When designing an Aircraft Unit Load Device (ULD), careful thought is given to making the most of the aircraft’s cargo space. Unfortunately, aircraft holds come in many shapes and sizes, which means that ULD’s also have to come in many shapes and sizes.
Since ULDs are often transferred between different types of aircraft, this gives rise to three types of fit: optimal fit, non-optimal fit and no fit:
- Optimal fit: the ULD’s contour is the same as the aircraft’s hold
- Non-optimal fit: the ULD’s contour does not exactly match the hold’s contour
- No fit: the ULD does not fit the aircraft’s hold
Clearly, a ULD that fits the contour of the hold maximises the aircraft’s cargo space. In addition, a ULD can be an optimal fit for one or more than one type of aircraft. That doesn’t mean this ULD can’t be used in another type of aircraft if it’s not an optimal fit. In fact, it may be compatible with several different aircraft. It simply won’t be making the most of every hold’s space.