A Military Supplemental Type Certificate (MSTC) is issued by DASA to approve a Major Change to Type Design where it is undesirable to have the change approved as a change to the existing Military Type Certificate (MTC). Under the DASRs there are four reasons an application for a MSTC may be made:
To manage a subfleet where one or more aircraft in a fleet are intended to be configured or operated in a significantly different manner to the remainder of the fleet.
To manage a change that involves a distinct change to the Type Certification Basis (TCB). Generally this will be the result of reliance on prior certification which has adopted a different Primary Certification Code (PCC) than the original MTC. While the change to the PCC may be able to be managed via Military Certification Review Items (MCRIs), it may reduce the complexity of ongoing management of the authorisations by covering the change under an MSTC.
To encompass large and complex changes. While the process for review and approval of a major change to the existing MTC or an MSTC is the same, use of an MSTC provides greater visibility, and as a result greater clarity, of the precise nature and scope of the change. MSTCs are often understood by Defence Operators as being a change of more significance, which warrants greater operational consideration.
To ease management from the perspective of the Military Type Certificate Holder (MTCH). This may be required to provide alignment between the DASR authorisations and authorisations being leveraged via recognition. It may be simpler for an MTCH to manage their obligations if the Defence authorisations are aligned with the OEM authorisations.
A MSTC is usually issued to a Military Type Certificate Holder (MTCH) organisation, which for the ADF context is a government System Program Office (SPO). The MTCH has obligations to ensure they remain eligible to hold the MSTC. A MSTC is required before the aircraft is authorised for flight authorisations subsequent to incorporation of the modification covered by the change to type design.
An application for a MSTC can be made through notifying DASA in writing of the intent to seek issue of a MSTC. This can be achieved by submitting a DASR Form 31, otherwise the submission of the first version of the Certification Programme Plan (CPP) will be taken as the initial application. An application is valid for five years (unless otherwise agreed) to ensure that the standards used to establish the TCB remain current.
In addition to the information required by DASR 21.A.93(b), the application must specify whether the certification data has been prepared completely by the applicant or on the basis of an arrangement with the owner of the type-certification data.
A final application for a MSTC should be made using a DASR Form 31a.
DASA approval. DASA’s approval of a MSTC must be to an eligible applicant and based on an assessment of the demonstration of compliance against the requirements of the TCB11. Where the applicant has specified that it has provided certification data on the basis of an arrangement with the owner of the type-certification data, the MTC holder must have indicated it has no technical objection to the information submitted in the application, and must have agreed to collaborate with the MSTC holder to ensure discharge of all obligations for continued airworthiness of the changed product.
Interaction and timing. A schedule for achieving issuance of a MSTC will be agreed with DASA via the CPP. The CPP is a living document with major certification milestones included in the schedule that are updated as necessary.
DASPMAN Volume 3 Section 7 provides further information on the Major Change Certification process.
MSTCs are normally issued to a Government organisation who is responsible for ensuring the obligations associated with the authorisation are carried out. Once a MSTC is issued by DASA, compliance assurance is achieved through oversight and enforcement activities as they relate to the MSTC holder obligations. Major Changes to Type Design, Major Repairs, Military Permits to Fly and Occurrence Reports can also provide regular opportunities for DASA to assess the performance of the holder.