AD 2005-23-11
Unsafe Condition
Uncontained failures of compressor impeller assemblies in Hamilton Sundstrand Power Systems auxiliary power units (APUs) models T-62T-46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-46C7A, with compressor impeller assembly part numbers 4502020 or 4502020A installed.
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Required Actions
Remove compressor impeller assemblies from service before accumulating 500 additional cycles if they have 12,000 or more cycles-since-new (CSN) on the effective date. Remove compressor impeller assemblies from service at or before accumulating 12,500 CSN if they have fewer than 12,000 CSN on the effective date.
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Compliance Time
Within the specified compliance times based on cycles-since-new (CSN) as outlined in the AD.
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Affected Aircraft
Hamilton Sundstrand Power Systems auxiliary power units (APUs) models T-62T-46C2, T-62T-46C2A, T-62T-46C3, T-62T-46C7, and T-62T-46C7A, with compressor impeller assembly part numbers 4502020 or 4502020A installed. These APUs are installed on, but not limited to, BAE Systems AVRO 146, Fokker 50, Saab 2000, and Saab 340 airplanes.
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Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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