AD 98-23-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Parker Hannifin Corporation | Dry Air Pumps | Airworthiness Directives; Parker Hannifan Airborne Dry Air Pumps, Conversion Kits, and Coupling Kits |
| aircraft | Parker Hannifin Corporation | Conversion Kit | Airworthiness Directives; Parker Hannifan Airborne Dry Air Pumps, Conversion Kits, and Coupling Kits |
| aircraft | Parker Hannifin Corporation | Coupling Kit | Airworthiness Directives; Parker Hannifan Airborne Dry Air Pumps, Conversion Kits, and Coupling Kits |
Unsafe Condition
Failure of the flexible coupling P/N B1-19-1 due to a manufacturing defect, which could result in loss of primary attitude and direction references during instrument flight rules (IFR) operations.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Replace the affected flexible coupling P/N B1-19-1 with P/N B1-7-3 flexible coupling (part of Airborne P/N 350 coupling kit) in accordance with Parker Hannifin Service Letter No. 48. This includes removing the dry air pump, inspecting/identifying the defective coupling, and installing the replacement coupling.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Effective November 20, 1998, except for those to whom it was made immediately effective by priority letter AD 98-23-01 issued October 29, 1998.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Parker Hannifin Corporation dry air pumps, conversion kits, and coupling kits with P/N B1-19-1 flexible coupling having date codes '12/97' or '5-6/98', installed in aircraft models listed in the AD's Appendix, including specific part numbers and serial ranges like 211CC (2AP1-10AP319), 211CC-9 (1AP1-2AP5), and E211CC (11AN543).
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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