On 1 July 2015, the NLR received a national Design Organization Approval (DOA) from the Environment and Transport Inspectorate (IL&T). This signifies that the NLR can design modifications for its research aircraft Cessna Citation (PH-LAB), and demonstrate that these modifications meet the applicable airworthiness requirements.
The reason for this accreditation is changes made to Dutch aviation law, which take effect on 1 July 2015. The approval adheres to EASA guidelines (part 21) and is based on the NLR’s described processes for the design of modifications to the Cessna Citation in its Design Organization Exposition. The NLR employs special design engineers and Compliance Verification Engineers (CVE) who are responsible for ensuring these processes are well executed. The latter conduct independent verifications of the work completed by the design engineers.
RenÃ© Eveleens, manager of the Aircraft System department, and head of the Research Aircraft Design Organization (RADO): “These are complex dossiers. The NLR receives the DOA as verification that it is correctly following the described and approved processes, including by ensuring a strict separation between the designers and the CVE-ers. In addition to this strict separation, traceability is an important associated issue. Who has done what, and what is its demonstrability? The dossiers must be correct, so that it is clearly established why a certain modification to the aircraft is in fact safe.”
An example of such a modification could be the installation of a laser, as occurred during the DELICAT-project, whereby the NLR designed the entire installation process.
Clients and project partners will notice little change from this approval, as all flights were always undertaken with safe modifications. Previously, such modifications were certified by Official Inspectors working under the supervision of IL&T. Now that the NLR’s design organisation has received accreditation, the CVE will assume this task.
The NLR is the first accredited design organisation to receive this accreditation for experimental objectives, and may also advise other clients in this area.