Life Time Limitations of ULDs – Part II

This is a continuation of the article published in our newsletter no. 6 in which the life time limitation of ULDs was touched in a more generic way in order to raise the level of awareness at first.

Now it’s time to go a little deeper into the details.

As already expressed in our newsletter no. 6, the equivalent ETSO/TSO (C90 = containers, pallets, pallet nets / C172 = straps) include the requirement that material degradation has to be considered as it will result in a loss of strength.

The OEM have to show compliance with this requirement before any ETSO/TSO approval will be granted.

Defining a life time limitation is only one way to fulfill it and might become the most common practice especially for textiles, webbings and straps.

It is the OEM’s responsibility to find the most feasible way to compensate any material degradation.

There are materials, such as metal, which do not show any degradation, thus requiring no need for any compensation.

Other materials might show a loss of strength during a limited period of time but then become stabil. In this case the degradation could be compensated by using a material with a nominal strength (brand new) which is high enough that its strength after degradation will still meet the minimum performance requirements.

And finally there are materials which show a continuous degradation. In such case the limitation of the life time is the only way to guarantee that the minimum performance requirements are met throughout the parts entire service life.

In any case, the owners/users always have to check the OEM’s instructions as given in the adequate CMMs or as labeled on the article.

Exceeding a set life time might lead to a serious hazard for flight safety.