EASA CS-MMEL Updates

Category: EASA Regulatory Update
Title: EASA CS-MMEL Updates
Date of Issue: December 2025
Applicability: CAT and NCC Fixed-Wing Operators

Summary of Change

EASA has published targeted MMEL/MEL updates (CS-MMEL Issue 4 and CS-GEN-MMEL Issue 3).
This update provides a concise overview of the MEL items that require review.

CS-GEN-MMEL Issue 3 and CS-MMEL Issue 4 – What Has Changed

EASA has published CS-MMEL Issue 4 and CS-GEN-MMEL Issue 3 (ED Decision 2025/021/R).
The MMEL philosophy remains unchanged. The impact is limited to specific items and ATA chapters.

Relevant technical changes are as follows (by ATA chapter):

ATA 23 – Communications

  • HF COM: amendments are only relevant in conjunction with SATCOM installations.
    Clarification of relief logic where HF and SATCOM are considered together as part of the long-range communications concept.

ATA 25 – Equipment / Furnishings

  • Storage bins and compartments: clarified relief conditions, including securing inoperative bins, placarding (“DO NOT USE”), restrictions on storage of loose items, and required crew procedures. For overhead bins without partitions, the entire bin is considered inoperative.
  • Cargo restraint systems: clarified relief where restraint equipment is missing or inoperative, provided approved cargo loading limits are observed or the compartment remains empty.
  • First-aid kits – additional equipment: additional equipment may be inoperative, incomplete or missing. Required additional equipment may be incomplete for flights to a destination where replacement is possible, limited to a maximum of two calendar days. The definition of “additional equipment” is explicitly linked to the Air Operations Regulation.

ATA 31 – Indicating / Recording Systems

  • New MEL item introduced: Usage Monitoring System (UMS).

ATA 32 – Landing Gear

  • New MEL item introduced: Tyre Pressure Monitoring System (TPMS).

ATA 34 – Navigation / Surveillance

  • ACAS: clarified MEL relief logic for degraded modes.
  • New MEL item introduced:  Runway Overrun Awareness and Alerting System (ROAAS)
  • Navigation systems (ADF): clarification regarding inoperative systems installed in excess of those required for the intended route.
  • Enhanced Surveillance (DAPs):
    • Operations in the Single European Sky: time-limited relief (maximum three consecutive calendar days).
    • Operations outside the Single European Sky: relief permitted when compatible with applicable airspace requirements.
  • ADS-B OUT:
    • Operations in the Single European Sky: time-limited relief (maximum three consecutive calendar days).
    • Operations outside the Single European Sky: relief permitted when compatible with applicable airspace requirements.

Operational relevance:
The MEL now explicitly distinguishes between SES and non-SES operations. MEL application must reflect the airspace actually operated.

ATA 35 – Oxygen

  • Minor clarifications to existing MMEL relief conditions.

Affected Manuals

– MEL

TRS Recommendation

– Review MELs against CS-MMEL Issue 4 or CS-GEN-MMEL Issue 3 (as applicable), limited to the ATA chapters listed above and prepare changes for next MEL revision.

Official Source

– EASA CS-MMEL Issue 4 – Change Information (ED Decision 2025/021/R) – EASA Information Security (Part-IS)

– EASA CS-GEN-MMEL Issue 3 – Change Information (ED Decision 2025/021/R)

/by

EASA Part-IS – ORO Amendment 29 & SPA Amendment 17 – Mandatory Changes for 2026

Category: EASA Regulation – Information Security & Operational Requirements
Title: EASA Part-IS – ORO Amendment 29 & SPA Amendment 17 – Mandatory Changes for 2026
Date of Issue: December 2025
Applicability: NCC & CAT Fixed-Wing Operators, Operators with PBN/RNP, RVSM and ETOPS Approvals

Summary of Change

EASA has released three regulatory packages that materially change how operators must manage digital systems and operational data:

  1. Part-IS (Information Security) – introduces a mandatory Information Security Management System (ISMS), including risk assessment, incident reporting, supplier oversight and a new Information Security Management Manual (ISMM).
  2. AMC/GM to Part-ORO — Issue 2 / Amendment 29 – aligns SMS and ISMS requirements and strengthens expectations for digital-process oversight within OM-A, OM-B and OM-D.
  3. AMC/GM to Part-SPA — Issue 1 / Amendment 17 – updates data-integrity requirements for PBN/RNP/RNP AR, RVSM and ETOPS operations, with emphasis on digital navigation and performance data workflows.

All changes originate directly from the newly published AMC/GM documents, including the Information Security – December 2025 package (ED Decisions 2025/013/R, 014/R, 015/R).

Impact on Operators

The new requirements shift operational oversight from “systems used” to “data relied upon”. Any digital process influencing operational decisions must now be assessed, validated and documented.

Key operator impacts include:

  • ISMS becomes a mandatory core system, not an add-on to SMS.
  • Digital systems must undergo structured risk assessment.
  • NAV-data chains, performance data, EFB workflows and OCC tools must be demonstrably controlled.
  • Supplier oversight becomes a regulatory obligation; cloud-based systems included.
  • SPA approvals (PBN/RNP/RNP AR, RVSM, ETOPS) now depend on documented data-integrity controls.
  • Manuals must reflect updated responsibilities, data flows and competence requirements.

Authorities will review ISMS integration and digital-data governance during 2026 audits.

Affected Manuals

OM-A: Management system, ISMS responsibilities, data-flow descriptions, integration with SMS.
OM-B: Navigation-data processes, performance and W&B workflows, configuration control, SPA-related digital dependencies.
OM-D: Training & competence requirements linked to information security.
ISMM (new mandatory manual): Required under IS.I.OR.250; defines all ISMS processes, controls and responsibilities.

TRS Recommendation

  1. Start ISMS implementation immediately – policy, scope, digital-system mapping.
  2. Conduct an ISAP-based risk assessment – required by the AMC/GM.
  3. Update OM-A/B/D + ISMM as a single, consistent package.
  4. Validate NAV-data and performance workflows – required for SPA compliance.
  5. Establish supplier-oversight mechanisms – contracts, service documentation, verification steps.
  6. Prepare audit evidence early – authorities will expect complete documentation in 2026.

TRS provides a structured ISMM Template, aligned with the AMC/GM requirements, to accelerate implementation.

Official Source

Further Information

For operators requiring support with ISMS implementation, manual revisions, or compliance, TRS Aviation Consulting provides dedicated assistance.

/by