AD 86-25-03

final rule
Data completeness: 70%

Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes

AD Number
86-25-03
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Unknown
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft Bombardier Inc. | Viking Air Limited DHC-8-101 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-102 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-103 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-106 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-201 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-202 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-301 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-311 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-8-315 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes
aircraft Bombardier Inc. | Viking Air Limited DHC-7-1 Airworthiness Directives; DeHavilland Model DHC-7 and DHC-8 Series Airplanes

Unsafe Condition

Accumulated water freezing in the elevator trim-tab jack-screw housing could cause the elevator trim-tab to become inoperable.

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

Required Actions

Incorporate de Havilland Modification Numbers 7/2489 (for DHC-7) or 8/0415 (for DHC-8) to provide a drain hole in the elevator trim-tab jack-screw housing, following the instructions in the respective service bulletins.

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

Compliance Time

within three months after the effective date of this AD

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

Affected Aircraft

De Havilland Model DHC-7 and DHC-8 series airplanes, certificated in any category.

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

This site is not affiliated with or endorsed by the FAA. Always verify with official sources.