What are the Airworthiness inspection criteria?|
The airworthiness inspection criteria for certified containers can be found in the CMMs under paragraph Inspection, describe the limits under which the relevant ULD is still airworthy and can be used for flight operation. ULDs that exceed these limits are no longer airworthy and have to be taken out of service. The inspection of a ULD has to be carried out before the ULD is loaded on board of an aircraft.
What are the approval standards?
All certified containers have to meet the requirements listed in a document called NAS3610, soon to be replaced with the new AS36100.
What is a TSO?
A Technical Standards Order (TSO) is a document issued by the FAA. The current issue is TSO C90 (c). Each ULD must carry a TSO marking (a plate or a tag for containers, or engraved for pallets) that contains the manufactures name, the date of manufacturing, a part number, and reference to the TSO under which the ULD was certified. At the moment an equivalent European TSO is issued by the EASA (ETSO C90 c).
Are older containers referring to TSO C90-a en TSO C90-b no longer safe to use?
When the FAA updates the TSO regulations they do not require that older units are scrapped or upgraded, so these TSO references are still valid.
What is the lifetime of a container?
There is no limit in general. Airlines can continue to use a ULD as long as it can be maintained in an airworthy manner.
Where should a damaged container be repaired?
Containers that are damaged must be repaired in an approved ULD repair shop.
What is meant by an approved ULD repair shop?
Maintenance on any aircraft, or the components that are fitted to the aircraft, must be carried out by a company that has been approved by the relevant authority to perform aircraft maintenance work. ULDs must only be repaired in a repair shop that holds a valid approval.
Why are containers often damaged?
Containers have to be as light as possible to save weight on the aircraft, yet they are often handled very roughly in the cargo terminals and forwarders warehouses.
What is included in the manual?
For each ULD a manual is issued. A manual consists of a Component Maintenance Manual (CMM) and an Illustrated Part List (IPL). Depending on the layout, the CMM and the IPL can be combined as a single document or shown as 2 separate documents. For a legal operation, the owner of the ULD should make these documents available for each operator (ramp staff) of his ULDs, as well as for each ULD repair shop.
Why do some containers have metal doors and other fabric doors?
Different airlines have different specifications. Metal door containers provide additional protection against weather and other damage to cargo. Flexible door containers are generally lighter. Flexible doors can have different type of closing mechanisms such as straps with Velcro or a bar locking mechanism.
How do I know how much load a container can carry?
Every container has a maximum gross weight (MGW) limit. However the aircraft itself may also have a lower limit in which case that must be followed.
How are the ULD moved and secured inside an aircraft?
A system of rollers, drive units and container and pallet locks (called a cargo loading system, CLS) is installed in the aircraft to handle the ULD.
Why do some containers have a forkliftable base?
For certain operations where the airlines can accept the higher weight and lower internal volume of a forkliftable container these are preferred over standard base containers as they are less likely to be damaged in operations.
What is a GOH?
Garment On Hangers (GOH) is a provision in the roof structure of a ULD from which coat hangers can be hung. These GOH can be round tubes, T-shape extrusions with holes in them, or welded constructions.
What is a continued seat track?
Pallets have a seat track in the aluminium edge extrusions. In this seat track circular pieces are milled out which allow studs or locks to be installed into the seat track which then allow a container to be fitted on the pallet or a net to be fastened. If the millings are present over the entire length of the pallet extrusions it is called a continuous seat track. If there are only several millings over the entire length of the pallet extrusions it is called a non-continuous seat track. The configuration of the millings can be found in the NAS3610. To which part of the NAS3610 the pallet should comply can be found in the IATA manual if the IATA code is known. The customer should supply the IATA code of the ULD they require.
seat track information (pdf-file)
Is there a relation between ATA and IATA codes?
Yes, see the table with ATA and IATA codes in the pdf-file below.
ATA and IATA codes overview (pdf-file)