Tank desant (танковый десант, tankovyy desant) is a military combined arms tactic, where infantry soldiers ride into an attack on tanks, then dismount to fight on foot in the final phase of the assault. Note that this differs from infantry troops merely riding on tanks as a form of ad-hoc transportation. Desant (from the descendre, "to disembark") is a pan-Slavic general term for airborne or parachute drops and naval infantry amphibious landing operations. The tactic was used as an expedient by the Red Army during World War II. Tank desant troops (tankodesantniki) were infantry trained in the tactic in order to offer small-arms support in suppression of enemy anti-tank weapons or enemy infantry using anti-tank grenades. After the war, T-55 and T-62 tanks were built with hand-holds for this purpose. In northern areas during winter, similar tactics were used by Soviet infantry riding the skids of aerosani or towed behind them on skis. Nowadays, this tactic is very rare (outside of dire emergencies) in well-equipped armed forces, with front-line troops usually riding in armoured personnel carriers or infantry fighting vehicles. The tank desant tactic, like more conventional airborne and amphibious operations, was used to achieve fundamental goals of maneuver warfare: "surprise, leverage, simultaneity and interchangeability." The use of tank desant was only prescribed within the first kilometer of the forward edge of the combat area for only the simplest of tactical mission objectives, since the circumstances would be difficult for the troops engaged. Riding on tanks during actual combat is very dangerous. Tank riders are very vulnerable to machine gun and high explosive fire, and the high silhouette of most tanks would draw enemy fire. Smoke and covering fire may be used to reduce the hazards. Tank riding is mostly used when troops need to move faster than is possible on foot and there is a shortage of motor transport or armoured personnel carriers. Usually, the infantry and their heavy weapons were assigned to specific tanks well before the execution of the mission.