AD 98-04-13
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 506 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 510 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 511 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 511-7E | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 514 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 514-7 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 525 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 525F | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 526 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 527 | Airworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines |
Unsafe Condition
Cracking of the snap diaphragm in the propeller low torque switch could delay propeller auto-feathering and adversely affect aircraft controllability.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove from service propeller low torque switches with specific part numbers based on their accumulated calendar years time in service (TIS), replacing them with serviceable parts. Actions include removal within 30 days after the AD's effective date for switches with 5+ years TIS, within 5 years TIS or 30 days after effective date (whichever is later) for those with less than 5 years TIS, and immediate replacement if TIS cannot be established. New/overhauled switches must be removed at or before 5 calendar years TIS since installation.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 30 days after the effective date of this AD (March 24, 1998) for certain conditions, or within 5 calendar years total TIS, whichever occurs later. New/overhauled switches must comply at or prior to 5 calendar years TIS since installation.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Rolls-Royce Limited Dart Mk. 506, 510, 511 series, 514 series, 525 series, 526, 527, 528 series, 529 series, 530, 531, 532 series, 535 series, 542 series, 551 series, and 552 series turboprop engines installed on specified aircraft models.
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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