# Proposed AD FAA-2023-1404: Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2023-21-12
- Products: MHI RJ Aviation ULC
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: July 12, 2023, 88 FR 44226
- Comments due: August 28, 2023
- Became: [AD 2023-21-12](https://openairdocs.org/ad/2023-21-12)
- Docket: FAA-2023-1404 (https://www.regulations.gov/docket/FAA-2023-1404, where comments are filed)
- Project: MCAI-2023-00451-T
- FR document: 2023-14616
- Official PDF: https://openairdocs.org/files/sha256/0f/eb/0febed98550a8488516a312abd0ab8c88ac46c71235311c40a1fcc95ffc26d3e (from https://www.govinfo.gov/content/pkg/FR-2023-07-12/pdf/2023-14616.pdf)
- Federal Register: https://www.federalregister.gov/documents/2023/07/12/2023-14616/airworthiness-directives-airworthiness-directives-mhi-rj-aviation-ulc-type-certificate-previously
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADNPRM-2023-14616-00000000000.0001
- Page: https://openairdocs.org/proposed/FAA-2023-1404

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for all MHI RJ Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This proposed AD was prompted by a report of missing insulation in the engine pylon area. This proposed AD would require, for certain airplanes, inspecting the engine pylon structure for discrepancies and repair if necessary. This proposed AD would also require revising the existing maintenance or inspection program, as applicable, to incorporate a new certification maintenance requirement (CMR) task. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Jul 12, 2023: Notice of proposed rulemaking (NPRM). (first notice), FR document 2023-14616, comments due Aug 28, 2023 (https://www.federalregister.gov/documents/2023/07/12/2023-14616/airworthiness-directives-airworthiness-directives-mhi-rj-aviation-ulc-type-certificate-previously)

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