Below are some notes I copied from some previous announcements...

Below are some notes I copied from some previous announcements on FAA different certification processes.

Type Certification (TC): A type certificate signifies the airworthiness of a particular category of aircraft, according to its manufacturing design. It confirms that the aircraft is manufactured according to an approved design, and that the design ensures compliance with airworthiness requirements.

Supplemental Type Certificate: A supplemental type certificate (STC) is a certification issued by the FAA to an applicant who has received FAA approval to modify an aeronautical product from its original design (postproduction). Good example is the modification of an aircraft from passenger use to cargo use. The STC, which incorporates by reference the related Type Certificate (TC), which is how the aircraft is originally certified by the FAA. The STC approves not only the modification but also how that modification affects the original design.

Service Bulletin (SB): A Service Bulletin (SB) is a document issued by the manufacturer to raise awareness to all airlines of unusual in-service reported findings. Typically when an airline performs normal maintenance activity they are required to report to the OEM any unusual findings found outside the normally expected findings. If multiple airlines report similar findings then the OEM will issue an industry wide SB to raise awareness to all airlines and to make recommendations on what should be accomplished to correct such issues.

Airworthiness Directive (AD): A document that notifies the owners or operators of a particular model of aircraft that unsafe or potentially unsafe conditions have been discovered which may affect the airworthiness of the model in question and that details any corrective actions which may be necessary to address the deficiency. AD’s will typically make reference to a SB previously issued by the OEM. A good example of an AD is the grounding of the B737Max aircraft. AD’s which require immediate grounding of aircraft is rare, normally an AD will give sufficient notice to the industry so an airline can plan for the required maintenance to be performed.

Alternative Method of Compliance (AMOC): An AMOC is just as it states, an alternative method of complying with a specified way of performing work to meet regulatory compliance. Typically an AMOC would be sort by an airline to the FAA when they may want to perform a task in a different way than how an AD has specified a task to be performed. An airline can submit to the FAA for an approval to receive an AMOC, once received an airline can then perform the work In accordance with their proposed method.

Organization Designation Authorization (ODA): The Organization Designation Authorization program is the means by which the FAA grants designee authority to organizations or companies

C Check and Heavy Check: Typically all aircraft are required to be scheduled for a C check at 24 or 36 month intervals depending on the aircraft type and manufacturer. Also the same is true for performing a Heavy Check (many times referred to as a D Check), these checks are typically referred to as H1 or H2 checks. H1 checks being accomplished at 6 year intervals and H2 check performed at 12 year intervals. Again, depending on the OEM and aircraft type, these intervals can vary slightly.

Issue Paper: An Issue paper (IP) is a document developed by the FAA when new technology is being introduced to the industry. The IP provides internal guidance for its inspectors and industry to use when trying to obtain certification for use of the new technology. The development of the IP can take many months for the FAA to release because it goes through a comprehensive internal review and evaluation by several divisions of the FAA to ensure all possible safety issues are addressed.

Going Forward Paths to certification: There are basically three different paths which can be considered to achieve FAA approval for installation of CVM sensors on aircraft. Not in any order of priority, the three paths are Type Certification (TC), Supplemental Type Certification (STC) or an AMOC.

What factors determine the selection of CVM. All airlines are required to perform scheduled C and Heavy maintenance at specific periods throughout the life of the aircraft. Such maintenance schedules are recommended by the Manufacturer when the aircraft is designed. In general all airlines closely follow the recommendations issued by the manufacturers, however as airline operations vary over time many airlines request approvals from their aviation authority to extend the frequency in which the manufacturers originally recommended maintenance tasks. In addition, as airlines gain experience with operating and maintaining the aircraft SB’s are issued by the OEM and many times AD’s are issued by the FAA or regulatory authorities. As such these additional maintenance tasks require airlines to perform them outside the normally scheduled maintenance intervals for their C or Heavy checks. In many cases this drives additional financial burdens to the airlines.

When considering the use of CVM sensors, the airlines will evaluate the additional financial burdens to perform the required maintenance tasks which are required outside the normally scheduled maintenance intervals. In the case of B737 Aft Pressure Bulkhead (APB), these repetitive inspections are due every approx 1,200 cycles of use (equivalent to approx... 2 times per year), therefore a CVM solution may be considered a more desirable solution than having to relocate the aircraft to the hangar to perform the current method of inspection required. The APB inspection can be performed within 30 minutes at the gate. I'd have to double check again these numbers/time but from this is what I had from my old notes.

Very similar to the APB evaluation, an airline may find that use of CVM sensors to perform certain inspection requirements related to the WiFi antenna mounts to be beneficial. Once sensors are installed, the inspection time can be significantly reduced with the use of sensors. There is no need to remove interior ceiling panels, overhead bag bins and pneumatic ducting to perform the inspections.

SMS Approaches to obtaining final approval from FAA: In 2016, SMS received approval from Boeing to use CVM sensors, on certain B737’s, to perform inspections of the Wing Box Fwd. spar fittings. This approval was granted by Boeing since the SB was issued to the industry as an informational SB and it never reached the level of becoming an AD from the FAA. Boeing engineering was able to approve the use of CVM through its ODA delegation from the FAA.
Since the approval for the B737 wing box inspection was issued, Delta airlines installed sensors on 21 of their B737 aircraft, these sensors have now accumulated nearly 1 million total sensor flight hours.
Since 2016, Delta airlines, in conjunction with SMS, has been actively pursuing Boeing to approve the use of CVM for performing the inspections on the B737 APB, which is subject to an FAA Airworthiness Directive (AD).
With guidance from Delta airlines, another area of good use for CVM sensors is the required inspections for the Wi-Fi antenna mounts on several of their aircraft types. As such, in March of2019 SMS engaged with Delta Engineering firm (not part of Delta airlines) to pursue a Supplemental Type Certificate (STC), to utilize CVM sensors to perform the required Wi-Fi antenna mount inspections.
In both of the above cases, SMS has been informed by Boeing and Delta Engineering, in June of 2019, that the FAA has responded to the request for using CVM technology as; it being a new and novel technology, which means it is required to go through their Issue Paper (IP) process.The Issue Paper process was initiated back in the April-May 2019 timeframe.
The release by the FAA of the IP late last year has allowed Boeing and Delta Engineering to move forward with performing the required certification process related to these two CVM applications.