AD 78-10-04
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Airesearch | Auxiliary Power Units | Airworthiness Directives; AIRESEARCH MANUFACTURING COMPANY OF ARIZONA: Applies to AiResearch Model TSCP700-4B and -5 Auxiliary Power Units (APU's) |
Unsafe Condition
High energy release of first stage compressor blades and disk parts due to possible fatigue failure of the disk.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove the first stage disk from the compressor section of the APU and replace with a like serviceable part. Operators must track cycles using defined parameters, including cycle definitions and approved ratios for unrecorded data.
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Compliance Time
Before accumulating a total of more than 3000 cycles on the first stage compressor disks, or within the next 300 cycles after the effective date of this AD, whichever occurs later.
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Affected Aircraft
AiResearch Model TSCP700-4B and -5 Auxiliary Power Units (APU's) with first stage compressor disks P/N's 969600-1 or -2 and the listed serial numbers.
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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