AD 93-25-02

final rule
Data completeness: 70%

Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes

AD Number
93-25-02
Status
final_rule
Effective Date
Product Category
aircraft
Docket
90-NM-129-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Bombardier Inc. DHC-8-101 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes
aircraft Bombardier Inc. DHC-8-102 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes
aircraft Bombardier Inc. DHC-8-103 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes
aircraft Bombardier Inc. DHC-8-106 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes
aircraft Bombardier Inc. DHC-8-301 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes
aircraft Bombardier Inc. DHC-8-311 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes
aircraft Bombardier Inc. DHC-8-315 Airworthiness Directives; De Havilland Models DHC-8-100 and DHC-8-300 Series Airplanes

Unsafe Condition

Cracks in the splined couplings of flap primary-drive torque tubes could cause asymmetrical flap deployment.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect flap primary-drive torque tubes for specific part numbers and serial numbers listed in TABLE 1. If installed, remove through-bolts and inspect for cracks using a 10X magnifying glass. Replace cracked splined couplings or torque tubes as specified in Sundstrand Service Bulletins. Conduct recurring inspections at intervals not exceeding 300 hours time-in-service. Perform operational checks of torque sensors and install specified modifications within 2,000 hours time-in-service or 9 months.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 300 hours time-in-service after January 19, 1994, and recurring intervals as specified.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Bombardier Inc. models DHC-8-101, DHC-8-102, DHC-8-103, DHC-8-106, DHC-8-301, DHC-8-311, DHC-8-315 with serial numbers 3 through 293.

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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