Gabriel D. Boehler

Professor of Aerospace and Mechanical Engineering

The Catholic University of America

Washington, D.C. 20064

MAJ William C. Schneck

Operations Officer, 1/170th Infantry

Ft. Belvoir, Virginia 22060

Ralph D. Zumbro

Distinguished author, Tank Aces, Iron Cavalry, Puma Force

1st Tactical Studies Group (Airborne)

Orlando, Florida

The new "Force XXI Operations" concept forms the basis for the U.S. Army’s attempt to dominate the future battlefield (Ref. 1). This is to be accomplished by exploiting the "Military Technical Revolution" through the creation of a highly mobile force capable of "Full-Dimensional Operations" across the width and depth of the battlefield. One way to make this concept a reality is through the development and fielding of a Very Heavy Lift Helicopter (VHLH). This VHLH should be capable of transporting the M1 Main Battle Tank (MBT) over a 100 nautical mile radius. This would provide a significant, possibly decisive, operational advantage over potential adversaries on the lethal modern battlefield. Such an aircraft is within the near term state-of-the-art for today's aerospace industry.

This paper examines the operational and technical issues associated with the proposed VHLH. The operational assessment includes an overview of the emerging battlefield and a cost effectiveness analysis based on doctrinal U.S. Army war gaming practices. The technical assessment includes a review of the state-of-the-art for the VHLH as well as size and cost estimates.

It is concluded that the VHLH appears to constitute one of the "leap ahead technologies" sought by the Department of Defense to insure U.S. battlefield supremacy in the twenty-first century (Ref. 2) and merits further study.

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Underline indicates air delivery into combat

Underline indicates air delivery

on the types of missions that such units can successfully execute. For example, the missions that the 101st Airborne Division could undertake during Operation Desert Storm were strongly influenced by their lack of armor and ground tactical mobility. Additionally, deteriorating weather conditions may severely restrict air support. This happened to the 3rd Brigade of the 101st Airborne Division after it was inserted more than 160 miles inside Iraq on the Euphrates River (Ref. 12, pages 110, & 188-189). In some earlier cases, the vulnerability of light infantry after a vertical envelopment has resulted in a incomplete mission completion as occurred to the British 1st Airborne Division at Arnhem ("A Bridge too Far") (Ref. 13), the Russian Dnieper River jump of September 1943 (Ref. 10, pages 91-111), and the French at Dien Bien Phu (Ref. 14). Even successful vertical envelopments have been limited in effectiveness or resulted in unnecessary casualties such as occurred to the Germans during the seizure of Crete which was compromised by Allied awareness of the mission via the breaking of the German codes (Ultra Secret) (Ref. 15, pages 119-147) and the Americans during Operations Husky and Overlord (Ref. 16, pages 207-248 & 353-417).

Current U.S. Airborne forces must normally seize an existing C-5/C-17 capable airfield before the buildup of heavier forces for follow-on operations can be undertaken. Large airfields are high value targets that are normally well defended and are present in limited numbers. Furthermore, it takes considerable time to build up armored combat power in this fashion. Additionally, Airborne operations require significant lead time to allow for planning and therefore lack the tactical flexibility of Air Assault operations for exploiting fleeting opportunities as they present themselves during a battle, though with digital mapping means the speed to conduct either type operations could be equally responsive.

The emergence of the helicopter as a major tactical player during the Cold War offered another possible solution to the problem of executing a successful vertical envelopment. The Soviets developed combined-arms units based on mechanized Airborne/Air Assault forces equipped with armored assault guns (ASU-85), infantry fighting vehicles (BMD), and self-propelled artillery (2S9 and BM-21). These could be delivered by the Mi-6 Hook or 26 HALO helicopter (Figure 5) to a range of 270nm (Ref. 17, pages 5-37 to 5-39, 5-56, 5-62, & 5-221 to 5-222). In the first heliborne combat operation conducted with an armored force, the Soviets inserted 6,000 men, 200 BMDs, and 70 ASU-57s using 30 Mi-8s and 10 Mi-6s. This operation was conducted in support of an Ethiopian attack against Somali infantry in prepared positions during the Ogaden War in 1978. This operation knocked Somalia out of the war (Ref. 18, pages 148-149). Other examples of strategic vertical envelopments with light armor include the Soviet seizures of Prague(1968) and Kabul (1979). In the seizure of Kabul, the 105th Guards Airborne Division (reinforced with regiments from the 103rd and 104th Guards Airborne Divisions) air landed two battalions of BMDs and one battalion of ASU-85s to support the seizure of the Afghan capital (Ref. 19). In the same vein, the Germans have fielded and employed the Wiesel armored fighting vehicle for deployment by UH-60, Puma, CH-47 or CH-53 (Ref. 20, page 11 & Ref. 21, pages 379-381). The UK has fielded and employed the Scorpion family of armored vehicles for deployment by CH-47 (Ref. 22).

U.S. efforts in this area have been limited to small-scale administrative moves of M113A1s by CH-47 or CH-54 in Vietnam. At present the heaviest lift helicopters available to U.S. Air Assault forces are the CH-47D (Army) and CH-53E (marines)(Figure 5). In the 1970s, development of the XCH-62 heavy lift helicopter was initiated by Boeing Vertol to carry 22.5 tons for 20 miles. The prototype was never completed due to budget and technical problems.

Although Airborne and heliborne forces supported with light armor (Tables 1 & 2) possess significant capabilities, they are still extremely vulnerable to conventional armored/mechanized forces. Given the widespread proliferation of tanks (Table 3), the likelihood of a lightly armored force being brought into a pitched battle by a more heavily armored force is significant and potentially disastrous.

*Does not include reliable allies such as Canada, Western Europe, Israel, Australia, and Japan

The ability to strike deep with armored/ mechanized units provided by the VHLH will force any future enemy to establish a defense in greater depth to counter this new threat to his vulnerable rear area logistic and command/ control/communications facilities. The "virtual presence" of such a capability will force an enemy to reallocate significant combat resources (including some of his armored/mechanized units) away from the main battle area. The resulting reduction in resources available in the enemy’s main battle area should also create weaknesses that can be exploited by a conventional ground attack. This same effect was shown during the Persian Gulf War by the deployments of the Iraqi Army along the Kuwaiti coast to counter the threat posed by an amphibious. assault by the marines that never came.

This capability will also have a significant deterrent effect by placing potential opponents in the impossible position of having more dispersed assets to defend than they have forces. Concentration of these assets for defense from ground attack will only provide more lucrative high payoff targets for air strikes.

Additionally, in nonlinear OOTW (Operations Other Than War) and Counterinsurgency environments such as Vietnam, the VHLH would significantly reduce the need for long vulnerable ground LOCs (Lines of Communication). As shown in Vietnam, Somalia, and now Bosnia, these LOCs constitute a critical vulnerability for U.S. ground forces. Given the uncertain strategic environment, it is important that the U.S. military retain the capability to fight under all foreseeable conditions of weather and terrain against all levels of threat to support national strategy.

Based upon the shortcomings of the battlefield scenario discussed above, through which it was clearly shown that weapons delivery by current deep attack assets are not sufficiently effective, it is proposed to discuss a mission in which an M1 series tank could be transported to the rear of the enemy and assume combat dominance in its area. Therefore, the primary mission of the proposed VHLH is to provide a U.S. theater commander with the capability to deploy, redeploy and recover an armored/mechanized task force of battalion strength 100 miles from the point of embarkation, in a single lift, and logistically support them for up to 48 hours. Allowing for the distance of the pick up zone from U.S. front lines and any separation between the combatants, this should allow the task force to be inserted up to 60 miles behind enemy lines. If necessary, a commander could sequentially insert and support four to five battalion task forces.

As a secondary mission, the VHLH would be used to deploy reserves to counterattack an enemy penetration or to reinforce/exploit an American breakthrough. Another secondary mission would be to provide rapid logistic support to forward-deployed units, particularly those executing a pursuit. This is a critical capability because mobile operations without sufficient logistic support will stall and degenerate into battles of attrition. For example, consider the Allied campaign launched across France in 1944 by Operation Cobra that culminated in the battles of attrition around Aachen, in the Huertgen Forest, and in the province of Lorraine. Also consider the German campaign in Russia in 1942 that culminated in the Battle of Stalingrad. Field Marshall Rommel was also forced to fight battles of attrition at Tobruk and El Alamein because of logistic considerations.

Since the mode of operation for the VHLH carrying an MBT has not been defined yet (speed, altitude, time on station, etc.), the threat must remain somewhat speculative. However, it will most likely be based on a Russian style air defense system. Against such a system, the VHLH would probably operate very close to the ground. In this case, the primary threat to the VHLH would be man-portable anti-aircraft missiles, anti-aircraft artillery, and small-arms fire controlled at the division level or below (Tables 4 & 5). The objective of this Russian style air defense system is to reduce the effectiveness of enemy air attacks.

(REF. 17, pages 5-114 to 5-137)

NOTE 1) All Russian MANPADS are vulnerable to suppressive fires and obscuration.

2) All current Russian divisional air defense systems are vulnerable to fragmentation.

3)All current Russian divisional air defense radars are vulnerable to ECM.

4) Most echelons above division Russian air defense systems have minimum altitudes in excess of 90m.

With a MRD (Motorized Rifle Division) in the defense, its air defense is oriented on providing a point defense against attacks on its first echelon motorized rifle regiments. It also receives incidental HIMAAD (High and Medium Altitude Air Defense) coverage from Army and Front assets (which have a minimum engagement

FIGURE 1. BATTLEFIELD DISPERSION & LETHALITY TRENDS (REF. 25, Page 7)

altitude of 90m). This air defense system is not intended to prevent the penetration of their airspace but rather to provide protection from attack to critical assets (Ref. 24, pages 11-1 to 11-12). Consequently, Airborne and Air Assault operations behind enemy lines remain viable options to U.S. commanders. In fact, the increasing dispersion of conventional combat units on the battlefield, the "empty battlefield" phenomenon (Figure 1), will make such operations easier to conduct even against improving air defense technology, particularly at night. As an example of the trend toward the "empty battlefield," the density of a Soviet rifle division in the defense has declined from about 6,000 men per km² during WWII to 65 men per km² in the modern MRD.

The VHLH can exploit the characteristics of this air defense system just as well as current U.S. Airborne and Air Assault units. Since target acquisition for most of these air defense systems is visual, night operations will further reduce the vulnerability of the VHLH.

Other emerging threats include air-to-air combat helicopters and fighters with look-down/shoot-down radar. Against these, air superiority will have to be assumed, which requires close coordination with other battlefield assets.

The VHLH is intended to function as part of a combined arms team during combat operations. This combined arms team would normally include infantry, armor, artillery, aviation, and combat engineers. Although the VHLH could theoretically deploy and sustain an armored task force more than 200 miles, this would require refueling at the landing zone deep in enemy territory. Furthermore, the range of current U.S. tube and rocket artillery is limited to 30 km and the range of MLRS fired ATACMS is 100 km (Table 6). Additionally, the ability of a corps to gather tactical intelligence is limited to about 130-140 miles (Figure 2). An armored task force operating outside this envelope is limited to about 6 miles. Corps intelligence support is critical. It is used to identify enemy air defense concentrations that should be avoided and to identify worthwhile opportunities to employ Air Assault forces in their deep attack role. It also provides critical early warning on enemy units moving against the task force. Therefore, the depth of operations is more limited by the ability of the corps commander to provide fire support, intelligence, and logistic sustainment than by the combat radius of the VHLH.

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During combat operations over hostile territory, the VHLH would be escorted by attack helicopters (with air-to-air combat capabilities) and supported by U.S. Air Force air supremacy fighters and air defense suppression aircraft when necessary. Local U.S. air superiority is required if Air Assault operations are to be effectively conducted. UH-60s, CH-47s, CH-53s, and V-22s could be used to deploy light forces when a heavy/light mixed task force is required.

Armored task forces inserted by air would normally operate in cooperation with conventional ground forces. The ability of a corps commander using a VHLH deployed armored/mechanized task force to strike his opponent in an unexpected manner and from an unexpected direction will greatly enhance the probability of achieving surprise (Ref. 27). Such surprise is critical to decreasing friendly casualties in personnel and equipment.

To sustain an armored battalion task force once it has been inserted requires approximately 41,720 gallons (292,000 lbs.) of diesel fuel, 55 tons of ammunition, plus lesser quantities of other supplies (such as food and water) per day. This amount of logistics will require 4 VHLH loads per day plus any additional sorties to evacuate equipment that cannot be quickly repaired in the field. Company teams could be resupplied in a "leap frog" fashion to maintain the momentum of an attack.

After the completion of its mission, the armored task force could be extracted from enemy held territory by several methods. These include linking-up with a conventional U.S. ground unit, seizing a piece of key terrain (and holding until relieved), or they could be extracted by air.

To execute a vertical envelopment with an armored task force, a theater commander will require a VHLH battalion of ninety aircraft. This is based on typical operational readiness rates and current U.S. aviation practice. Two of these battalions (see Tables 7 & eight for force structure requirements) should be fielded, one for each MRC (Medium Regional Conflict) required by national strategy. This results in a total of 200 aircraft (including 20 for schools and maintenance floats). The theater commander would normally commit his one VHLH battalion to support his main effort corps.

*Added weight for countermine equipment, these items would have to be transported separately to the landing zone and assembled there.

The military utility of the VHLH was analyzed using doctrinal U.S. Army war gaming practices (Ref. 28, Appendix F.). This is not a very sophisticated method of analysis, but it is one with which graduates of the Army’s Command and General Staff College are familiar. "War gaming is a conscious attempt to visualize the flow of a battle, given friendly strengths and dispositions, enemy assets and possible courses of action, . . . It attempts to foresee the action, reaction, and counteraction dynamics of a battle." (Ref. 29, page 4-1) The analysis was performed for a typical scenario with a U.S. Corps (of three mechanized infantry divisions with normal support units, Ref. 26, page 4-6) conducting a deliberate attack against a typical Russian style Motorized Rifle Division (of a field army of four MRDs) in a deliberate defense (Figures 3 & 4, Tables 9 & 10)(Ref. 17, page 6-5).

TABLE 10. PLANNING GUIDE FOR LEVEL OF UNITS TO BE ARRAYED (REF. 28, Page E-27)

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The war game, using Tables 11 & 12 was executed twice, once without the VHLH and once with the U.S. Corps augmented with a VHLH battalion. This war game was supported by the G-3 (Operations) and the former G-2 (Intelligence) officers of the 29th Infantry Division (VaARNG). The amount of time required to breakthrough the MRD’s defensive position was determined using Table 11. For the calculation of the time required when using the VHLH, it was determined that such an attack would achieve "substantial" surprise and reduce the defender from a prepared defense to a hasty defense because of the change in orientation required of the defender. From this, casualties and equipment losses were estimated using Tables 13 & 14.

U.S. tank battalions have an authorized strength of 58 M1 MBTs (five battalions per mechanized infantry division) with an additional 123 in the Armored Cavalry Regiment. The mechanized infantry battalions (five battalions per mechanized infantry division) have an authorized strength of 844 personnel and 60 Bradleys

TABLE 13. DAILY PERSONNEL LOSSES AS PERCENTAGE OF STRENGTH (REF. 33, Page 4-9)

TABLE 14. MATERIEL LOSS DATA (REF. 34, Page 1-8 & 1-9)

each. There are an additional 356 Bradleys in various cavalry units. Therefore, the Corps has an authorized strength of 993 M1 MBTs and 12,660 infantry with 1256 M2/3 Bradleys. Based on historical experience, the tank and mechanized infantry battalions are considered incapable of further offensive operations if their strength drops below 60% for personnel or critical equipment. Since 93% of total casualties normally occur in the infantry, corps casualties in excess of about 8,200 indicate that the corps is incapable of further offensive operations until it can receive replacements.

In the attack without the VHLH, the corps is expected to take over 8,200 casualties. This attack is also projected to lose about 2/3s of the assigned M1 MBTs and Bradleys, rendering the corps incapable of conducting further offensive operations (Table 15). Therefore, the corps must conduct a passage-of-lines to allow a follow-on force (from another corps or a reserve division) to conduct the exploitation of the breach of enemy’s main battle area. Such an attack is expected to take about four days to completely penetrate an MRD.

However, in the attack where the VHLH is used, the corps could expect about 4,200 casualties and 1/3 losses among M1s and Bradleys. Most importantly, it should have sufficient combat power remaining to continue the attack. This attack is expected to take only about one and a half days to produce a breakthrough of the enemy’s defense. A key element of Table 15 is the estimated cost of the loss of 25 VHLH (with five considered a total loss). As shown in the second part of this paper, the cost is estimated at $100,000,000 per aircraft.

Note 1) In accordance with Army doctrine, 80% of the "lost" items of equipment are assumed to be repairable given some time. The cost figures reflect this. However, their short-term non-availability results in a loss of momentum to the attack.

Note 2) A cost of $500k per Soldier lost was used. This is based on the standard $200k life insurance policy and the cost of his education and training.

A comparison of the costs of equipment and personnel lost indicates that the attack supported by the VHLH costs only 60% of a standard attack. In calculating the cost of an attack, U.S. Army doctrine assumes that 80% of damaged equipment (including helicopters) can be recovered and repaired (see Tables 13 & 14). It is assumed (Table 14 b) that disabled helicopters are 80% recoverable, cost wise. A pessimistic estimate would be that they are a total loss. This would add $25 X .8 X 100,000,000 or $2 billion to the battlefield cost with the VHLH, bringing the cost of the attack to $5.99 billion. This still results in a 9% cost savings over the attack without the VHLH. If this estimate were to be used, the recovered value of the other equipment should also be nullified.

Despite this cost savings, cost is not the key point. Such a fiscally based analysis does not reflect the more important intangible human effects of high casualties on the morale, operational tempo, and momentum of an attack. It is rather the swiftness of the breakthrough, the operational flexibility and the conservation of combat power that will give U.S. commanders the ability to dominate their opponents on the modern battlefield.

There are currently three heavy-lift helicopters in production worldwide (Figure 5 from Ref. 35); in the U.S., the CH-47 Chinook, made by Boeing Vertol, and the CH-53 Super Stallion, made by Sikorsky; and in Russia, the Mi-26, made by MIL Moscow Helicopter Plant.

A historical sketch of aircraft size growth trends, extending twenty-five years into the future is shown on Figure 6 which is an extension of figure 19 of Ref 36. It shows both fixed-wing aircraft and helicopters. It can be seen that the trends for aircraft and helicopters are similar, with the helicopter’s lagging 20 to 50 years. In order to obtain realistic long-term trend curves on both aircraft and helicopters, reliance was placed on published data. As far as the helicopter is concerned, the Central Aerohydrodynamic Institute - Russia, TsAGI presented a paper in 1993 showing a "proposed Superheavy Jet Crane Helicopter," with a payload of 250 tons (fig. 8 of Ref. 37). In plotting Figure 6, it was assumed that this would correspond to a gross weight of 500 tons. It was further assumed that such an aircraft would come to fruition in the time frame between 2020 and 2040 hence the "spread" on Figure 5. In the same paper, TsAGI is proposing (fig. 4 of Ref. 37) an "aircraft with undercarry monocargo of 500 tons arranged stores." This design is plotted as the upper design point in Figure 6, and shows a "growth" curve which is compatible with the AN-225, an aircraft which is currently flying. Also shown on Figure 6 is a point representing the VHLH of this paper. It can be seen that even if wide variations are assumed about the potential introduction of the TsAGI 250-ton helicopter, the VHLH proposed in this paper fits the longer-range predictions.

The helicopter configurations, past and projected, shown on Figure 6, are also shown in Figure 7, which is an extension of figure 19 of Ref. 36, in terms of the relative size of the aircraft. Shown in particular is a proposed Boeing Vertol 75-ton payload tandem-rotor helicopter. This is a helicopter slightly larger than the VHLH of this paper. It is interesting to note that each rotor of the 75-ton design is only slightly bigger than that of the single rotor XH-17, which first flew in 1952, 44 years ago.

Finally, Figure 8 (reproduced from Ref. 38) is included to present a global view of the weight-payload relationship for the aircraft shown on Figure 6. A figure like this must be interpreted cautiously, because the "design point" for each aircraft is not specified. For example, because all aircraft are referenced to a 4000-km

FIGURE 5 HEAVY LIFT HELICOPTERS IN PRODUCTION (1996) (REF. 35)

range which is much in excess of the range for the VHLH, and to a varying technology date, it is expected that the payload to gross weight ratio of the VHLH will not follow the "30% or 40% GW" payload to gross weight ratio, but a 50% curve.

The technology of Heavy Lift Helicopters (HLH) goes back fifty years and can be conveniently divided into two types of configurations:

- Conventional configurations characterized by a drive train consisting of: engine, mechanical geared transmission, and rotor.

- Unconventional configurations: hot cycle(XH-17), cold cycle (a small early example was the French Djinn) and warm-cycle rotors (the Hughes follow-on of the XH-17), see Ref. 39.

The second type of configuration was dominated by the goal to eliminate mechanical rotor drives. The most audacious VHLH proposal today, by TsAGI, involves a tip jet propulsion helicopter (with a 250-ton payload) with five turbo fan engines (Figures 6 & 7).

In this paper, the decision was made at the outset not to get bogged down in a controversial discussion about the VHLH configuration (number of rotors: see, for example, Figure 3 of Ref. 39, or types of propulsion systems as are discussed for example, throughout Ref. 39). The baseline configuration which was chosen (shown below as Figure 11) is a larger version of the XCH-62A (Figure 7) and is also similar to the proposed 75-ton payload helicopter, also shown on Figure 7.

3-view of Schneck-modified Super VHLH

VHLH with FCS underneath

Super VHLH with M1 Abrams tank underneath

VHLH side-view with M1 Abrams MBT

The discussion of the technology background in this section is therefore restricted to the conventional twin-rotor tandem configuration. The detailed technology of Russian work on heavy lift is not available to U.S. and is therefore mentioned in very general terms in this paper.

The major work on HLH technology development in the U.S. has been performed by ATCOM and its predecessor organizations, usually through contracts with the helicopter industry, mostly Boeing Vertol, Sikorsky and McDonnell Douglas. A few typical references are shown at the end of this paper.

One may distinguish three phases of development:

1. In the mid-1960's, the U.S. Army initiated design studies for an HLH, which led to the HLH Advanced Technology Component (ATC) program. The objective of the program was to provide the technology base for an HLH configuration with a payload capacity up to 35 tons and to achieve a maximum reduction in cost and risk (Ref. 36). This led to the design of the XCH-62A helicopter, a prototype of which was initiated to serve as a flying test bed for the ATC components. The program was terminated in 1975 by the U.S. Congress on the basis of affordability issues. The program is well summarized in References 36, 39, 40, and 41.

2. "NASA, in 1978, formed a technical team composed of NASA, Army and Navy representatives to perform a preliminary assessment of large cargo and transport rotorcraft technology needs, potential benefits and research program options (Ref. 36). The team’s funding reaffirmed the potential civil and military applications for heavy lift and put forth recommendations for a comprehensive research program." (Ref. 36)

The Army developed a draft Operational and Organizational (O&O) Plan for an Advanced Cargo Aircraft (ACA) in May 1986 and updated it in January 1987. The program is described in References 42 to 46. Technical efforts from Sikorsky are described in Ref. 43 and 44, from VECTOR and Boeing Vertol in Ref. 45. A program overview is presented in Ref. 46. References 43, 44, and 45 represent today’s state-of-the-art, including technology projections for the near-term future. The result of the VECTOR and Boeing studies form the basis for the design study of this paper. There is no current follow-up of the ACA project.

3. In the period 1995-1996, there is little activity as regards the HLH. There are no further U.S. purchases of the CH-47 or proposed development of an enlarged version. However, the Army intends to upgrade about 300 CH-47s to an Improved Cargo Helicopter (IHC) configuration. DOD has formulated a "Rotary Wing Technology Development Approach" (TDA, Ref. 47). The TDA (the first report was published in 1995) "defines four technology areas, including aeromechanics, flight controls, subsystems and structures, each of which is linked to year 2000 and 2005 objectives." Assuming the TDA’s objectives are met, a cargo/transport rotorcraft would achieve a series of goals, such as a 72% range increase (or a 60% increase in payload), a 20% increase in reliability, a 10% improvement in maintainability, and a 15% reduction in procurement costs.

The VHLH design proposed in this paper, with a payload of 70 tons, though correct in accordance with historical trends (Figures 6 & 8) is not currently under consideration in the U.S.. The earlier XCH-62A, with a 35-ton payload, was canceled for being "unaffordable". Currently, the payload of the CH-47 is only 14 tons. There must be very strong considerations to justify a four-fold increase in payload, in a single jump. There has been agreement for twenty years among the technical community that a 75-ton payload helicopter was feasible. What has been missing was a strong, in fact, compelling mission. Such a mission is presented in this paper.

Sizing of a VHLH is driven by the weight of the payload, which, in our case, is determined by the results of the operational analysis reported above. The rationale for the final choice of a 70-ton payload is described below.

In the past, payload sizing of a utility/cargo helicopter was chosen as a result of "transportation" analyses, such as: design a system with the lowest life cycle cost that will transport so many ton-miles of military supplies per day under specified conditions. Because items to be transported were grouped toward the bottom end of the weight scale, results were most of the time that bigness of a helicopter design did not make economic sense and took too long to develop. It was more efficient to dismantle the biggest loads and select a lower weight option. As a result, the largest U.S. Army helicopter today has a payload around 14 tons.

In the study reported here, a different approach was taken. The need for a VHLH capable of transporting the M1 MBT in support of a vertical envelopment, thus giving the tank three-dimensional mobility, was examined as a sole criterion.

In order to respect tradition, size of the VHLH payload was only determined after studying four options, in terms of increasing payload.

First, one can take four 15-ton payload helicopters and couple them in some fashion to lift a single payload, in this case a 60-ton payload. This approach has been proposed and even demonstrated many times in the past, but it is not currently reckoned in our view because of operational problems, in a battlefield environment, at night and under all-weather conditions. use of a lighter-than-air platform presents even greater problems. However, this is the minimum cost option.

Second, design and field an HLH-32 (the 32 number stands for the payload weight, in tons). This would enable the Army to deploy a lightly armored airmobile task force built around the M-2/3 Bradley, and the M-109A6 howitzer. The new M8 Armored Gun System, weighing up to 25 tons and planned for fielding to the Airborne/Air Assault/Light Divisions has been terminated due to budget constraints (Ref. 47, page 6). However, with the demise of the AGS, this force lacks adequate anti-armor firepower (Ref. 48, page 14 and Ref. 49, page 23). Thus, this organization lacks the staying power of the standard armored/mechanized task force. It would fight at a severe disadvantage against a conventional opponent if it were brought into a pitched battle. Its utility in the reinforcing and counterattack rolls would also be severely restricted. The VHLH-32 would also be less capable of providing logistic support. Furthermore, this organization would lack mobility equipment (Armored Vehicle Launched Bridge, Battalion Countermine Set, etc.) thus limiting its tactical flexibility. The lack of such critical flexibility was one of the key reasons for the German’s defeat during the Battle of the Bulge where the lack of effective bridging and countermine equipment was critical to their inability to advance, particularly for the main effort of the 6th SS Panzer Army spearheaded by Kampfgruppe Peiper (Ref. 50).

Third, design and field a VHLH-65, with the ability to move the M1A1 main battle tank 100 miles without refueling. This would enable the Army to deploy most of the equipment found in a standard armored/mechanized task force. The heavier M1A2 as well as some of the heavier/more specialized equipment such as the armored recovery vehicle, the M-1 Breacher and countermine equipped tanks would require refueling to reach the desired range of 100 nautical miles. The disadvantages are that the M1A1 constitutes approximately half the U.S. Army tank fleet, thus restricting the range of operations possible with the other (M1A2) half our current tank fleet.

This option has the advantage that it meets most of the desired performance objectives at a lower cost and schedule risk than a larger option.

Fourth, design and field a VHLH-70, which will carry the M1A2 Main Battle Tank under all battlefield conditions. The war gaming presented above uses that option, which is shown to be attractive. It is the option retained here.

Because of the incertitude of future specific requirements, the VHLH discussed below is a baseline configuration, which could apply as well to the VHLH-60 or the VHLH-75. It would be unwise to stretch it beyond 75 tons, using current technological limits.

The reason for the design study of this paper is not to present a detailed engineering analysis of a proposed VHLH. It is to support the operational analysis of the previous section by describing the characteristics of a VHLH which will carry out the mission outlined above. Specifically, it is to establish that a helicopter with a 70-ton payload, four times as large as anything in the U.S. Army inventory today, is feasible and affordable in the near term. If this were not the case, all the arguments presented earlier about the increased mobility for heavy armor in the 21st century would be moot.

The mission to which the VHLH must be designed is still very fluid. However, it is initiated on the basis of a mission payload of 70-ton (140,000 lb.), a radius of 100n.mi., with a minimum hover capability at 2000 ft/70^o F, with the hoped for 4000 ft/95 ^o F goal. The vehicle must be rugged and incorporate today’s technology, day-night, all-weather capability and full integration into the "digital battlefield." It must be austere and need not have a forward speed in excess of 100 knots.

The technology background for the study is today’s and the early tomorrow’s state-of-the-art. This technology was summarily described and referenced earlier in the paper. It emphasizes U.S. technology and, maybe unfairly, slights Russian and Ukrainian technology, because we know little about it, except for its many demonstrated hardware accomplishments. The technology used here combines the results of government efforts, mostly those of the Army’s AATD and of their contractors: Boeing Vertol, McDonnell Douglas (the successors to the Hughes Heavy Lift Technology) and Sikorsky, and of their subcontractors. Whenever possible, the analysis below relies on published rather than just in-house information.

The VHLH model proposed here is a "baseline" configuration, which had to be arbitrarily selected. It embodies a tandem rotor rather than a single-rotor configuration. The Russians once pioneered the side-by-side configuration (similar to the V-22) but it was felt that the information on very large systems of this type was missing. A multi-rotor configuration (Ref. 38) presented equal uncertainties. Also, though many people have felt for a long time that the mechanical transmission, a main element of all flying helicopters today, was a hindrance to the development of large helicopters; it was concluded that there is no mature technology today for unconventional powering systems and a conventional transmission is retained here.

In other terms, the configuration proposed here is a straightforward "scaling-up" of the Boeing Vertol XCH-62A, using, however, the advanced technology developed in the last twenty-five years.

Because it is their traditional expertise, the contribution of Boeing Vertol is preeminent: as early as 1979, their engineers were willing to envision helicopters with payloads of 75 tons and gross weights of 300,000 pounds, as enlarged versions of the XCH-62A prototype which they had conceived and developed (Ref. 36).

The starting point of this discussion is therefore the presentation in Table 16 of the design for a heavy lift-logging helicopter with a 75-ton payload, suggested in Ref. 36. It is based on a Boeing Vertol estimate of a gross weight-payload relationship for "large tandem helicopters possible for the future" (figure 18 of Ref. 36 and Figure 9 of this paper).

Also shown on Table 16 is a list of characteristics of a scaled down 70-ton payload-logging helicopter and of the proposed 70-ton VHLH.

It should be noted that the VHLH, for the same payload, is conservatively sized to a higher gross weight than the logging helicopter.

It is felt that the gross weight of the 70-ton payload Vertol logging HLH is optimistic and it was increased by five percent for the VHLH on account of "military" requirements (self-sealing fuel tanks, ballistic protection, etc.). Should the gross weight of the VHLH increase further because of additional mission requirements, this would not affect the feasibility of the proposed design, up to a gross weight of 300,000 lb.

If one were to follow past predictions of weight trends for helicopters, for example, Ref. 53, published in 1969, and its update published in 1990 (Ref. 54), one would use less optimistic weight figures than those shown on Table 16 for the VHLH. However, for example, the chosen figures reflect the fact that, by limiting the speed of the VHLH to 100 knots, instead of the expected 150 knots plus, one can achieve a gross weight reduction, as shown in Figure 10, borrowed from Ref. 54. One of the main reasons is the reduction in transmission weight resulting from the ability to have a higher rotor speed.

In Table 16, the ratio of payload weight to gross weight is taken as 53.8 percent. The commonly accepted figure today is 50 percent. A sixty- percent fraction for the useful load (payload plus fuel) is also acceptable. From an extrapolated plot of the empty weight to payload ratio against payload, obtained from Ref. 45, for a 70-ton payload, a value of 0.74 is found, which is exactly the value used for the VHLH in Table 16. Again, should one find the weight data of Table 16 too optimistic, the choice of a gross weight of 280,000 pounds would remove all objections, but it is felt that 260,000 pounds is an achievable goal. There is no space here to discuss in detail the weight reductions achievable with near term technology advances, but they have been identified as part of the ACA program, as reported, for example, in References 44 and 45. Finally, it is generally accepted that, for very large sizes, tandem configurations are lighter than single rotor configurations.

Sizing of the rotor for the VHLH can be quickly obtained from Figure 9. For the 70-ton payload, a rotor diameter of 110 ft is found. It was decided to use a rotor diameter of 120 ft, to keep the disc loading at 12 pounds per square foot.

A sketch of the proposed VHLH baseline configuration (an enlarged XCH-62A) is shown in Figure 11.

e general features of the design are:

-Tandem rotor configuration

-4 engines, 2 forward, 2 aft, with cross shafting

Candidate engines would be slightly up rated Ukrainian ZMBK D-136, now with a maximum contingency power of 11,400 shp, with a maximum take-off power of 10,000 shp and a specific fuel consumption of 0.456 lb/hr/shp

-Transmission rating: 24,000 shp

-Fuselage as shown in Figure 11, with the M1 tank underslung or with a pod

-Fixed landing gear

-Conventional advanced rotor system (similar to Boeing Vertol Helicopter)

-Advanced cockpit, fully integrated into the digital battlefield

-Self-sealing fuel tanks

-Modular armor for pilot & drive system protection with 23mm protection

-In-flight refueling

-Defensive armament

-Surface-to-air missile countermeasures

An estimate of the risk involved in a new design such as the proposed VHLH is essential in order to estimate the cost and development schedule. The approach is taken in this paper that, inspite of its very large size, the VHLH is within the near-term state-of-the-art, requires no technological breakthroughs, because it can benefit from the technological advances of the past twenty years.

The historical review of the VHLH indicated that, in terms of size and weight, it is well within the envelope of today’s structural design. Its fuselage is no bigger than that of a medium-size commercial jet transport. The rotor diameter of 120 ft is also within the tractable range. It is only 14 percent larger than that of the Russian Mil Mi-26.

If one looks at the VHLH as an enlarged Mi-26, in a tandem configuration, one finds that a twin rotor Mi-26 would lift 246,000 lb., against 260,000 lb. for the VHLH and that the Mi-26 transmission, at 22,000 hp, is not much smaller than that required for each rotor of the VHLH; one only needs to add the cross-shafting.

For those who have studied and seen Russian fixed-wing and rotary-wing very large aircraft, the conclusion is reached that size, by itself, is not a major problem; the Russians developed large aircraft because they needed them. The U.S. could have done the same, and still can.

Specifically, it is proposed to use the rotor system pioneered by the Boeing Vertol 360 helicopter (a four-bladed rotor system) which is to be incorporated into the CH-47 Follow-on or CH-47 FO and later the Improved Cargo Helicopter (ICH) (Ref. 56), as well as the ICH’s fully integrated avionics, which will tie the aircraft together with other Army’s Conceptual Force XXI elements by digital communications. Since the ICH program is most likely to move forward, it will pay for the avionics developments required by Force XXI; its adaptation to the VHLH will therefore be relatively inexpensive.

As far as the structural design of the VHLH is concerned, it is entirely state-of-the-art. The landing gear, being fixed, is straightforward; no matter what payload configuration is eventually chosen.

As was recognized fifteen years ago (Ref. 36), the major problem area is the power system. As far as engines are concerned, there is not today in the U.S., a 10,000 to 15,000 hp turbo shaft engine in production. However, U.S.-made gas generators, now used in the turbofan mode, could easily be modified to a turbo shaft configuration. In the meantime, the Ukrainian engine company, Zaporozhye Machine Building, Design Bureau Progress, has produced, in addition to the D-136 engine for the Mi-26 (10,000 shp), the engine for the YAK-46, with a take-off rating of 13,880 hp and the D-127 engine with a takeoff rating of 14,000shp.

The major problem is the transmission. There is no 24,000 hp transmission available today in the western world. However, the Mi-26 has a transmission driven by two 10,000 shp D-136 engines. The transmission problem is excellently described in Ref. 36 and is in no way insurmountable. Caution must be exercised that the Russians are very good at large engined/transmissions, but that those are very heavy. This is one of the reasons why, in this paper, a ten to fifteen percent "reserve" on gross weight has been provided.

As stated earlier, non-mechanical transmissions have been studied earlier, but that approach involves considerable development risks, which would detract from the philosophy of the proposed VHLH.

In conclusion, in the scale of state-of-the-art demonstration projects, from low technology, medium technology, high technology, major technology (stealth), we place the VHLH at the very low end of medium technology.

The Army ACA studies of the late 1980s have produced the most recent and exhaustive set of data on the "cost trend" of very large helicopters (Sikorsky study, Ref. 44 and Vector-Boeing study Ref. 45). The key cost figure for the VHLH of this paper is the unit production cost of the 70-ton payload aircraft, because this is the number which is critically needed for the cost analysis shown in Table 15. However, one is also interested in an estimate of the life-cycle cost and of the development cost.

There are a few additional published reports on Helicopter Aircraft Systems Costs, such as Ref. 55.

The production cost of a helicopter is traditionally estimated on the basis of empty weight. In the design section of this report, the VHLH empty weight was estimated to be 103,000 lbs., which is therefore used here.

Cost estimates which were contemplated ranged between $750 and $1,500 per pound. It was decided, at the end, to use the low end of the estimate, e.g., $750 per pound (in 1979 dollars), because, as emphasized earlier, the proposed VHLH is a completely conventional configuration, with no risky features and strictly off-the-shelf technology. On that basis, the unit cost of the VHLH is estimated at 92 million dollars, which adjusted for inflation, amounts to 100 million dollars per aircraft.

As a point of comparison, according to the Washington Post of 1 June 1996, "McDonnell Douglas and United Technologies have completed contracts with the Air Force to provide eighty C-17 aircraft for $16.2 billion." This amounts to $202.5 million per aircraft. For an empty weight of the C-17 of 269,000 pounds, this amounts to $753 per pound of empty weight. Delivery of the aircraft will span seven years; therefore, potential inflation is factored into the cost.

A correlation between the estimated unit cost above ($750 per pound of empty weight) and the ACA program’s estimates (Ref 44 and 45) and worked out surprisingly well. Figure 12 is a reproduction of figure 75 of Ref. 45. The lower curve shows the unit production cost of an HLH against empty weight. The upper curve shows the life cycle cost of an aircraft.

The production cost is seen to be $93.312 million, which adjusted for inflation, amounts to about $100 million. The life cycle cost per aircraft is about $130 million.

The validation of the data of Figure 12 is further supported through table 40 of Ref. 45, which is reproduced here as Table 17. It shows the correlated data with regression equations used to establish figure 12. Note that the numbers shown on Table 17are total costs for 472 aircraft.

In conclusion, a figure of 100 million dollars per aircraft is assumed for the VHLH. This figure is used in the battlefield casualty cost analysis shown in Table 15. It is essential to notice that, in accordance with Army doctrine, it is assumed in Table 15 that 80% of the value of the "lost" items of equipment can be recovered. This

1. Recurring production: (1989 $millions)=(472 aircraft) X (5.74+ .000823 X Empty weight (lbs.))

2. LCC: (1989 $ millions)=(472 aircraft) X (24.55 + .001 X Empty weight (lbs.))

may appear overly optimistic, but for consistency, the same proportion is used for the VHLH.

A development cost of the VHLH-70 could not be found in the ACA studies and therefore, was developed independently.

Such a cost is most realistically obtained by collecting, over many years, the development costs of all major military (aircraft) systems and summarizing them into a single plot. As for unit costs, the major parameter is (then year) cost of development per pound of empty weight, this must be corrected for inflation and the creeping reality that development costs keep increasing year after year, probably as a result of increased technological complexity. Finally, costs must be graded in terms of "technology complexity," from the demonstration prototype to the most complex one (the stealth aircraft, for example. The difference in cost between simple and exotic projects is staggering: it is as much as a factor of 1000 to 1.)

In the earlier section on VHLH design risk assessment, it was proposed that the VHLH development be aimed to be in the low end of medium technology.

One can fix the time frame of a VHLH program by situating it in the first years of the 21st century. using a state-of-the-art chart of development cost (in dollars per pound of empty weight against calendar year) one comes up with a development cost of $30,000 per pound, which would not be likely to escalate beyond $50,000 per pound. This translates to a development cost of three billion dollars, never to exceed five billion dollars. The VHLH program should be austere and take full advantage of the cost reduction technologies that are currently very fashionable: computer-aided design and Total Quality Management, for example.

What a three to five billion dollar development cost suggests, however, is the need for a sizable production run to make the aircraft affordable; a run limited to thirty aircraft would double the unit cost for example.

There is an optimistic answer to the above question. While the case was made here for the VHLH based on its decisive contribution to the battlefield of the future, a case of sufficient import to get a program started, it is quite clear that, should the aircraft be developed there is a multitude of eager potential users, as discussed further. A 400 aircraft minimum production run seems, therefore, conservative.

On an increasingly lethal battlefield, one may question the ability of such a large target as the VHLH to survive. There is a growing trend not to expose the most expensive assets to close combat conditions. The trend, not long ago, to have the C-130 or C-17, land in the middle of the battlefield to resupply ground troops, as soon as a landing has been secured, seems to be revised. There is also a goal to replace manned surveillance aircraft with unmanned vehicles, whenever technology will permit.

The threats to which a VHLH will be exposed are detailed in the first part of this paper. The remedy is also discussed: it is combined arms integration, in a digital battlefield. In discussions with colleagues during the preparation of this paper, the authors were surprised to note that generally speaking, vulnerability was not at the top of the list of obstacles to the development of a VHLH (funding was!). The reasons are technological, operational and psychological.

First, in the last twenty years, survivability of helicopters, for example, against small arms fire, has made great progress. It is becoming very difficult to disable a rotor system from the ground. Electrical and hydraulic lines have also been hardened. Active and effective efforts are made in countermeasures, for example, to confuse the guidance systems of ground weapons.

Second, and foremost, the VHLH is only going to be employed in a battlefield situation, as part of an integrated combined arms team, that will protect it from enemy fighter attack and guide it through the dispersed battlefield away from strongly defended areas. Whenever possible, the VHLH will operate at night, as well as under all-weather conditions, at least during an initial attack into enemy territory. The VHLH will share with other combat helicopters the ability to operate nap-of-the-earth. Whether it will carry defensive weapons or not is an issue that has not yet been addressed.

Psychologically, there is a strong push today for warfare with a minimum number of casualties. To propose a VHLH as a troop transport, carrying several hundred people, would be deemed unacceptable. The troops will continue to be moved by utility helicopters and/or the CH-47. There will certainly be casualties: in the war game scenario presented above, a corps loses 25 VHLH after a couple of days (Table 15). But consider the payoff: 4000 less casualties. A VHLH will only carry the aircraft crew (four personnel) and the tank crew (four personnel). Isn’t it, therefore, better to lose material then people?

In today’s political and economic environment, dominated by the downsizing of military forces, at least in the western world, it is expected that there will be very few, if any, new initiatives in the defense industry in the next five years. For example, projected military aircraft sales up to 1998 are shown in Figure 13 (Ref, 57), a decrease of 35 percent between 1991 and 1998. It is therefore reasonable to wonder if the proposal in this paper for a VHLH development is realistic.

The paper was originally conceived as an answer to the stated request in the Force XXI Operations TRADOC Pamphlet 525-5 (Ref. 1) for innovative ideas

FIGURE 13. PROJECTED U.S. MILITARY AIRCRAFT SALES (1990-1998) (Ref. 57)

to help maintain U.S. Army supremacy in potential (undefined) 21st century conflicts. The answer proposed in this paper, the ability to give "three-dimensional" mobility to heavy armor by using a VHLH, appears sound to the authors. Is the mission sufficient to justify the very large expenditures involved? Obviously, it is too earlier to tell, since this is, as far as the authors know, a new concept. However, as an additional support for the development of a VHLH, additional applications of the VHLH are mentioned below, e.g., applications to other services and commercial applications.

A VHLH development program would be of interest to the Marine Corps, as long as they do not have to carry the full burden of it. The ability to carry ashore heavy armor during an amphibious landing, as an alternative to the rather cumbersome LCAC (Landing Craft Air CU.S.hion) is very attractive. The further ability to move vertically the heavy armor inland, as needed, makes it even more attractive to the Marines, who know that you have won only when you have defeated the enemy and occupy his ground permanently.

As far as the U.S. Navy is concerned, the ability to vertically transship large loads (full-size 40-ft containers, for example) will enhance vertical replenishment.

On the commercial side, a VHLH is badly needed for a number of applications. As indicated earlier in the paper, the Russians have developed the largest operational largest HLH (the Mil Mi-26) as much under commercial as under military pressures. They are currently vigorously pursuing commercial applications,

FIGURE 14. COMMERCIAL APPLICATIONS OF RU.S.SIAN HLHs (Ref. 58)

at home as well as overseas (Ref. 57). Recent action shots of their two largest helicopters: the Mi-10 and the Mi-26 are shown in Figure 14 (Ref. 58).

The ability to extend the lifting capabilities of a crane helicopter from 22 tons (the Mi-26 today) to 60 or 70 tons will open up the commercial market tremendously. As early as 1979, Boeing Vertol showed (Ref. 36) that the logging industry by itself would partially support the development of a 75-ton payload helicopter.

If one were assured of a market, military and commercial for a VHLH, what is the sensible way to proceed?

Let U.S. start by using an analogy, that of the development of the very large fixed-wing aircraft (say two million pound gross weight). Philippe Poisson-Quinton, the most senior adviser to ONERA, the Armed Forces and the Aerospace Industry of the French Republic, recently advocated (Ref. 59) an international program for the development of a very large fixed-wing "strategic cargo" transport and has predicted an early market (year 2000 time frame) of 100 units.

In a similar fashion, one could envision an international program, which would primarily include major U.S. helicopter manufacturers, such as Boeing Vertol, McDonnell Douglas and Sikorsky with the Russian developers of large helicopters such as Mikoyan. The division of responsibilities is obvious: the U.S. concentrates on the military version, Russians on the commercial versions. The airframe is what they have in common, until further notice, the Army Force XXI Operations Concept is totally outside their sphere of interest. Therefore, the U.S. handles all avionics. The Russians concentrate on power plant and transmission, and the U.S. does most of the rest. Even for the transmission, the U.S. industry might make useful contributions in reducing its weight.

To propose an international program is nothing really new: the Boeing 777 program has worldwide suppliers. It uses everyone’s best talents, it spreads the economic risk and eventually, it enlarges the total market.

To "prime the pump" an interest from the U.S. Department of Defense is essential.

This paper was initiated in a university environment as an "academic exercise." As it developed, there were indications that its theme might have real world-world immediate implications. Therefore, it was submitted for presentation (and accepted) at the 52nd A.H.S. Forum, in the hope of eliciting reactions from the helicopter community, either positive or negative. Complacency in continuing evolutionary development programs must be challenged once in a while.

The paper is two papers in one:

First, it is an analysis of what the Army could do in response to the Army’s Force XXI Operations Concept. It could increase its mobility over a geographically expanded battlefield. For fifty years, the mechanized Army has tried to achieve "off-the-road" mobility, with limited success (the M561 Gama-Goat could never emulate the goat). When told that vertical mobility of all Army assets (including heavy armor) now ground limited, could be achieved with an HLH, several combat arms officers were excited. They ran a limited war game that demonstrated great promise of the VHLH.

Second, the helicopter designer reviews the field of heavy lift helicopters and comes to the conclusion that a 70-ton payload fairly conventional helicopter, which requires no breakthroughs, is feasible in a near time frame (ten years or less). Its unit cost is estimated at $100 million per unit, development cost around $3 billion. Additionally, it is estimated that there are many other applications, both military and commercial, for the VHLH, that can reduce development and commercial costs significantly.

When the two above "papers" are put together, the Army war game is run again with the $100 million cost of the VHLH included as well as without the VHLH. The numerical answer proves the VHLH cost effective. In addition, it allows the Army to win the battle in a much shorter time.

The authors of this paper therefore conclude that the VHLH is a timely development. A last remark is made below.

The proposed development of a VHLH does not step on anyone’s toes, by compromising existing programs.

The Air force is still needed to insure air superiority (the worst enemy of the VHLH is the supersonic fighter) and provide ground support and large area reconnaissance.

The attack/scout helicopter is essential as an escort to the VHLH, to identify enemy concentrations so it can avoid them and to protect the VHLH from the threat of enemy attack helicopters.

The utility helicopter is still needed to transport troops and to resupply them.

For a national defense strategy to be realistic, it must be executable at the operational and tactical levels. The small U.S. Army of only ten active duty divisions could cover a linear frontage of only about 250-km. If such a small army is to be able to execute its strategic requirement to fight and win two nearly simultaneous. MRCs, it is essential to win quickly. U.S. stocks of advanced munitions, weapon systems and highly trained personnel are extremely limited Additionally; these cannot be replenished in a timely manner due to a lack of production facilities, strategic sea and air lift, and readily available, highly trained replacements.

U.S. reliance on allied or coalition partners is risky. For this strategy to be reliable, it should be based only on U.S. capabilities while encouraging other nations to assist whenever possible.

In order for the two MRC strategy to be practical with ten divisions, this force will require significantly more combat power than it presently possesses. The political leadership must match their strategic requirements with resources if national strategy is to be more than a piece of paper. There has been some discussion that the two MRC strategy is too ambitious However, anything less would be strategically unstable becaU.S.e it would encourage any two potential opponents to form an alliance against the U.S. and result in a second war if one were to breakout and demand U.S. involvement.

With a full understanding of the situation stated above, General Gordon R. Sullivan, as the Chief of Staff, United States Army, in an introduction to the "Force XXI Operations" pamphlet (1 August 1994), issued a call to government, industry and academia for innovative thoughts ("using their collective experience, intelligence, energy and willingness to engage with the world of the future"). This paper is a modest response to that call, which focuses on increased mobility and the element of surprise. In summary, our conclusion is that the development and fielding of a Very Heavy Lift Helicopter capable of transporting the M1 MBT 100 nautical miles from the point of embarkation would provide a significant, possibly decisive, operational advantage over the potential adversaries of the U.S. on the conventional battlefield. Such an aircraft is well within the state-of-the-art capabilities for today's aerospace industry. The U.S. Department of Defense should design and field the VHLH.

The following recommendations are made: First, since there is within DOD a committee tasked with preparing a road map for rotary-wing development in the near-term and mid-term future (the group charged with RWV/TDA, or Rotary Wing Vehicle/Technological Development Approaches), it is suggested that this group include the VHLH in its debates, focusing on what may not have been addressed before, for example the development of a 25,000 HP power module, especially the transmission part of it.

Second, the war gaming presented in the paper is very crude and could usefully be refined, using full-scale war gaming facilities.

Third, the desirability of maintaining battlefield dominance by the U.S. Army in the XXI century through a tank helicopter weapons system, in addition to the current philosophy of attack helicopters/limited capacity cargo helicopters should be addressed.

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ALTERNATIVES

There are three possible approaches to more fully develop the ability of the U.S. to execute decisive vertical envelopments. These are discussed below:

1) The U.S. Army could design and field a VHLH-72 (72 denotes the design payload capacity in tons) designed for the M1A2 main battle tank.

Disadvantages: Either a new turbo shaft engine with a rated capacity of about 15,000 shp would have to be developed to accommodate the worst case load or six off-the-shelf engines would have to be used. The technical, cost and schedule risk would be significantly greater than that for the VHLH-65 for a comparatively small operational payoff.

Advantage: It would meet the ideal performance specifications.

2) The U.S. Army could design and field a VHLH-65

3) The U.S. Army could design and field a VHLH-32 designed around the M-109A6 howitzer.

Mechanized/armored forces deployed by helicopter would be particularly vulnerable to artillery and air- delivered scatterable mines if they were not properly equipped with mine breaching equipment.

Scatterable mines are very likely to be used to "fix" a helicopter-inserted force until reserves can be deployed against it.

The ability to rapidly breach obstacles is critical against a modern MRD which can remotely lay over 8 km of minefields per day.

Figure 6

OPERATIONAL RISKS

Deep Operations employing ground forces in a vertical envelopment role are vulnerable to being cut off from friendly combat forces and logistic support. This may happen as a result of weather (resupply helicopters become grounded), enemy reinforcement of his air defense assets to disrupt aerial resupply, or the enemy gaining local air parity

MILLIONS $ PER AIRCRAFT (1989$)

O VHLH

O VHLH

Underline indicates air delivery into combat

*Does not include reliable allies such as Canada, Western Europe, Israel, AU.S.tralia, and Japan

NOTE 1) All Russian MANPADS are vulnerable to suppressive fires and obscuration.

2) All current Russian divisional air defense systems are vulnerable to fragmentation.

3) All current Russian divisional air defense radars are vulnerable to ECM.

4) Most echelons above division Russian air defense systems have minimum altitudes in excess of 90m.

*Added weight for countermine equipment, these items would have to be transported separately to the landing zone and assembled there.