# 2026-16157: FAA Targets Boeing 787s' Debris-Shy Engine Cowlings

2026-16157, Airworthiness Directives; The Boeing Company Airplanes, is a Federal Register proposed rule from Transportation Department, Federal Aviation Administration published 2026-08-07, effective The FAA must receive comments on this proposed AD by September 21, 2026.; PRIA reads it as touching household money (as of 2026-08-14).

- Canonical: https://policyrisk.com/federal-register/2026-16157
- As of: 2026-08-14
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2026-16157
- Title: Airworthiness Directives; The Boeing Company Airplanes
- Type: Proposed Rule
- Agencies: Transportation Department; Federal Aviation Administration
- Citation: 91 FR 51111
- Published: 2026-08-07
- Effective: The FAA must receive comments on this proposed AD by September 21, 2026.
- Comments close: 2026-09-21
- Significant: no
- Touches household money: yes
- Regulation identifier numbers: 2120-AA64
- Last updated: 2026-08-14

## In one line

FAA Targets Boeing 787s' Debris-Shy Engine Cowlings

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. This proposed AD was prompted by a report indicating that the protection system on the left fan cowl of the right engine does not sufficiently cover the components and systems from possible cross engine debris. This proposed AD would require performing a maintenance records check or inspection of the right engine to determine the part number of the left fan cowl and applicable on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products.

## Effects PRIA read

- Required inspection of right-engine fan cowl: benefit, medium. If you operate certain Boeing Model 787-8, 787-9, or 787-10 airplanes with Rolls Royce Trent 1000-AE3, -CE3, -D3, -G3, -H3, -J3, or -K3 engines, the FAA would require a maintenance records check or inspection of the right engine to determine the left fan cowl part number and do any on-condition act…
- Prohibition on installing certain fan cowl parts: cost, medium. As of the effective date of the AD, no person may install a right-engine left fan cowl with part numbers 725Z2300-307, 725Z2300-305, or 725Z2300-5003 on any airplane. This prohibition applies to the same Boeing Model 787 airplanes equipped with the listed Rolls Royce Trent 1000 engine models.
- Estimated inspection cost and U.S. fleet affected: cost, low. The FAA estimates this AD would affect 22 U.S.-registered airplanes and that a maintenance records check or inspection would cost 3 work-hours × $85 per hour = $255 per airplane, for a total estimated cost on U.S. operators of $5,610. Comments on the proposed AD are due by September 21, 2026.
- On-condition modification and replacement cost estimates: cost, medium. If the inspection finds affected parts, the FAA estimates on-condition modification of a fan cowl would cost about $5,226 per airplane (labor $510 and parts $4,716), and replacement is estimated at 2 work-hours × $85 = $170 labor per airplane (parts cost not definitively estimated). The FAA states…

## Related documents

- [2026-15585](https://policyrisk.com/federal-register/2026-15585): Requirements for Interference-Tolerant Radio Altimeter Systems, 2026-07-31
- [2026-13440](https://policyrisk.com/federal-register/2026-13440): Enabling Supersonic Overland Flight, 2026-07-02
- [2026-13126](https://policyrisk.com/federal-register/2026-13126): Designation-Restrict the Operation of Unmanned Aircraft in Close Proximity to a Fixed Site Facility; Extension of Comment Period, 2026-06-30
- [2026-08943](https://policyrisk.com/federal-register/2026-08943): Designation-Restrict the Operation of Unmanned Aircraft in Close Proximity to a Fixed Site Facility, 2026-05-06
- [2025-04846](https://policyrisk.com/federal-register/2025-04846): Extension of the Prohibition Against Certain Flights in the Territory and Airspace of Libya, 2025-03-20
- [2025-03853](https://policyrisk.com/federal-register/2025-03853): Enforcement Policy Regarding “Drug and Alcohol Testing of Certificated Repair Station Employees Located Outside of the United States; Corre…, 2025-03-11

## Sources
- [2026-16157 on federalregister.gov](https://www.federalregister.gov/documents/2026/08/07/2026-16157/airworthiness-directives-the-boeing-company-airplanes)
- [2026-16157 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2026-08-07/pdf/2026-16157.pdf)

## Related
- [Previous: 2026-16134, Reducing Federal Burden for Head Start Programs](https://policyrisk.com/federal-register/2026-16134)
- [Next: 2026-16196, Build America: Eliminating Barriers to Wireline Deployments](https://policyrisk.com/federal-register/2026-16196)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2026-16157 (as of 2026-08-14).