AD 99-21-27

final rule
Data completeness: 70%

Airworthiness Directives; Bombardier Model DHC-8-311 and -315 Series Airplanes

AD Number
99-21-27
Status
final_rule
Effective Date
Product Category
aircraft
Docket
98-NM-324-AD
FR Citation
Federal Register: October 18, 1999 (Volume 64, Number 200)

Applicability

TypeManufacturerModelDetails
aircraft Bombardier Inc. DHC-8-311 Airworthiness Directives; Bombardier Model DHC-8-311 and -315 Series Airplanes
aircraft Bombardier Inc. DHC-8-315 Airworthiness Directives; Bombardier Model DHC-8-311 and -315 Series Airplanes

Unsafe Condition

Failure of the ditching dams to inflate fully during an emergency water landing, which could result in water entering the airplane.

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

Required Actions

Replace the existing nitrogen cylinder assembly on the ditching dams with a new assembly incorporating an improved valve assembly per Service Bulletin S.B. 8-25-122. Do not install nitrogen cylinder assemblies with part numbers 410870(BSC) or 410870-1.

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

Compliance Time

Within 6 months after the effective date of this AD for airplanes not covered in paragraph (a). For those in paragraph (a), within 6 months after July 8, 1998.

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Affected Aircraft

Bombardier Model DHC-8-311 and -315 series airplanes in medium and high gross weight configuration with specific Bombardier Change Requests incorporated.

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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