EASA SIB 2020-17: WITHDRAWN - REPLACED BY ADR.OPS.B.090 AS OF 24 MAY 2025

What to do

Aerodrome operators should verify both the wing span and outer main gear wheel span of aircraft currently using or expected to use their facilities. If either dimension exceeds the aerodrome's certified design characteristics, prior approval from the competent authority is required. Operators should also assess relevant elements listed in AMC1 ADR.OPS.B.090 and follow procedures in ADR.OR.B.040. No immediate regulatory changes are enforced until the update of ADR.OPS.B.090, but vigilance is recommended.

Summary

EASA Safety Information Bulletin 2020-17 is an informational document addressing changes to the aerodrome reference code (ARC) methodology, particularly affecting higher code letter operations at aerodromes. It highlights the reclassification of aircraft such as the De Havilland Canada DHC-8-400 Dash 8 from code letter 3D to 3C based on wing span, and the implications for aerodrome infrastructure design related to outer main gear wheel span (OMGWS). The bulletin advises aerodrome operators and competent authorities on safety considerations due to these changes.

What changed

EASA SIB 2020-17 explains that the ARC code letter determination methodology was updated in CS-ADR-DSN Issue 4 to consider only the wing span (WS) of aircraft, excluding the outer main gear wheel span (OMGWS) which is now used separately for ground manoeuvring characteristics. This change means that the OMGWS is no longer part of the ARC code letter, potentially causing discrepancies in assessing higher code letter operations under ADR.OPS.B.090.

Why it matters

This change matters because aerodrome operators and authorities may inadvertently allow aircraft to operate on infrastructure not designed for their OMGWS, risking safety. For example, the DHC-8-400 Dash 8 could operate on taxiways too narrow for its gear span despite matching the aerodrome's code letter. Awareness and proper assessment of both WS and OMGWS are essential to ensure compliance and safe aerodrome operations.