AD 98-16-15

final rule
Data completeness: 70%

Airworthiness Directives; British Aerospace Model B.121 Series 1, 2, and 3 Airplanes

AD Number
98-16-15
Status
final_rule
Effective Date
Product Category
aircraft
Docket
98-CE-03-AD
FR Citation
Federal Register: August 7, 1998 (Volume 63, Number 152)

Applicability

TypeManufacturerModelDetails
aircraft DeHavilland Support Limited Beagle B.121 Series 1 Airworthiness Directives; British Aerospace Model B.121 Series 1, 2, and 3 Airplanes
aircraft DeHavilland Support Limited Beagle B.121 Series 2 Airworthiness Directives; British Aerospace Model B.121 Series 1, 2, and 3 Airplanes
aircraft DeHavilland Support Limited Beagle B.121 Series 3 Airworthiness Directives; British Aerospace Model B.121 Series 1, 2, and 3 Airplanes

Unsafe Condition

Structural failure of the main spar web area caused by fatigue cracking or separation of the wing caused by loose nuts at the wing to fuselage main-spar attachment fittings, which could result in loss of control of the airplane.

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

Required Actions

Replace the nuts with improved design nuts at the wing to fuselage main-spar attachment fittings. Install an inspection opening and inspect the main spar web area using eddy current methods for cracks. Repair or replace any cracked parts.

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

Compliance Time

Within the next 100 hours time-in-service (TIS) after the effective date of this AD for nut replacement. Upon accumulating 2,000 hours TIS on the main spar or within the next 50 hours TIS after the effective date of this AD, whichever occurs later, for inspection opening installation and initial inspection.

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

Affected Aircraft

British Aerospace Model B.121 Series 1, 2, and 3 airplanes, all 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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