Holdover Time Guidelines – Winter 2025–2026

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

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.

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  • Removed dilutions: The 75/25 and 50/50 dilutions for Newave FCY-2 (Type II) are no longer valid and should be deleted from manuals.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.

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.

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.

Official Reference

FAA Holdover Time Guidelines – Winter 2025–2026

Further Information

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

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