In 1967, funded by the U.S. Army, the FMC corporation produced two prototype vehicles designated as XM765 - these were based on their experiences with the earlier XM701 vehicle, developed for the MICV-65 program. The XM765 was based on the M113A1, upgraded with an enclosed turret and firing ports, so that the infantry could fight from within the vehicle. The army evaluated the vehicle, but decided that they wanted a better protected and more mobile vehicle, selecting instead the M2 Bradley.
FMC continued development as a private venture, resulting in the product improved (PI) M113A1 in 1970. The PI M113A1 had the driver and engine at the front, with an enclosed weapon station in the center of the hull and the commander seated at the rear. This arrangement meant that the commander had a very poor forward view. FMC went back to the drawing board and came up with a new design, which had the driver on the front left of the hull and the commander seated behind him. To the right of the commander was a one man turret. The vehicle would later be designated the AIFV (armored infantry fighting vehicle).
While the US was uninterested in the design, a number of other governments were interested in the vehicle, which was simpler, lighter, and cheaper than the Bradley. After a series of demonstrations and the delivery of four evaluation vehicles in 1974, the Netherlands government placed an order for 880 of the vehicles in 1975, which were designated YPR-765 when they entered service. Some changes were made at the request of the Dutch government, including shifting the weapon station to the right side and moving the commander behind the driver. The Netherlands ordered 2,079, of which 815 were produced locally under license. Under the YPR-2000 program, virtually all Dutch vehicles were upgraded to YPR-765A1 standard that is easily identified by the 3-tone NATO camouflage pattern. During the war in Afghanistan, several vehicles were fitted with additional armour.
The Philippines also received 45 vehicles in 1979, these were intended to take 25mm cannons, although some were later modified to fit 12.7mm machine guns.
In 1979, Belgium placed an order for 514 AIFV-B (to be produced locally) along with 525 M113A-B (similar to the M113A2). The first vehicles were delivered in 1982.
Turkey selected the AIFV in 1989, after a competition involving the Alvis Vickers Warrior IFV and United Defense LP Armoured Infantry Fighting Vehicle. The total value of the contract for 1,698 vehicles was US$1.076 billion. The first 285 hulls were produced in Belgium, the remaining vehicles were produced entirely in Turkey. A little way into the production run, with 200 vehicles completed the Turkish AIFV specification was updated to include a more powerful power pack developing 300 horsepower, an Allison X-200-4 transmission and hydrostatic steering from the M113A3. During the production run, a number of changes were made to the armament of the vehicle including different turret packages, and power packs.
The hull of the vehicle is made of welded aluminum, with spaced steel laminate armor bolted onto the side and front. The voids of the armor are filled with polyurethane foam, which gives the vehicle extra buoyancy when travelling in the water.
The engine sits on the front right of the hull, behind a hatch that can used to remove the complete powerpack. The powerpack is similar to the M113A1, except for a larger radiator capacity and turbocharger. The transmission is also fitted with heavy duty components from the M548 tracked cargo carrier. Immediately to the left of the engine is the driver, above whom is a hatch that opens to the right. The driver has four M27 day periscopes. The driver's center periscope can be replaced by a passive infra-red periscope for night driving. The commander sits immediately behind the driver, and has a cupola which can be completely traversed. The cupola has five periscopes, four of which are M17 day periscopes, the fifth has 1x to 6x variable magnification.
The turret is fitted on the right side of the hull behind the engine. The turret has electro-hydraulic traverse and can elevate from -10 to +50° and can traverse and elevate at a speed of 60°/sec. The turret mounts an Oerlikon Contraves 25 mm KBA-B02 cannon with a dual ammunition feed, mounted to the left is a 7.62 mm FN MAG machine gun. 180 rounds of 25 mm are ready to use, with another 144 rounds stored in the hull. The coaxial gun has 230 rounds ready with a further 1,610 stored in the hull.
The troop compartment is at the rear of the hull; a large power operated ramp allows access through the rear of the vehicle, a door is also provided in the ramp. Additionally a single piece hatch covers the top of the troop compartment. The compartment contains seven troops in the Dutch variant, with six sitting back to back facing outwards and a single passenger sitting between the command and the turret facing backwards. There are two firing ports in each side of the hull and a single firing port in the rear. The side firing ports are provided with M17 periscopes, the rear one is fitted with a M27 periscope.
AIFV-B — A revised Dutch variant, fitted with the same suspension as the M113A1-B (similar to the M113A2) and NBC system and Halon fire suppression system; entered service in September 1985. Surplus vehicles have been sold to Chile, with the remaining carriers being phased out in favor of wheeled vehicles.
AIFV-B-C25 with 25 mm KBA-B02 cannon — with smoke grenade launchers fitted on the side of the turret
AIFV-B-MILAN with MILAN anti-tank missile launcher
AIFV-B-.50 with 12.7 mm CWS cuppola, 2 Lyran 71mm mortars and pintle mount for MILAN missile launcher.
AIFV-B-CP — command post vehicle with 12.7mm cupola (M113 type), a tent, generator and telescopic mast.
(the pantser-rups designation means armoured-tracked)
YPR-765 pri (pantser-rups-infanterie) — basic infantry fighting vehicle with 25-mm KBA-B02 cannon and MAG machine gun in turret; crew of three plus seven passengers (normally only five carried); outward-facing bench seats in rear compartment.
YPR-765 pri.50 — armoured personnel carrier with .50-caliber M2 HB machine gun on M113-type cupola in place of turret.
YPR-765 prco-series (pantser-rups-commando)
YPR-765 prco-B — company commander's vehicle with same turret as pri; crew of six plus two passengers; folding table in rear compartment with two inward-facing seats on either side.
YPR-765 prco-C-1— battalion commander's vehicle with .50-caliber M2 HB machine gun on M26 cupola; crew of five plus four passengers; folding table in rear compartment with three-seat bench on left and two seats on right, all facing inward.
YPR-765 prco-C-2 — battalion fire control center with .50-caliber M2 HB machine gun on M26 cupola; crew of seven plus one passenger; rear compartment as for C-1.
YPR-765 prco-C-3 — mortar fire control vehicle with .50-caliber M2 HB machine gun on M26 cupola; crew of four plus one passenger; folding table in rear compartment with two inward-facing seats on left.
YPR-765 prco-C-4 — anti-aircraft command vehicle with .50-caliber M2 HB machine gun on M113-type cupola; crew of five plus two passengers; folding table in rear compartment with inward-facing, three-seat bench on left.
YPR-765 prco-C-5 — observation vehicle for artillery units with .50-caliber M2 HB machine gun on M113-type cupola; crew of five; rear compartment as for C-3.
YPR-765 prrdr (pantser-rups-radar) — radar vehicle fitted with a ZB-298 battlefield surveillance radar, armed with .50-caliber M2 HB machine gun on M113-type cupola; crew of four plus two passengers; folding table in rear compartment with one inward-facing seat on either side.
YPR-765 prgwt (pantser-rups-gewondentransport) — ambulance vehicle (literally: "casualty transport" since in Dutch military terms, an ambulance carries more medical equipment); unarmed; crew of three plus five passengers; rear compartment has two forward-facing seats on left, bins for personal equipment of the wounded on either side, and can hold two stretchers on either side, suspended from chains.
YPR-765 prmr (pantser-rups-mortiertrekker) — tractor for MO-120-RT 120-mm mortar (mortiertrekker = mortar tractor) with .50-caliber M2 HB machine gun on M26 cupola; crew of seven, including mortarmen; rear compartment has inward-facing, three-seat bench on left and mortar ammunition rack on right.
YPR-765 prv (pantser-rups-vracht) — cargo vehicle (vracht = cargo, freight) with .50-caliber M2 HB machine gun on M113-type cupola; crew of two; empty rear compartment with folding safety screen between crew and cargo.
YPR-765 prat (pantser-rups-anti tank) — tank destroyer armed with an Emerson TOW Under Armor turret as on M901 ITV and a MAG machine gun on a pintle mount; crew of four; rear compartment holds rack with missile reloads on left, inward-facing bench seat and various equipment (such as TOW ground launcher) on right.
YPR-806 prbrg (pantser-rups-berging) — armoured recovery vehicle; in fact, it is based on a modified M113 chassis and hull but using AIFV automotive components.
ACV-300 — Fitted with a 300 hp powerpack similar to M113A3 but with high power.
ACV-350 — Fitted with a 350 hp powerpack.
ACV-S — A stretched version of AIFV with an additional road wheel and extra armour giving resistance to 14.5mm AP projectiles, with an upgraded 350 or 400 hp powerpack. Weight is 18,000 kg. A variety of turrets including 12.7mm, 25mm (FNSS Sharpshooter Turret) and 30 mm are available as well as an Eryx missile launcher and 120mm mortar turret.