Despite Troublesome History, Cirrus Gets 'Short-Cut' From FAA

The FAA has posted in the Federal Register a proposal for special conditions for the Cirrus Design Corporation (Cirrus), model SF50 airplane. This airplane will have a novel or unusual design feature(s) associated with a whole airplane parachute recovery system.

The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. The FAA says these proposed special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.

Cirrus proposes the installation of a whole airplane ballistic parachute system (BPS) called the Cirrus Airframe Parachute System (CAPS). This installation couples the BPS with the automatic flight controls. The CAPS will be installed as standard equipment on the SF50 airplane. Unlike the SR20 and SR22 airplanes CAPS, the SF50 CAPS is a supplemental system and no credit for the system will be used to meet part 23 requirements. The SF50 CAPS design will require some performance enhancements over existing technology used in other CAPSs.
The system will consist of the recovery parachute, activation and deployment systems, and autopilot functions. The SF50 CAPS will be designed for a higher gross weight, maximum activation speed, and maximum operating altitude.

The SF50 CAPS system will incorporate an airbag to assist deployment and a system for sequencing deployment and interfacing with the airplane's avionics. The avionics interface is intended to bring the airplane within a valid deployment envelope speed (67-160 KCAS).

The SF50 CAPS is a non-required system that differs from other BPS in that it will interact with the flight control system and other airplane systems. The baseline special conditions must incorporate the required level of safety for the normal BPS as well as the aspect that interfaces with the airplane. Since it is a non required system, additional latitude exists to evaluate and substantiate the system so it will present no additional hazards.

Under the provisions of 14 CFR 21.17, Cirrus Design Corporation must show that the SF50 meets the applicable provisions of part 23, as amended by amendments 23-1 through 23-62 thereto. If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 23) do not contain adequate or appropriate safety standards for the SF50 because of a novel or unusual design feature, special conditions are prescribed under the provisions of §21.16.

According to the Proposed Special Conditions, the applicant must demonstrate by test, or analysis supported by test, that the system will not cause an unacceptable hazard or otherwise exceed the system deployment design loads for the critical flight conditions.

FMI: Proposed Special Conditions