AD 2009-12-05

final rule
Data completeness: 80%

Airworthiness Directives; Boeing Model 737-300, -400, and -500 Series Airplanes

AD Number
2009-12-05
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2008-1364
FR Citation
74 FR 27691

Applicability

TypeManufacturerModelDetails
aircraft Boeing 737-300 Airworthiness Directives; Boeing Model 737-300, -400, and -500 Series Airplanes

Unsafe Condition

Loss of both the normal electronic flight instrument system (EFIS) cooling supply and the indication of EFIS cooling loss due to a single failure of the battery bus, causing eventual power-down of the EFIS displays.

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

Required Actions

Modify the control power wiring of the normal supply fan and the low flow sensor for the equipment cooling system of the electronic flight instrument system (EFIS).

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

Compliance Time

Within a specified time frame (not explicitly stated in the provided text).

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

Affected Aircraft

Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-21A1156, Revision 2, dated December 11, 2008.

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

Source: Official FAA Source ↗

Retrieved: Apr 4, 2026

Rights: U.S. Government Public Domain

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