AD 77-21-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 527 | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 528-7E | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 528D-7E | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-7E | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-7H | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-8E | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-8H | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-8X | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-8Y | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
| engine | Rolls-Royce Deutschland Ltd & Co KG | Dart 529-8Z | ROLLS ROYCE AERO, LTD Models Dart 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 Series Engines |
Unsafe Condition
Overheating and failure of high pressure turbine discs due to cracking of the support legs of flame tube bridge pieces.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Within 500 hours engine time in service after the AD's effective date, inspect flame tube bridge pieces for support leg cracking per Rolls Royce Service Bulletin Da 72-420 or an FAA-approved equivalent. If cracking is found, replace the affected part before further flight (except for flights under FAR 21.197/199 to a base for repairs). Establish reduced inspection intervals for the fleet if cracking is detected during inspections.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 500 hours engine time in service after the effective date of this AD and thereafter at intervals not to exceed 1500 hours engine time in service
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Rolls-Royce Deutschland Ltd & Co KG Dart Engines Series 527, 528, 529, 531, 532, 533, 534, 535, 536, 550, 542-4, 542-10, and 543-10 with modification 1425 incorporated.
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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