Once released from the tow craft near the front, they were to land on any convenient open terrain close to target, hopefully with as little damage to the cargo and crew as possible as most landing zones (LZ) were far from ideal. The one-way nature of the missions meant that they were treated as semi-expendable leading to construction from common and inexpensive materials such as wood. Most nations seriously attempted to recover as many as possible, to re-use them, so they were not originally intended to be disposable, although resource-rich nations like the US sometimes used them as if they were, since it was easier than recovering them.