Airworthiness Directive 98-04-13
one-timeAirworthiness Directives; Rolls-Royce Limited Dart Series Turboprop Engines
What this AD requires
This amendment supersedes an existing airworthiness directive (AD), applicable to Rolls-Royce Limited (R-R) Dart series turboprop engines, that currently establishes a life limit for propeller low torque switches. This amendment adds two propeller low torque switch part numbers and two R-R Dart engine models that were omitted from the current AD, and establishes a calendar end-date for removal of propeller low torque switches from service. This amendment is prompted by the need to add omitted part numbers and engine models to the AD. The actions specified by this AD are intended to prevent cracking of the snap diaphragm in the propeller low torque switch, which could delay propeller auto-feathering and thereby adversely affect aircraft controllability.
Which aircraft AD 98-04-13 applies to
Installed on but not limited to Gulfstream Aerospace G-159, British Aerospace HS 748, Fokker F.27, Mitsubishi Heavy Industries YS-11, General Dynamics (Convair) 580 and 600 series, and Vickers Armstrongs Viscount aircraft. AD notes clarify some designations were revised between NPRM and final rule (e.g., Mk. 511 to Mk. 511 series) and that Mk. 515, 520, 533, 534, 536, and 543 were removed as not U.S.-validated.
Whether AD 98-04-13 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.