AD 2009-25-05
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Bombardier | DHC-8-400 | Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes |
| aircraft | Aviat | Various | Airworthiness Directives; Bombardier Model DHC-8-400 Series Airplanes |
Unsafe Condition
Internal contamination of the Lift/Dump (L/D) valve and moisture ingress into the L/D valve armature can cause inadvertent single spoiler deployment during flight.
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Required Actions
Inspect and incorporate Bombardier Modsum 4-113554 to add a filter/restrictor fitting to the spoiler lift dump valve, in accordance with Bombardier Service Bulletin 84-27-43.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 5,000 flight hours after the effective date of this AD.
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Affected Aircraft
Bombardier Model DHC-8-400, DHC-8-401, and DHC-8-402 series airplanes, serial numbers 4001 through 4237 inclusive.
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Source: Official FAA Source ↗
Retrieved: Apr 4, 2026
Rights: U.S. Government Public Domain
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