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

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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.

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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.

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Affected Manuals

– MEL

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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.

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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)

Category: FAA Regulation – Operational Safety
Title: Holdover Time (HOT) Guidelines 2025–2026
Date of Issue: 12 August 2025
Applicability: CAT & NCC Operators, Ground De/Anti-Icing Personnel

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Summary of Change

Winter is around the corner — and with it comes the challenge of safe ground de/anti-icing operations.
On 12 August 2025, the FAA released the updated Holdover Time (HOT) Guidelines for the 2025–2026 season. These guidelines remain the industry’s key reference for determining safe de/anti-icing holdover and allowance times. This year’s edition introduces six new fluid-specific tables, revised generic values, new precipitation categories, and updated allowance times, along with several editorial clarifications.

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Impact on Operators

• New fluid-specific HOT tables have been added for six fluids: ESSPO Nordwing PG2 (Type II), AFLRUS Green Flo Type IV, AllClear Clear IV Flight, ESSPO Nordwing PG4, Newave FCY-EGIV PLUS, and Xinjiang Clearice-IV. These must be incorporated into operational procedures and ground staff references.
• Extended cold weather testing (< –14 °C) now provides fluid-specific HOTs for three existing fluids (COREICEPHOB Type II, PROFLIGHT EG4, PROFLIGHT PG4), ensuring safer planning in very cold snow conditions.
• Removed dilutions: The 75/25 and 50/50 dilutions for Newave FCY-2 (Type II) are no longer valid and should be deleted from manuals.
• Generic adjustments:
  • Type II generics: several HOT values increased following removal of fluid data.
  • Type IV generics: several HOT values decreased due to inclusion of new fluids with shorter times.
• Precipitation category expansion:
  • Type I (aluminum & composite): HOT values for Snow mixed with Freezing Fog increased.
  • A new column for Moderate Snow mixed with Rain has been added across all Type I–IV fluid-specific tables.
• Allowance time changes:
  • Validation table for Type III & IV fluids updated.
  • Increases for Moderate Ice Pellets mixed with Moderate Snow.
  • Additional references for ice pellets mixed with drizzle/freezing drizzle.
  • Clarified guidance for small hail in METAR reports.
• Editorial clarifications throughout tables (temperature references, note structures) for better operational clarity.

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Affected Manuals

• Operations Manual – HOT references and de/anti-icing procedures.
• Ground Ops Manual – Integration of new fluid-specific tables, allowance time validations, and staff briefings.

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TRS Recommendation

Operators should:

• Review and integrate the updated FAA HOT Guidelines before winter operations commence.
• Remove outdated dilution references and adjust procedures for revised HOT values.
• Update all relevant manuals, checklists, and training materials.
• Train both flight and ground personnel on new fluid-specific data, cold-weather updates, and expanded precipitation categories.

TRS supports clients in:

• Updating manuals and documentation in line with FAA HOT 2025–2026.
• Ensuring compliance through readiness checks before the season begins.

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Official Reference

FAA Holdover Time Guidelines – Winter 2025–2026

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Further Information

Download FAA HOT Guidelines – Winter 2025–2026 (PDF)
Visit FAA’s Aircraft Ground Deicing Resources

Category: Operational Procedures
Title: Updated Procedures for Communication Failure and Emergency Descent under Part-SERA
Date of Issue: May 2025
Applicability: EU Member States and EASA-associated countries. Local regulations apply in non-SERA airspace (e.g., Switzerland, UK).

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Summary of Change

ED Decision 2024/007/R amends SERA.14083 and GM1 SERA.11001 to include:

• Clear procedural updates for lost communications under both IFR and VFR operations, including specific timelines and transponder code use.
• Detailed guidance for emergency descent procedures (EDP), including crew responsibilities and post-descent communication requirements.

Impact on Operators

• Flight crews must follow structured escalation protocols for lost COM, including alternate communication methods.
• IFR/VFR flights have distinct procedures, especially under VMC/IMC.
• Emergency descent steps must be rehearsed and reflected in SOPs, with defined PF and PM roles.
• Visual signal monitoring is emphasized near controlled aerodromes.

Lost Communication Procedures

• Initial Steps: Attempt re-establishment on the last frequency; try other ATS channels; use CPDLC, SATVOICE, or relay via other aircraft; set squawk 7600; follow procedures by flight type and condition.
• IFR under IMC: Maintain assigned speed/level for 20 minutes, follow flight plan, hold if necessary, and land within 30 minutes after ETA/EAT.
• IFR under VMC: Set squawk 7601, divert to the nearest suitable aerodrome, and report arrival.
• VFR flights: Stay in VMC, land at the nearest suitable aerodrome, and report arrival to ATS.
• Near controlled aerodromes: Monitor for visual/light signals from ATS.

Emergency Descent Procedures

• PF Responsibilities: Initiate descent and navigate as deemed appropriate, consider leaving airway, follow aircraft and company-specific SOPs.
• PM Responsibilities: Monitor for conflicting traffic (visual, TCAS), ensure SOP compliance, support coordination and communication.
• Post-Descent: Inform ATC of intentions, coordinate return or diversion, complete QRH actions and report as required.
• These procedures apply within EU and EASA FIRs; local rules prevail in non-SERA FIRs.

Affected Manuals

• Operations Manual Part A – General/Basic
• Operations Manual Part B – Aircraft Operating Procedures
• Operations Manual Part D – Flight Crew and Dispatcher Training

TRS Recommendation

TRS recommends operators review and revise all operational documentation to reflect these changes. Priority areas include:

• Proper use of transponder codes 7600/7601 per flight scenario.
• Timely transitions to holding or approach during lost COM under IFR.
• Clear crew tasking during emergency descent scenarios.
• Integration of procedures into training and safety programs.

Official Reference

ED Decision 2024/007/R implementing GM1 SERA.11001 and revised SERA.14083.

Further Information

Easy Access Rules for Standardised European Rules of the Air (SERA)