Explanation: The M113's hull is constructed from 5083 aluminum alloy, not steel. This choice of material was deliberate to reduce weight, facilitating air transportability and amphibious capabilities, distinguishing it from heavier steel-armored vehicles.

Explanation: The FMC Corporation, drawing upon its prior development of the M75 and M59 armored vehicles, was responsible for the design and production of the M113.

Explanation: The MICV-65 project aimed to develop a true Infantry Fighting Vehicle (IFV) with enhanced combat capabilities, not solely to increase troop capacity of the existing APC design.

Explanation: The 5083 aluminum alloy was chosen for the M113's hull primarily for its lighter weight, which facilitated air transportability and amphibious operations, rather than for high ballistic resistance. Steel would have offered greater ballistic protection but at a significant weight penalty.

Explanation: The FMC Corporation, a diversified manufacturing company, developed the M113 armored personnel carrier, building on its experience with earlier armored vehicle designs.

Explanation: The M113 was notable for being the first combat vehicle to be mass-produced with an aluminum hull. This material choice significantly reduced its weight compared to steel-armored vehicles.

Explanation: The M113 armored personnel carrier officially entered service with the United States Army in 1960.

Explanation: The original M113 was powered by a Chrysler 75M V8 gasoline engine. Later variants, beginning with the M113A1, transitioned to diesel powerplants.

Explanation: The M113 is designed to be amphibious, capable of swimming using only its tracks and a front trim vane for propulsion and steering, without requiring additional flotation devices. This feature enhances its operational flexibility.

Explanation: The M113's lightweight aluminum hull was a key design feature that enabled it to be transported by tactical air-lift aircraft such as the C-130, fulfilling a critical requirement for rapid global deployment.

Explanation: The standard M113 variant was typically armed with a .50 caliber (12.7 mm) M2 Browning heavy machine gun, operated by the commander. Heavier armament, such as 20mm autocannons, was usually found on specialized variants or later Infantry Fighting Vehicle (IFV) designs.

Explanation: The standard M113 crew typically consists of a driver and a commander (who often operates the weapon). It can carry between 11 to 15 infantry passengers, but the gunner role is usually performed by the commander or another crew member.

Explanation: Rubber band tracks, utilized by some M113 operators, provide several benefits including stealthier operation, reduced wear on paved surfaces, and decreased vibration, contributing to crew comfort and vehicle longevity.

Explanation: The M113's light weight, achieved through its aluminum construction, was a primary advantage that facilitated air transportability and amphibious operations. While it has payload limitations compared to heavier vehicles, its weight was a key design enabler, not inherently a disadvantage for its intended role.

Explanation: The M113 is fundamentally an Armored Personnel Carrier (APC), designed to transport infantry squads into combat zones while providing protection against small arms fire and shell fragments.

Explanation: The primary advantage of the M113's aluminum hull was its significantly reduced weight compared to steel, which enabled air transportability by aircraft like the C-130 and allowed for inherent amphibious capabilities without external flotation aids.

Explanation: The standard M113 variant was typically equipped with a .50 caliber (12.7 mm) M2 Browning heavy machine gun, usually mounted for use by the commander.

Explanation: Rubber band tracks offer advantages such as stealthier operation, reduced vibration, and less damage to roads. Increased armor thickness is not an advantage provided by track type; it relates to hull and armor plating.

Explanation: The M113 has an operational range of approximately 480 kilometers (300 miles) on a full tank of fuel, allowing for considerable operational reach.

Explanation: The M113 has a maximum land speed of approximately 67.6 km/h (42.0 mph), allowing it to keep pace with other vehicles on various terrains.

Explanation: The M577 variant serves as a command post carrier. The M106 variant is equipped as a mortar carrier, typically armed with a 106.7 mm mortar.

Explanation: The M163 Vulcan Air Defense System (VADS) is a self-propelled anti-aircraft variant of the M113 chassis, armed with an M61 Vulcan 20 mm rotary cannon.

Explanation: The Armored Cavalry Assault Vehicle (ACAV) modification kit for the M113 included enhancements such as shields for weapon positions, a turret, and additional steel 'belly armor' to improve crew survivability, particularly in combat zones like Vietnam.

Explanation: The M901 Improved TOW Vehicle (ITV) is a specialized variant of the M113 chassis equipped with a launcher system for TOW anti-tank guided missiles, specifically designed for anti-armor combat.

Explanation: The M548 is an unarmored cargo carrier variant of the M113 chassis, designed for transporting supplies and equipment, rather than serving as an armored personnel carrier.

Explanation: The M113A3 Opposing Forces, Surrogate Vehicle (OSV) variants are specifically modified and visually disguised to represent enemy armored vehicles, such as Soviet-era tanks and IFVs, providing realistic targets for troops during combat training exercises.

Explanation: The Armored Cavalry Assault Vehicle (ACAV) was a modification of the M113 that incorporated additional armor plating, including 'belly armor,' and shielded weapon stations to enhance crew protection during combat operations in Vietnam.

Explanation: The M106 variant is a mortar carrier, typically equipped with a 106.7 mm (4.2-inch) mortar, allowing it to provide indirect fire support.

Explanation: The M577 variant is designed as a mobile command post, featuring enhanced communications equipment and space for command staff to operate from the battlefield.

Explanation: The M163 VADS (Vulcan Air Defense System) is an M113-based variant equipped with a 20 mm rotary cannon, specifically designed to provide mobile anti-aircraft defense against low-flying aerial threats.

Explanation: The M901 Improved TOW Vehicle (ITV) is equipped with a launcher system for TOW (Tube-launched, Optically tracked, Wire-guided) anti-tank guided missiles, making it a dedicated anti-armor platform.

Explanation: The M113A3 OSV (Opposing Forces, Surrogate Vehicle) variants are visually modified to represent enemy armored vehicles, such as Soviet-era tanks and IFVs, providing realistic targets for troops during combat training exercises.

Explanation: The M548 is an unarmored variant based on the M113 chassis, primarily utilized as a cargo carrier for transporting supplies, ammunition, and equipment.

Explanation: The M113 was first utilized in combat operations in April 1962, when it was provided to the South Vietnamese Army as part of the U.S. Military Assistance Command, Vietnam (MACV) program.

Explanation: The M113A1 was a significant upgrade that replaced the original gasoline engine with a more reliable and fuel-efficient Detroit Diesel 6V53 engine.

Explanation: The M113A2 incorporated several improvements over the M113A1, including enhanced engine cooling through radiator and fan relocation, and the use of higher-strength torsion bars for improved suspension and ground clearance.

Explanation: A key survivability upgrade in the M113A3 variant was the addition of external armored fuel tanks, which moved a potential fire hazard outside the crew compartment and also freed up internal space.

Explanation: The original M113 was powered by a gasoline engine, while the M113A1 introduced a diesel engine. The M113A3 variant received a significantly upgraded, more powerful turbocharged diesel engine (Detroit Diesel 6V-53T).

Explanation: The M113's first combat deployment occurred in South Vietnam in April 1962, where it was used by the Army of the Republic of Vietnam (ARVN).

Explanation: The M113A2 incorporated an improved engine cooling system and higher-strength torsion bars, enhancing its reliability and operational performance compared to the M113A1. External fuel tanks and diesel engines were introduced in later variants.

Explanation: The M113A3 variant introduced crucial survivability enhancements, including internal spall liners to protect occupants from fragmentation and external armored fuel tanks to mitigate fire risks, significantly improving crew protection.

Explanation: While the M113 was designed to provide protected transport, its primary role as an Armored Personnel Carrier (APC) focused on infantry mobility rather than direct engagement in heavy combat. Its light armor and design limitations became apparent in later conflicts.

Explanation: The M113's aluminum armor offers protection against small arms fire and shell splinters but is significantly less protective than the advanced steel and composite armor found on modern vehicles such as the Stryker, which are designed to withstand higher caliber threats.

Explanation: During conflicts such as the Yom Kippur War and the 1982 Lebanon War, the M113's relatively light armor proved insufficient against contemporary anti-tank weaponry, leading to significant losses and underscoring its vulnerability.

Explanation: The M113's design prioritized mobility and air transportability through its lightweight aluminum hull, not heavy frontal armor. Its protection was intended against small arms fire and shell splinters, not direct hits from main battle tank cannons.

Explanation: Incidents involving the M113's vulnerability to modern threats, such as the catastrophic losses experienced by the Israel Defense Forces (IDF) in Gaza due to IEDs, significantly highlighted the need for its replacement.

Explanation: Estimates indicate that over 80,000 M113 family vehicles have been produced, and they are utilized by more than 50 countries worldwide, not over 100,000 vehicles in more than 60 countries.

Explanation: M113 production was terminated in 2007, not the late 1990s. While its frontline combat role has diminished, it remained in production for a considerable period.

Explanation: The nickname 'green dragon' was given to the M113 by the South Vietnamese Army (ARVN), not by Australian troops. Other nicknames were used by different national contingents.

Explanation: Estimates indicate that over 80,000 M113 family vehicles have been produced, making it one of the most widely manufactured armored vehicles globally.

Explanation: The M113 family of vehicles is utilized by more than 50 countries worldwide, reflecting its extensive global deployment and long service life.

Explanation: The production of the M113 family of vehicles officially ceased in 2007.

Explanation: The German Army referred to the M113 by several nicknames, including 'Bathtub' (Badewanne), reflecting its distinctive shape and perhaps its amphibious capabilities.

Explanation: While the Bradley Fighting Vehicle has replaced the M113 in many frontline combat roles within the U.S. Army, the M113 continues to be used in various support capacities. Furthermore, the Armored Multi-Purpose Vehicle (AMPV) program is intended to replace the M113 fleet.

Explanation: The Namer and Eitan AFV are modern Israeli armored fighting vehicles developed and fielded to replace the large fleet of M113s operated by the Israel Defense Forces (IDF), addressing the M113's limitations in survivability.

Explanation: The Bradley Fighting Vehicle has largely replaced the M113 in frontline combat roles. However, the Armored Multi-Purpose Vehicle (AMPV) program is specifically designed to replace the M113 fleet in various support roles.

Explanation: The Armored Multi-Purpose Vehicle (AMPV) program is the U.S. Army's initiative to replace the M113 fleet, designed to fulfill multiple mission roles.