ASTM WK94219
New Specification for Computer Based Control Systems (CBCS) for Light Sport Aircraft
1. Scope
This standard defines the requirements for computer based control of major, hazardous and catastrophic failure conditions. The approaches identified provide requirements, which will implement the necessary and sufficient controls. These approaches are based on the type of failure condition being controlled and are to be applied on a failure-by-failure condition basis as identified in the Standard Practice for Simpli?ed Safety Assessment of Systems and Equipment in Small Aircraft (F3309). These requirements apply to computer-based or complex electronic-based systems that control a safety-critical process or device. These systems include any hardware, software or firmware used to prevent a major, hazardous or catastrophic failure condition, regardless of the media that the software or firmware that resides on. This includes any Commercial Off the Shelf (COTS) software, firmware or hardware integrated into the CBCS design. CBCS requirements are applied at the system level. CBCS requirements do not need to be applied to lower level components, such as sensors or actuators, if system level compliance can be established.Keywords
Safety Critical Commanding;; Must Work Function;; Must Not Work Function;; Fault Tolerant;; Inhibit;; Separate Control Path;; Fault Containment; Fail SafeRationale
CBCS implementations use computer hardware and software as an integral part of an aircraft system safety process. CBCS requirements provide aircraft manufactures a means of implementing engineering and management principles, criteria, and techniques to provide hardware failure and software error tolerance to minimize risks associated with the use of computers to control failures. CBCS requirements will be applied to systems with computer or complex-electronic control whose inadvertent operation, or failure, can result in a major, hazardous or catastrophic failure condition. A CBCS must not introduce failures in the aircraft it is controlling nor exacerbate failure conditions in other vehicle systems. This standard defines the requirements for computer-based control of major, hazardous and/or catastrophic failures aboard Light Sport Aircraft (and potentially other aircraft categories).
Work Item Status
Date Initiated: 03-17-2025
Technical Contact: R McAllister
Item: 000
Ballot:
Status: