# Proposed AD FAA-2020-0975: De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2021-11-04
- Products: De Havilland Aircraft of Canada
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: November 2, 2020, 85 FR 69276
- Comments due: December 17, 2020
- Became: [AD 2021-11-04](https://openairdocs.org/ad/2021-11-04)
- Docket: FAA-2020-0975 (https://www.regulations.gov/docket/FAA-2020-0975, where comments are filed)
- FR document: 2020-24040
- Official PDF: https://openairdocs.org/files/sha256/bf/9d/bf9d92b2409fd2d46c30f81ec88ad4dfa736bc9e347efcf65b356cb5e0eab528 (from https://www.govinfo.gov/content/pkg/FR-2020-11-02/pdf/2020-24040.pdf)
- Federal Register: https://www.federalregister.gov/documents/2020/11/02/2020-24040/airworthiness-directives-de-havilland-aircraft-of-canada-limited-type-certificate-previously-held-by
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/86B931B4A5C605208625861400535AB9.0001
- Page: https://openairdocs.org/proposed/FAA-2020-0975

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain De Havilland Aircraft of Canada Limited Model DHC-8-400, - 401, and -402 airplanes. This proposed AD was prompted by a report of main landing gear (MLG) retractions after striking an obstacle or severe wheel imbalance after a tire failure. This proposed AD would require inspections for correct height of the lock link over-center stop pin and for correct gaps of the left-hand and right-hand MLG downlock proximity sensors, replacement of the shim if necessary, and corrective actions, and installation of a new improved proximity sensor electronic unit (PSEU) with software changes. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Nov 2, 2020: Notice of proposed rulemaking (NPRM). (first notice), FR document 2020-24040, comments due Dec 17, 2020 (https://www.federalregister.gov/documents/2020/11/02/2020-24040/airworthiness-directives-de-havilland-aircraft-of-canada-limited-type-certificate-previously-held-by)

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