Airworthiness Directives; De Havilland Aircraft of Canada Limited (Type Certificate Previously Held by Bombardier, Inc.) Airplanes
airworthiness · Rule · Final rule. · Published 2021-05-27 · Effective 2021-07-01 · 86 FR 28479
Document
Document number
2021-11088
Federal Register citation
86 FR 28479
Type
Rule
Action
Final rule.
Category
airworthiness
Manufacturer
De Havilland
Publication date
2021-05-27
Effective date
2021-07-01
FAA docket
Docket No. FAA-2021-0018
Abstract
The FAA is superseding Airworthiness Directive (AD) 2015-17- 08, which applied to certain Bombardier, Inc. Model DHC-8-400 series airplanes. AD 2015-17-08 required installing new cable assemblies with a pull-down resistor. This AD requires modifications to the nose wheel steering (NWS) system. This AD was prompted by a report indicating that several failure modes of the NWS system may cause the loss of feedback from both rotary variable differential transformers to the steering control unit. The FAA is issuing this AD to address the unsafe condition on these products.