to reinforce current/future applications
with emphasis on STOL advancements. A corresponding advance-
ment in VTOL performance, like that experienced with the
AV-8B, should result from advanced STOL technology applica-
tions. The utility of this performance to support modern
battlefield situations should not be overlooked with regard
to future applications.
Another reason VSTOL technology has been accepted so
slowly is the perception that the AV-8B is an end all in
VSTOL technology advances. This could not be further from
the truth. In fact, limitations of this second generation
VSTOL aircraft will have to be resolved before a third
generation VSTOL aircraft can fly.
In terms of survivability in the air-to-air arena, and
accuracy in its air-to-ground capability, the Harrier is at
the very best, equal when compared to the aircraft it re-
places. With the assigned tactical missions of Close Air
Support (CAS) , Deep Air Support (DAS) , Armed Reconnaissance
(ArmRecce) , Helicopter Escort (HE) , and Anti-Air Warfare
(AAW) the Harrier can expect to fly several of its tactical
missions on one sortie. Given the Marine Corps has adopted
Maneuver Warfare as its official doctrine, the Harrier's
use on the modern battlefield will be increased to support
multiple maneuver elements that are envisioned. The modern
battlefield will consist of large numbers of troops support-
ed by assault helicopters or VTOL aircraft such as the
MV-22. It is easy to conceive that the battlefield in the
years 2000 and beyond will be fluid and anything but linear
in nature. It is also easy to imagine that attack aircraft
will have to penetrate enemy airspace to perform all its
assigned missions. The added requirement for increased
support in CAS, HE, and AAW will make it necessary to oper-
ate the Harrier forward for longer periods of time. In
these scenarios, the use of Harriers for AAW missions is
almost certain because of their forward location and the
requirement for self protection. The vulnerability of the
Harrier and the aircraft it would be escorting on a typical
HE mission becomes more evident when you realize the limita-
tions of the Harrier as it is presently configured. The
lack of radar makes the Harrier vulnerable to enemy
anti-air aircraft on all assigned missions.
It has been argued that the Harriers primary mission is
CAS and therefore does not need radar. Although this is
true, the fact remains that all aircraft have multiple
missions. The Marine Corps can not afford to buy an air-
craft with only one use. In the case of the Harrier, its
primary use is CAS. However, its other missions are also
vital in assisting the ground commander in accomplishing
assigned missions. Additionally, CAS with air superiority
will, at best, become a temporary phenomenon on the modern
battlefield. The expected nonlinear nature of the battle-
field further amplifies the thought that in future CAS
missions, the aircraft will not enjoy air superiority.
The Harrier must be responsive day and night and in bad
weather. It must be survivable, and possess the capability
to deliver all types of ordnance which can destroy all
kinds of targets. In future conflicts, Marine attack pilots
will enjoy momentary periods of air superiority. The remain-
der of the time will consist of occasional, if not routine,
excursions of friendly airspace by enemy attack and fighter
aircraft. Whether the mission is finding or shooting down
enemy aircraft before they bomb friendly troops (AAW)
destroying enemy follow-on forces or supplies before they
reinforce the enemy (ArmRecce) , or providing close air
support (CAS) , Marine light attack aircraft must possess a
state-of-the-art radar capability to exploit its position
on the battlefield. The ability of the attack pilot to
detect and react to the enemy is tantamount to survivabili-
ty.
History has shown us that technology is sometimes the
mother of invention. Regarding warfare, history is full of
examples where military technology enjoyed some of its
greatest success when employed in a manner that differed
from its original design. Aircraft carriers were originally
conceived as an improved scouting force for the fleet but
became a major offensive power. The P47 was designed as a
high altitude escort fighter but found its niche in low
altitude interdiction missions. The helicopter is perhaps
the best example of this. Originally developed during World
War II as a concept, the helicopter became useful during
the Korean conflict as a medical evacuation asset. Later it
operated in Vietnam as an assault support aircraft. This
function was not envisioned in its original design. The
Harrier may become this type of aircraft. A Close Air Sup-
port attack aircraft by design, it may become better em-
ployed as a helicopter escort aircraft. With the introduc-
tion of the MV-22, the use of the Cobra for escort will be
impractical given the airspeed differential between the
MV-22 and the Cobra. The only logical replacement for the
Cobra is the Harrier.
The one factor that is common to all these examples has
been operational experience. The experience is usually
obtained under combat conditions where cost is no factor
and innovative techniques and employment are encouraged.
However, the atmosphere during times of limited budgets and
peacetime rules-of-engagement tend to squelch innovation.
The Marine Corps introduction of the AV-8A as its first
operational VSTOL aircraft is an example of this phenome-
non. As a result, VSTOL technology has not been considered
a contender for fulfilling military missions. To date in
the United States, the Marine Corps is the only service
that has tested VSTOL capabilities on an operational
playing field Thus, VSTOL technology has not been allowed
to mature as rapidly as it could have.
The United States Marine Corps is a specialized fight-
ing force that uses Close Air Support as a principle sup-
porting arm. In areas of the world such as Norway, Close
Air Support is the Ground Commanders long range artillery.
Because of the topographical relief and the rugged terrain
of Norway, the Harrier may be the Ground Commanders only
form of long range fire support. This condition exists in
Europe, Korea, and other parts of the world as well. It is
this capability that the Ground Commander possesses that
makes him unique to all the combat services of the world.
Exploitation of the capability now can and will mean suc-
cess on tomorrows modern battlefield.
Experience has taught us that targets are extremely
time-sensitive. In the future, this factor will only become
more critical with the invention of more mobile enemy forc-
es. Therefore, targets tnust be taken under fire as soon as
possible or the opportunity may be lost. The alternative is
to allow the enemy to advance, dig in, and camouflage his
position. In this scenario, the detection and successful
destruction of these enemy positions is difficult. Converse-
ly, the timely detection and engagement of enemy forces
while he is on the move displays the most potential to
attaining successful destruction of the enemy forces. STOL
and VTOL aircraft can provide a quick response to a call
for fire. The alternative is CTOL aircraft that must loiter
near the battlefield and wait on target identification and
a call for Close Air Support. The cost of this loiter in
terms of fuel is unacceptable STOL and VSTOL aircraft of
the future will have to employ a forward basing concept
with enough fuel and ordnance to influence the battle.
Advances in engine technology over the last few years
have made such significant progress to suggest third genera-
tion VSTOL aircraft will possess increased thrust capabili-
ty. These advancements have resulted from decades of re-
search to find material that can withstand the temperatures
necessary to provide the great amount of thrust required to
operate in the VSTOL mode of flight. The engine design
industry has reached a point where no new metallic superal-
loys have been developed that are capable of withstanding
the heat and load requirements of the next generation of
engines.12 However, there is promise in two new types of
nonmetallic materials, carbon and ceramics. Both materials
possess properties that have tested positively under in-
creasingly high temperatures and loads. The results of
recent testing suggests that higher operating temperatures
of 2500 degrees Fahrenheit compared to 1900 degrees Fahren-
heit for metal components is possible.13 This break-
through in material development, if properly applied, could
lead to the materials necessary for the development of
third generation VSTOL aircraft engines. Future VSTOL air-
craft will have to be developed in a manner to take advan-
tage of new technologies in airframe improvements as well.
Some of the improvements now being considered for future
VSTOL aircraft include reducing size, masking infra red
sources, improving electronic countermeasures, and increas-
ing maneuverability with the use of vectored thrust. Of
these enhancements, the use of vectored thrust to increase
maneuverability appears to be most promising. These advance-
ments, coupled with the improved air-to-air missiles, will
make future VSTOL aircraft quite capable of self-protection
and performing AAW missions.
The AV-8B Harrier will continue to provide the Marine
Corps with the Offensive Air Support necessary to win on
today's and tomorrows battlefields. The operational experi-
ence gained by the Marine Corps commitment to the first
generation VSTOL provided necessary exposure to the opera-
tional fleet. This allowed for improvements in the air-
craft, engine, and more importantly the VSTOL concept it-
self. With improvements incorporated into the second genera-
tion AV-8B, the fleet is provided with a much more capable
aircraft than would have been designed had no previous
VSTOL experience been gained. The AV-8B Harrier is provid-
ing the necessary operational experience to allow the fu-
ture development of third generation VSTOL fighter/attack
aircraft that will serve the Marine Corps needs from the
year 2000 and beyond.
END NOTES
1MCDEC, USMC, Marine Aviation. FMFM 5-1,(Quantico,
1979) p. 1.
2B.H. Lindle Hart, History of the Second World War,
(New York: G.P. Putnam's Sons) , 1970, p. 59, 227-29.
3R.A. Gustafson, Col, USMC,"Ten Years of US Marine
Corps Harrier Operations," (HQMC, Defense Technical Informa-
tion Center, (AGARD) Conference Proceedings 313) , 1981,
p.4.
4Ibid p.4.
5Ibid p.4.
6Ibid p.4.
7P.T. Bingham, Lt Col, USAF, "Improving Force Flexibil-
ity Through V/STOL," Air University Review,
(January-February, 1985).
AIRCRAFT LOSSES
AIRCRAFT TYPE FIRST 90000 HOURS FIRST 213000 HOURS
AV-8A 25 50 (Includes
A-4 37 64 RAF)
A-7 37 73
F-8 44 79
A-6 16 33
F-4 17 44
F-100 39 78
F-102 27 38
F-104 43 88
F-105 31 47
F-106 15 26
A-10 08 17
F-15 04 15
F-16 10 30
8Ibid p.77.
9Ibid p.77.
10Ibid p.77.
11J.M. Byrnes et al., " Views on VSTOL Tactical Fight-
er Aircraft: Technology Needs and Relationships to the
Runway Denial Problem", (HQMC, Defense Technical Informa-
tion Center, (AGARD) Conference Proceedings 313), 1981,
p.8.
12G.M. Holloway and R.W. Meade, "Advanced Aircraft
Engine Exhaust Nozzel Development", The Leading Edge, Win-
ter 1988/1989, p.10.
13Ibid p.l5.
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