AD 91-18-18

final rule
Data completeness: 70%

Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes

AD Number
91-18-18
Status
final_rule
Effective Date
Product Category
aircraft
Docket
91-NM-175-AD
FR Citation
This information is not available.

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company DC-9-11 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-12 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-13 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-14 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-15 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-15F Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-21 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-31 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-32 Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes
aircraft The Boeing Company DC-9-32 (VC-9C) Airworthiness Directives; MCDONNELL DOUGLAS DC-9-10, -20, -30, -40, -50, and C-9 (Military) Series Airplanes

Unsafe Condition

Cracks in the fuselage left-hand skin panel at longeron 22L between stations 160 and 200 could cause rapid decompression of the pressurized fuselage.

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

Required Actions

Perform high frequency eddy current (HFEC) inspections at intervals not exceeding 1,500 landings. For airplanes with 55,000+ landings by AD effective date, inspect within 15 days after effective date. For those with fewer landings, inspect within 45 days or before 40,000 landings, whichever is later. Remove obscuring paint coatings if needed. Report findings within 10 days. Repair cracks before further flight if found.

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

Compliance Time

Required as indicated, unless previously accomplished.

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

Affected Aircraft

McDonnell Douglas DC-9-10, -20, -30, -40, -50, and C-9 (Military) 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

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