Instrument Certification and Approval

Rules for certifying instruments for flight on the NSF/NCAR C-130 and GV aircraft.


The C-130 and the GV aircraft technically operate under different aviation rules. The C-130 is operated in the "public" category. The payloads are approved for flight without consultation with the FAA. Mid-project changes can be made at the facility discretion by applying the same process.

The GV is operated under a Standard Airworthiness Certificate. This means that after first passing an RAF review, each payload must pass through an FAA certification process that requires standardized and detailed documentation. This process typically takes a minimum of one month to complete, resulting in a payload that cannot undergo a modification (i.e. external configuration change; increase in payload weight; or increase in power consumption) without requiring another FAA approval.

The process of RAF payload approval on either aircraft is the same and is aimed to evaluate structural compatibility, electrical conformity and safety and ultimately, flight safety. The RAF process consists of a series of reviews and is compliant with the FAA requirements.

New instruments still under development are often included in research payloads planned by the researchers. While deploying cutting edge new instruments can be highly beneficial to field programs, field deployments have very specific deadlines and it is difficult to fully assess the airworthiness, functionality, and availability of new systems on such a constrained time line. Therefore the new systems must be flight tested and proven safe and operational before participation in a scientific research project.

The deployment schedule for each approved field project includes a very specific and limited upload interval when the entire research instrumentation payload must be installed on the aircraft. Due to various scheduling constraints only a minimal amount of pre-deployment flight testing is allotted to ready the payload for the actual deployment into the field.

A key component of the new process is the provision of annual flight test programs. These programs called ARISTO are opportunities for instrument developers to flight test their new systems without the pressure of an imminent field deployment while providing the RAF with the opportunity of evaluating and certifying each system as a routine task. The flight test programs will be scheduled well in advance and advertised within the research community.

1.1 New Instruments

New instruments that have never flown on any aircraft before must successfully complete a flight test sequence prior to approval for use on a field deployment. Such testing must be done to insure both the airworthiness and functionality of the instrument. PIs will be asked to denote which instruments are "required" to meet their scientific goals. "Required / mission critical" sensors must complete this process at least three months prior the scheduled start of the payload integration. The "required" vs "optional" determination for each project is based on the list of go-no go instrument conditions provided by the PIs. "Clones" of previously flown instruments will be exempted from this requirement on a case-by-case basis depending on a review of any documented differences between the two systems. Key factors that will be evaluated are: non-metallic materials; power consumption; and wiring. Sensors considered to be "optional" to the scientific goals of the experiment may delay testing until the project specific, pre-deployment flight tests with the clear understanding that a failure to perform satisfactorily may result in their removal from the payload prior to the field deployment, or lack of science quality data for the project. 

GV: Participation on any flight test program on this platform requires that the instrument pass through the FAA certification process. Details on this process, including material & power/wiring constraints and design & fabrication documentation schedules can be found on the RAF plans and schedules webpage. Prior certification as part of a flight test program should ensure a smooth transition to the field project certification.

 C-130: The requirements on materials and power / wiring constraints are the same as the GV. No formal FAA certification is required, but documentation on key system components must still be submitted to the RAF on the certification schedule outlined in the GV section above.

1.2 Instruments Previously Flown

Instruments that have successfully been flown on one of the NCAR aircraft, or any other manned research aircraft in the international fleet, will typically be exempt from the in-flight functionality test requirement prior to participation in a scientific project. However, systems that have undergone modification since their last deployment must be re-evaluated to establish the extent of the changes. If the modifications are deemed to be significant (ie. replacement of a primary component with new technology), some form of additional flight testing may be required. Key factors that will be evaluated are: non-metallic materials; power consumption; and wiring. Additionally, if significant differences exist between the NSF platform and the one on which the instrument has flown (such as airspeed or an inlet system), participation in a special flight test program (ARISTO, above) may be required.

GV and C-130: All documentation requirements outlined for New Instrumentation (above) apply, but test flight in advance of the science project may not be required. Certification on another platform or by another regulatory agency on a similar platform (like the DLR "HALO" G-550) does NOT transfer between platforms, but the basic documentation should be very similar. All certification documentation must be submitted to the RAF engineering according to the timelines communicated to the instrument developer by RAF project managers; failure to provide the required certification documentation will result in the ineligibility to fly on the aircraft. Instrument providers may be required to rebuild structural and electrical components or replace unsuitable materials as part of the certification process. Project specific payload flight testing will be conducted just prior to deployment to the field site.