Final rule published August 20, 2026 (FR Vol. 91, No. 160; doc. 2026-16954) · 14 CFR Part 39 · Docket FAA-2025-2555 · Issued August 17, 2026
Quick Answers
What must operators do? At the next engine shop visit after September 24, 2026 where the 3rd stage HPC rotor is exposed, replace the full set of 3rd stage HPC rotor blades with parts eligible for installation (P/N 6C8368, 6C8403 or later approved; or blades modified to 6A8353-001 / 6A8688-001).
Why? Multiple failures of 3rd-stage HPC rotor blades (P/Ns 6A8353 and 6A8688) on IAE V2500-A5 engines have caused engine fires, unplanned engine removals, aborted takeoffs, and in-flight shutdowns (IFSD). An improved shroud coating process significantly reduces the risk of fracture.
Which engines are affected? IAE AG V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, V2531-E5 and V2533-A5 engines with an affected 3rd stage blade installed — approximately 1,462 engines on US-registered aircraft.
How much does it cost? Replacement with reworked blades costs ≈$30,085 per engine (1 work-hour × $85/hr + $30,000 parts); a full set of new blades costs ≈$225,000 per engine if the removed blades are unserviceable. US-fleet cost with reworked blades ≈$43.98 million.
Quick Compliance Summary
| Field | Detail |
|---|---|
| Regulatory body | Federal Aviation Administration (FAA) |
| Instrument | Airworthiness Directive 2026-17-03 — final rule under 14 CFR Part 39 (Amdt 39-23446) |
| Status | Final — effective September 24, 2026 |
| Issued / Published | Issued August 17, 2026 · Federal Register publication August 20, 2026 (doc. 2026-16954) |
| Applicability | IAE AG V2522/2524/2525-D5/2527/2527E/2527M/2528-D5/2530/2531-E5/2533-A5 engines with 3rd stage HPC rotor blade P/N 6A8353 or 6A8688 installed (A320ceo family, A340-200/300, 757, MD-90, C-17 depending on configuration) |
| Unsafe condition | 3rd stage HPC rotor blade shroud wear and fracture → engine fire, reduced control, IFSD |
| Required action | Full-set replacement of affected 3rd stage HPC rotor blades at the next engine shop visit where the 3rd stage rotor is exposed |
| Compliance trigger | Shop-visit based (induction into shop for maintenance after the effective date where 3rd stage rotor exposed) — not calendar-driven |
| Cost | ≈$30,085/engine reworked (≈$43.98M US fleet), ≈$225,000/engine new set; no IBR in the AD |
| Enforcement | FAA AMOC path under 14 CFR 39.19; extensions possible on safety-justified showing (para (i)(1)) |
Who Should Read This
- Engine maintenance / MRO managers (V2500 shops) — shop-visit trigger planning, blade eligibility tracking
- Continuing Airworthiness Managers (CAMOs) of A320ceo / 757 / MD-90 fleets — AD tracking against shop visits
- Line/transit maintenance planners — avoiding unwarranted early shop induction
- Procurement / spare-parts teams — blade availability, rework vs new-set economics
- Lessors and technical management companies — AD status in return-condition records
- Engine OEM / MRO network (IAE, LHT, SIAEC style) — SB V2500-ENG-72-0716 compliance mapping
At a Glance
| Item | Detail |
|---|---|
| AD number | 2026-17-03 (Amdt 39-23446; Docket FAA-2025-2555) |
| Effective date | September 24, 2026 |
| Affected blades | 3rd stage HPC rotor blades P/N 6A8353 / 6A8688 |
| Eligible replacements | P/N 6C8368 / 6C8403 / later approved; or modified 6A8353-001 / 6A8688-001 |
| Compliance method | Replacement per IAE AG SB V2500-ENG-72-0716 (Oct 4, 2024) demonstrates compliance |
| NPRM history | Published November 18, 2025 (90 FR 51600); 45-day comment period; 7 commenters |
| US population | ≈1,462 engines |
| Parts availability | OEM confirmed no shortages expected (rework available; new hardware production increased) |
What This Does
AD 2026-17-03 addresses a fatigue/failure condition in the V2500-A5’s 3rd stage high-pressure compressor rotor. Manufacturer investigation determined that blades P/Ns 6A8353 and 6A8688 are susceptible to shroud wear and blade fracture; an improved coating process (introduced with the current blade standard) increases shroud durability and reduces the risk of fracture. The AD makes replacing the full set of affected blades with eligible parts mandatory at the next engine shop visit after the effective date when the 3rd stage rotor is exposed.
The FAA clarified during the rulemaking (in response to United) that only engines inducted into a shop visit after the effective date, when the 3rd-stage rotor is exposed, are subject to replacement — engines already in the shop before September 24, 2026, are not required to comply pre-induction.
What it does NOT do
- It does not impose calendar- or flight-cycle-based compliance thresholds — the trigger is shop-visit-based.
- It does not ground the fleet or restrict dispatch.
- It does not mandate repetitive inspections as an alternative (no inspection exists for this condition; the FAA explicitly declined Lufthansa Technik’s request for an inspection-based AMOC).
- It does not incorporate any material by reference — the AD text itself contains the full compliance procedure.
Why This Exists Now
The condition surfaced through service experience: multiple reports of failed 3rd stage HPC rotor blades resulted in engine fires, unplanned engine removals, aborted takeoffs and in-flight shutdowns. The NPRM published on November 18, 2025, drew seven comments — ALPA (supported), American Airlines, Citizens Rulemaking Alliance, IndiGo, Lufthansa Technik, SIAEC, and United. The FAA rejected requests to withdraw the rule or to substitute inspections, citing the airworthiness limitation and the absence of any effective inspection method, and retained the shop-visit-based trigger with clarifying definitions (3rd-stage HPC rotor blade exposure; engine shop visit).
Operational Impact Matrix
| Affected function | Action required | Deadline / driver | Reference |
|---|---|---|---|
| CAMO / Continuing Airworthiness | Enter AD 2026-17-03 in tracker; map per-tail/engine shop-visit windows | Effective Sep 24, 2026; shop-visit driven | AD 2026-17-03 / Docket FAA-2025-2555 |
| Engine MRO / V2500 shop | Confirm blade P/N tracking; schedule full-set replacement at 3rd-stage exposure | At next eligible shop visit | IAE SB V2500-ENG-72-0716 |
| Procurement / spares | Plan rework vs new-set decision per engine; confirm supply lead times | Pre-shop-visit | AD (no IBR; OEM supply assurances) |
| Flight Operations | No dispatch restriction; coordinate shop induction with network planning | — | AD text |
| Lessors / technical records | Document blade eligibility and compliance evidence in records | At each replacement | AD records requirement |
| Foreign authorities | Expect mirror ADs (EASA etc.) referencing the same condition/SB | Authority-driven | AD publications |
Cost & Benefit
| Item | Amount |
|---|---|
| Affected engines (US registry) | ≈1,462 |
| Replacement with reworked blades | 1 work-hr × $85/hr + $30,000 parts = $30,085/engine |
| Full new blade set (unserviceable blades) | ≈$225,000/engine |
| US fleet cost (reworked assumption) | ≈$43,984,270 |
| Small-entity impact | 8 small entities / 23 affected; high-case cost up to 18.3% of revenue (rental/leasing) |
Costs can be absorbed into regularly scheduled maintenance — the FAA determined the AD triggers no downtime or scheduling disruption because replacement is performed at shop visits.
What Operators Should Do Now
- Confirm which engines in your fleet carry affected 3rd stage blades (P/N 6A8353/6A8688) and track shop-visit windows.
- Engage your MRO on the rework route vs. the new-set route per engine; lock in supply ahead of high-activity periods.
- Align your AD tracker with the shop-visit trigger definition (induction after Sep 24, 2026, when the 3rd stage rotor is exposed).
- Where compliance timing creates a risk, prepare an AMOC request under 14 CFR 39.19 (para (i)(1)) with a safety-justified extension rationale.
- For non-US operators, monitor local authorities’ mirror ADs and their references to IAE SB V2500-ENG-72-0716.
Compliance Checklist
- AD 2026-17-03 entered into the AD/airworthiness tracker with effective date Sep 24, 2026
- Fleet engine records interrogated for affected 3rd-stage blade P/Ns
- Shop-visit induction windows mapped against the exposure trigger
- Rework vs new-set cost decision made per engine; spares availability confirmed
- Compliance documentation (blade eligibility, replacement evidence) defined
- AMOC readiness reviewed (14 CFR 39.19)
- Foreign mirror-AD monitoring assigned (if operating outside US)
Regulatory Interplay
- Service bulletin: IAE AG SB V2500-ENG-72-0716 (dated Oct 4, 2024) references the current blade standard; performing the replacement in accordance with it demonstrates compliance because it changes the blade P/Ns to eligible ones.
- Adjacent airworthiness: this AD joins the recent wave of structural ADs (737 MAX bear strap, 747-8F stringers) as the FAA extends its precautionary posture — now into engine-rotor life limits.
- Next-step view: the FAA noted the affected population may be smaller than 1,462, given operators who have already completed the SB — the effective impact depends on your fleet’s SB status.
ARW take: the notable feature is the shop-visit trigger. Operators that run open-ended “engine monitoring” or deferred shop entries need to hard-wire this trigger into their induction planning — an engine inducted tomorrow without the blades changed returns to service non-compliant and cannot be released under the AD. The second watch item is capacity: with roughly 1,462 US-registered engines and the same V2500 fleet served by a small number of MRO networks (IAE partners, LHT, SIAEC-style shops), shop-visit clustering is the real risk to schedule. Book your blade work early.
Key Dates
| Milestone | Date |
|---|---|
| NPRM published | November 18, 2025 (90 FR 51600) |
| Final rule issued by FAA | August 17, 2026 |
| Federal Register publication | August 20, 2026 (doc. 2026-16954) |
| AD effective; compliance trigger starts | September 24, 2026 |
| First shop-visit compliance wave | Shop-visit driven — plan against your induction schedule |
Source Documents
- FAA/Federal Register — Airworthiness Directives; International Aero Engines AG Engines (AD 2026-17-03)
- EASA AD mirror — AD_US-2026-17-03 (FR Vol. 91 No. 160 full text)
- Docket — FAA-2025-2555 (regulations.gov)
FAQ
Is my aircraft grounded on September 24? No. Compliance is triggered at the next engine shop visit after the effective date when the 3rd stage rotor is exposed — not by calendar.
Do I have to use new blades? No. Replacement with reworked blades (≈$30,085/engine) satisfies the AD; new sets (~$225,000) are only needed if removed blades are unserviceable.
Can I inspect instead of replace? No. The FAA determined no effective inspection exists for this condition and declined requests to allow an inspection-based AMOC.
What if my engine is already in the shop when the AD becomes effective? Engines inducted before the effective date are not required to comply at the time of induction — the trigger applies to shop visits starting after September 24, 2026.
Does replacing per the IAE Service Bulletin count? Yes — IAE AG SB V2500-ENG-72-0716 (Oct 4, 2024) changes blade P/Ns to eligible parts and demonstrates compliance (per the FAA’s response to American/IndiGo/LHT).
aviationregwatch.com publishes regulatory intelligence for aviation compliance professionals. This article is an informational summary compiled from the sources listed above, not legal or airworthiness advice. Verify against the primary source (FR doc. 2026-16954) before making compliance decisions. Consult your CAMO, engine MRO, or legal counsel for fleet-specific actions.
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