Editing Leopard 2 (section)

==== American evaluation of Leopard 2AV and XM1 Abrams ====
In July 1973 German Federal Minister of Defence [[Georg Leber]] and his [[United States of America|US]] counterpart [[James R. Schlesinger]] agreed upon a higher degree of standardisation in main battle tanks being favourable to NATO. By integrating components already fully developed by German companies for the Leopard 2, the costs of the [[M1 Abrams|XM1 Abrams]], U.S. prototype tank developed after the MBT-70, could be reduced. A German commission was sent to the US to evaluate the harmonisation of components between the XM1 and Leopard 2.<ref name="Waffensystem" /> However, under American law it was not possible for a public bidder to interfere in a procurement tender after a contract with intention of profits and deadline was awarded to private sector companies.<ref name="Waffensystem">{{cite book|last1=Krapke|first1=Paul-Werner|title=Das Waffensystem Kampfpanzer Leopard 2|date=1984|publisher=Allgemeine schweizerische Militärzeitschrift<!--|access-date=30 October 2015-->|language=de}}</ref>

[[File:Early Leopard 2 Tank Prototype at Yuma Proving Ground, 1975.jpg|thumb|right|Leopard 2 prototype tested at the Yuma Proving Ground, September 1975]]

As a result, the modification of the Leopard 2 prototypes in order to meet the US Army requirements was investigated. Following a number of further talks, a [[memorandum of understanding]] (MoU) was signed on December 11, 1974, between Germany and the US, which declared that a modified version of the Leopard 2 should be trialed by the US against their XM1 prototypes,<ref name="Krapke32">Krapke, p. 32.</ref> after the Americans had bought and investigated prototype PT07 in 1973.<ref name="Jerchel, p. 8">Jerchel, p. 8.</ref> The MoU obliged the Federal Republic of Germany to send a complete prototype, a hull, a vehicle for ballistic tests and a number of special ballistic parts to the US, where they would be put through US testing procedures for no additional costs.<ref name="Krapke33">Krapke, p. 33.</ref>

The Leopard 2AV (''austere version'') was based on the experiences of the previous Leopard 2 development. It was created in order to meet the US requirements and the latest protection requirements of the German MoD. The T14 mod turret was used as the base for the Leopard 2AV's turret, but meeting the required level of protection for the hull required several attempts until the final ballistic trials on 23 to 26 June 1976.<ref name="Krapke34">Krapke, p. 34.</ref> Following the US' preference of [[laser rangefinder]]s, the turret of prototype PT19 was fitted with a laser rangefinder developed together with the American company [[Hughes Aircraft Company|Hughes]].<ref name="Krapke3738">Krapke, pp. 37 and 38.</ref>

In comparison with the earlier Leopard 2 prototypes, the fire control system was simplified by replacing the EMES-12 optical rangefinder and removing the crosswind sensor, the air pressure and temperature sensors, the powder temperature sensor, the PERI R12 commander sight with IR searchlight, the short-range grenade launcher for use against infantry, the retractable searchlight, the spotlight, the retractable passive night vision sight, the APU and the mechanical loading assistant.<ref name="Krapke33" />

Due to the design and production of the Leopard 2AV taking more time than expected, the shipment to the US and the US evaluation was delayed. It was not possible to test the Leopard 2AV before 1 September 1976.<ref name="Krapke34"/> Despite the German wish that the Leopard 2AV and the XM1 prototypes would be evaluated at the same time, the US Army decided not to wait for the Leopard 2AV and tested the XM1 prototypes from Chrysler and General Motors beforehand.<ref name="Waffensystem" /><ref name="considerations">{{cite book|last1=Staats|first1=Elmer B.|title=Department Of Defense Consideration Of West Germany's Leopard As The Army's New Main Battle Tank|date=1977-11-28|publisher=U.S. Government Accountability Office|location=United States<!--|access-date=30 October 2015-->}}</ref>

Two new prototype hulls and three turrets were shipped to the US: PT20 mounting a {{cvt|105|mm}} rifled [[Royal Ordnance L7|L7]] gun and a Hughes fire control system, PT19 with the same fire control system but able to swap out the gun for the {{cvt|120|mm}} [[Rheinmetall]] smoothbore gun, and the PT21 fitted with the Krupp [[Atlas Elektronik]] EMES-13 fire control system and the {{cvt|120|mm}} Rheinmetall gun.<ref name="Jerchel, p. 8"/> The Leopard 2AV fully met the US requirements.<ref name="Krapke35">Krapke, p. 35.</ref> A study made by the American [[FMC Corporation]] showed that it was possible to produce the Leopard 2AV under licence in America without exceeding the cost limits set by the US Army.<ref name="Krapke35" /> Before the trials were finished, it was decided that instead of the US Army possibly adopting the Leopard 2AV, the focus was shifted to the possibilities of common components between the two tanks. FMC, after having acquired the licenses for the production of the Leopard 2AV, decided not to submit a technical proposal, as they saw little to no chance for the US Army adopting a vehicle not developed in the US.<ref name="considerations" />

The US Army evaluation showed that on the XM1 a larger portion of the tank's surface was covered by special armour (composite armour arrays) than on the Leopard 2AV.<ref name="considerations" /> Differences in armour protection were attributed to the different perceptions of the expected threats and the haste in which the Leopard 2AV was designed to accommodate special armour.<ref name="considerations" /> On mobility trials the Leopard 2AV performed equal to better than the XM1 prototypes. The [[Honeywell AGT1500|AGT-1500]] turbine engine proved to consume about 50% more fuel<ref name="SpiegelSitten" /> and the Diehl tracks had a higher endurance, while the tracks used on the XM1 prototypes failed to meet the Army's requirements.<ref name="Krapke35" /> The heat signature of the MTU diesel engine was much lower.<ref name="SpiegelSitten">{{cite news|title=Orientalische Sitten|url=http://www.spiegel.de/spiegel/print/d-40941854.html|access-date=2015-12-16|publisher=Der Spiegel|date=1977-03-14|language=de|archive-url=https://web.archive.org/web/20160209170007/http://www.spiegel.de/spiegel/print/d-40941854.html|archive-date=2016-02-09|url-status=live}}</ref> The fire control system and the sights of the Leopard 2 were considered to be better and the {{cvt|120|mm}} gun proved to be superior.<ref name="considerations" /> The projected production costs for one XM1 tank were US$728,000 in 1976, and the costs for one Leopard 2AV were US$56,000 higher.<ref name="considerations" />

After the American evaluation of the Leopard 2AV and the US Army's decision to opt for the XM1 Abrams, both American and German sources blamed the other side. US Army test officials discovered that the PT19 Leopard 2AV prototype used for mobility trials did not contain special armour.{{refn|group=nb|name=Kelly|According to the [[United States House Armed Services Subcommittee on Oversight and Investigations|House Armed Services Subcommittee on Armed Services Investigations]], after knocking on the PT19 Leopard 2AV prototype, a hollow sound was heard by Colonel Robert J. Sunell. German Colonel Franz Kettman acknowledged that PT19 was not fitted with any special armor. The American estimated that with the special armour the {{cvt|105|mm}} gun Leopard 2AV would have weighed {{convert|63.2|ST}} instead of {{convert|59.6|ST}}, calling into question the data collected during mobility testing.<ref name="Hollow Tank">{{cite report|author=Investigations Subcommittee of the Committee on Armed Services|title=Hearings on the Status of the Army XM-1 Tank Program|date=1977-10-18|pages=1–12|url=https://books.google.com/books?id=HVCEoh4hys0C&q=test%20rig|access-date=2024-01-09}}</ref>{{sfn|Kelly|1989|p=187-188}}}}

In Germany, the test conditions were criticised for being unrealistic and favouring the XM1. Instead of using actual performance data, the calculated hypothetical acceleration was used.<ref name="SpiegelSitten"/> The XM1 was found to have a slightly higher rate of fire despite having internal layouts similar to the Leopard 2AV because the XM1 prototypes were manned by professional crews, while the Leopard 2AV had to be manned by conscripts in order to prove that the Leopard 2AV was not too complicated.<ref name="SpiegelSitten"/> Firing on the move was demonstrated on flat tracks, which nullified the better [[Gun stabilizer|stabilization systems]] of the Leopard 2AV.<ref name="SpiegelSitten"/>

Germany later withdrew its tank from consideration.{{sfn|Kelly|1989|p=187-188}}