Public Consultation on proposed Deviation Request UKTSO-C127c.Dev.002

For comments against the introduction of this UKTSO Deviation. It provides a clear and consistent method for assessing interaction between the upper torso restraint and an occupant's neck in seating configurations utilising a 3-point restraint system.

The proposed approach reduces ambiguity within SAE AS8049C by defining acceptable assessment criteria where shoulder belt contact with the Anthropomorphic Test Device (ATD) neck occurs during horizontal or vertical dynamic testing.

The UKTSO Deviation is supported by industry research, including neck injury assessment methodologies and test data from the automotive sector involving comparable restraint systems and belt-to-neck contact scenarios. The proposed criteria therefore represent a proportionate and evidence-based means of demonstrating compliance while maintaining an appropriate level of occupant safety.

Full details of the issue, supporting rationale, and proposed assessment method are contained within Consultation Paper UKTSO Deviation UKTSO-C127c.DEV.002, Issue 1.

A total of 10 responses were received during the consultation period.

The first response supported the proposed UKTSO Deviation without comment.

The second response recommended the consistent use of the term "restraint" throughout the document to improve continuity and readability. 

The third response proposed expanding the pass/fail criteria to permit a null test outcome where contact occurs with an unmodified chest jacket. 

The fourth response recommended the inclusion of a cross-reference to Section 4 to support the evaluation of chest jacket slippage. 

The fifth response addressed modifications to the ATD chest jacket, recommending that any cut surfaces be sealed or subject to periodic inspection to ensure foam degradation does not adversely affect test results. 

The sixth response requested additional clarification regarding the allowable contact zones on the Hybrid II ATD. 

The seventh response recommended the introduction of a marking procedure on the Hybrid II ATD chest jacket to clearly identify the projected position of the head skin. 

The eighth response requested the introduction of defined marking requirements for the belt guide to ensure consistency during assessment. 

The ninth response sought clarification regarding the application of rigid tape and its role within the assessment methodology. 

The tenth response raised concerns regarding consistency of assessment, noting that the marked surface may move during a dynamic test event. 

The UK CAA acknowledges and appreciates the feedback received from all respondents.

For the responses 1, 6, 7, 8, and 10, the comments were carefully considered but were not incorporated into the final UKTSO Deviation. While these comments raised relevant points, their inclusion was not considered necessary to meet the intent of the UKTSO Deviation or to support the proposed assessment methodology.

For the responses 2, 3, 4, 5, and 9, the comments were incorporated into the final UKTSO Deviation. The UK CAA considers these changes to improve the clarity, usability, and robustness of the proposed requirements while remaining aligned with the original intent of the UKTSO Deviation.

As a result of the consultation, several amendments have been made to enhance the final UKTSO Deviation document, while maintaining the objective of providing a clear and consistent means of assessing shoulder belt interaction with the ATD neck during dynamic testing.

The UKTSO Deviation UKTSO-C127c.DEV.002, Issue 1 has now been published in the Aviation Regulation Library.