D-442 FUG is a Hungarian armoured scout car based on the BRDM-1 armoured scout car. It is also known under its Czechoslovak designation OT-65 Otter.
The FUG is similar to the Soviet BRDM-1 armoured scout car, though several differences reflect an independence of the design. It has two waterjets for amphibious propulsion instead of one as in BDRM-1. Because of the similarities with BRDM-1, the D-442 FÚG is sometimes mistaken for a BRDM-1 modification.
It is primarily intended for reconnaissance activities, particularly behind the enemy lines. It was converted to be used in a variety of different roles such as an artillery observation post, a mobile command/observation post and NBC reconnaissance. The Hungarian FUG version can be fitted with a pintle-mounted RPD LMG, but on the OT-65 the main weapon was a 7.62 UK light machine gun (Vz. 59) with electromagnetic release.D-442 doesn't have the BRDM-1 boat-like hull and has much more angular shape which is many times referred to as a "shell" due to its shell-like form. The vehicle shares similarities with both BRDM-1 and BRDM-2. The vehicle is a lot like the BRDM-1 armoured scout car because the standard version has no permanent armament. Like in BRDM-1 and BRDM-2, the commander and the driver were sited in the front of the hull, driver on the left and commander on the right. Also just like both BRDM-1 and BRDM-2, D-442 FÚG has four IR driving lights in the front. The other similarities with the BRDM-1 include the windshields which in combat situation are replaced by armoured shutters with integral vision blocks and two firing ports on both sides of the troop compartment. However to use the armoured shutters the windshields have to be removed. When the shutters are in their opened position they protect driver and commander from being blinded by the sunlight and ensure that the windscreens won't be blurred by rain or snow. Driver and commander can use episcopes to view the battlefield instead of the windshields. The vehicle however has a hanged layout, unlike the BRDM-1 which had a conventional 4x4 layout. The layout is identical to that of BRDM-2, the engine compartment is in the rear and crew compartment is in the front and center. The transmission is located in the middle. Thanks to this the engine is much better protected from enemy fire. The D-442 FÚG has a roof with two hatches over commander's and driver's stations.
D-442 FÚG has an interesting feature. Unlike the BRDM-1 and BRDM-2 which only had hatches on top of the roof, the FUG has a round escape hatch in the floor.
The vehicle is powered by a Hungarian-made Csepel six-cylinder diesel engine. The exhaust is located on the right hand side of the hull. The vehicle is equipped with a winch, intended, among others, for self-recovery when stuck in difficult terrain. To improve cross-country capability, central tire-pressure regulation system can also be used to decrease the pressure in all tires before crossing an obstacle and to increase it to the required level after the obstacle has been crossed. The tire pressure can be reduced and controlled by the driver from his post by the means of valves and a pressure indicator. Like the BDRM-1 and BRDM-2, it has four auxiliary belly wheels which the driver can hydraulically lower to assist the vehicle in crossing obstacles and gaps. Speed is sacrificed in this mode of travel, which is accomplished in first gear at a speed of five to eight kilometers per hour.
Water obstacles can be crossed by swimming. In water, the vehicle is driven by two water jets controlled by the driver which are steered by reversing the thrust. Stability of the vehicle in water is improved by a trim board which is erected at the front before entering the water. While in its traveling position it serves as additional armour.
The armour on the vehicle which is composed of welded steel, protects it fully against small arms fire and small shell fragments but doesn't protect it against big artillery fragments and a .50-calibre machine gun fire which can penetrate D-442 FUG maximum armour of 13 millimeters and D-944 PSzH maximum armour of 14 millimeters. The D-442 FÚG-series and D-944 PSzH tires are not protected by armour. They are particularly vulnerable to puncture from fire of all kinds.
D-442 FUG armoured scout car has its weak spots however. One of the biggest flaws of the D-442 FUG armoured scout car is the lack of permanent armament. To operate the pintle-mounted 7.62 mm light machine gun in the front the soldier had to expose himself to enemy fire. This issue was taken care of in D-944 PSzH developed in late 1960s, which had a small two part side door on both sides of the hull and a turret armed with 14.5 mm KPVT heavy machine gun and 7.62 mm coaxial general purpose machine gun. Both weapons can be elevated between -5 and +30 degrees. The turret has two IR spotlights, one next to the armament and the second one on top of the turret. It also has a radio antenna on back of the turret. Like in the BRDM-2 there two hatches over driver's and commander's stations in the front of the turret. Contrary to the popular belief the turret used in D-944 PSzH is different from the BPU-1 turret used in BRDM-2. The vehicle also introduced NBC protection system and infrared night-vision equipment.
Even though the D-944 PSzH resembles the BRDM-2, it does not have the flaw related to entering and exiting the vehicle (See BRDM-2 for details) which is present in D-442 FUG, because the vehicle has side hatches as opposed to the front roof hatches. Because the vehicle uses an only slightly modified hull of D-442 FUG it also has the round escape hatch in the floor.