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. BIBLIOGRAPHY Anderson, S.B. "Historical Overview of V/STOL Aircraft Technology. Defense Technical Information Center, Advisory Group for Aerospace Research & Development Conference Proceedings 313, September 1981. Augustine, N.R. and Morrison, J.B. "Vertical Lift Capabilities For the `80s and `90s." Defense Technical Information Center, Advisory Group for Aerospace Research & Development. Conference Proceedings 313, September 1981. Bingham, P.T. LtCol, USAF. "Improving Force Flexibility Through VSTOL." Air University Review, January-February 1985. Byrnes, J.M., et al.,"Views on V/ST0L Tactical Fighter Aircraft: Technology Needs and Relationships to the Runway Denial Problem." Defense Technical Information Center, Advisory Group for Aerospace Research & Development. Conference Proceedings 313, September 1981. Cordier, Sherwood S. "Command of the Air at Sea: V/STOL and Small Carriers." Naval War College Review, July-August 1981. Gustafson, R.A. Col, USMC. "Ten Years of U.S> Marine Corps Harrier Operations." Defense Technical Information Center, Advisory Group for Aerospace Research & Development. Conference Proceedings 313, September 1981. Hart, B.H. Liddell. History of the Second World War,1970. Holloway, G.M. and Meade, R.W.. "Advanced Aircraft Engine Exhaust Nozzle Development." The Leading Edge, Winter 1988/1989. Holloway, James L. III, Adm, USN. "The Transition to STOL." U.S. Naval Institute Proceedings, 103 (September 1977). Kelley, Paul X., Gen, USMC. "One telephone Call Gets it All." Sea Power, 27 (November 1984). Lehman, J.. R. Maj, USMC. "Here Comes the AV-8B!" Marine Cords Gazette, 68 (May 1984. Lewis, Stanly P. Col, USMC. "V/STOL Close Air Support in the U.S. Marine Corps. U.S. Naval Proceedings,l02 (October 1976.) Lillie, J. C., LtCol, USMC. "Seabasing the Harrier." Marine Corps Gazette, May, 1987. McCalla, J.C., Maj, USMC. "AV-8B: Two Meanings to Air Support." Marine Corps Gazette, May, 1987. Murray, Russell, 2nd. "Rising Vertically through the Air, Invulnerable to Runway Cuts." Armed Forces Journel International, 118 (April 1981). Roberts, L. & Deckert, W. & Hickey, D. "Recent Progress in V/STOL Aircraft Technology." Defense Technical Information Center, Advisory Group For Aerospace Research & Development Conference Number 313, September 1981. Uhlig, Frank, Jr. "Assault by Sea." Marine Corps Gazette. 60 (June 1976). U.S. Marine Corps. Marine Corps Development and Education Command. Marine Aviation FMFM 5-1. Quantico, 1979.
