NTSB · Safety Recommendation
Safety Recommendation A-21-053
Recommendation
TO THE EUROPEAN UNION AVIATION SAFETY AGENCY: Require the submission and consideration of system safety assessments addressing the landing gear antiskid system for the certification of future transport-category airplane designs. The certification should ensure that the system safety assessments are consistent with the intent of Acceptable Means of Compliance 25.1309, Systems Design and Analysis, and that the assessments evaluate and mitigate the potential for human error that can lead to a cross-wiring error.
Safety Issue and Context
This report discusses the October 17, 2019, accident involving a Saab SA-2000 airplane, operated by Peninsula Aviation Services Inc. d.b.a. PenAir flight 3296, which overran the end of runway 13 at Unalaska Airport, Unalaska, Alaska. The airplane was substantially damaged during the runway overrun; as a result, of the 3 crewmembers and 39 passengers aboard, 1 passenger sustained fatal injuries, and 1 passenger sustained serious injuries. Eight passengers sustained minor injuries, most of which occurred during the evacuation.
Safety issues identified in this report include the potential for cross-wiring of airplane antiskid brake systems; insufficient Federal Aviation Administration (FAA) guidance to identify safety risks for air carriers experiencing significant organizational changes, including bankruptcy, acquisition, and merger; lack of FAA consideration of runway safety area dimensions during the process of authorizing an air carrier to operate its aircraft at a specific Title 14 Code of Federal Regulations Part 139 certificated airport, and the benefits of safety management systems for design, manufacturing, and maintenance organizations.
As a result of this investigation, the National Transportation Safety Board makes six new safety recommendations to the FAA, three new safety recommendations to the European Union Aviation Safety Agency, and one new recommendation to the Saab Group.
Response History
October 31, 2022 · NTSB Correspondence · European Aviation Safety Agency
We note that you are reviewing existing requirements for evaluating and mitigating the potential for human error during the design and certification activities specified in CS-25. We also note that, as part of this review, you are considering methods to better mitigate the risk of human errors that could lead to cross-wiring of antiskid brake system components, including the wheel speed transducers. Pending our review of your findings and a plan for completing the recommended actions, Safety Recommendation A-21-53 is classified OPEN--ACCEPTABLE RESPONSE.
February 15, 2022 · Recipient Response · European Aviation Safety Agency
-From Erick Ferrandez, Head of Safety Intelligence and Performance Department: The European Union Aviation Safety Agency (EASA) has initiated a review of existing provisions related to the consideration of human errors (in particular maintenance errors) during design and certification activities in CS-25 (Certification Specifications and Acceptable Means of Compliance for Large Aeroplanes). As an initial indication, some provisions are already present in AMC 25.1309 (System design and analysis) (refer to CS-25 Amendment 27):
-Section 6.b(2) presents the principles and techniques that need to be used in the fail-safe design concept incorporated in CS-25. This includes the ‘Error-Tolerance that considers adverse effects of foreseeable errors during the aeroplane's design, test, manufacture, operation, and maintenance’.
-Section 9.b(1)(v) states that the analyses done to substantiate the probabilities of failures conditions must consider, among other items, ‘the effect of reasonably anticipated errors when performing maintenance actions’.
-Section 10.c specifies that ‘the requirements of CS 25.1309(b) are intended to ensure an orderly and thorough evaluation of the effects on safety of foreseeable failures or other events, such as errors or external circumstances, separately or in combination, involving one or more system functions. The interactions of these factors within a system and among relevant systems should be considered’.
-Appendix 1 (Assessment methods) section f (Common cause analysis) provides the following:
o‘(1) Zonal Safety Analysis. This analysis has the objective of ensuring that the equipment installations within each zone of the aeroplane are at an adequate safety standard with respect to design and installation standards, interference between systems, and maintenance errors. In those areas of the aeroplane where multiple systems and components are installed in close proximity, it should be ensured that the zonal analysis would identify any failure or malfunction which by itself is considered sustainable but which could have more serious effects when adversely affecting other adjacent systems or components.