AD 2004-21-04
Unsafe Condition
Intermittent malfunctioning of the AR 4201 VHF AM transceiver, leading to difficulty in blocking interference from transmitters operating on frequencies other than those set in the transceiver.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the serial number (SN) of installed AR 4201 transceivers. If the SN is affected (0150 through 9499) and does not have Change Index 02 or higher, either add an AFM limitation restricting transceiver usage to VFR operations and install a cockpit placard, or remove the transceiver from service.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within five days after the effective date of the AD (November 19, 2004).
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Affected Aircraft
Becker Flugfunkwerk GmbH AR 4201 VHF AM transceivers with serial numbers 0150 through 9499.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 6, 2026
Rights: U.S. Government Public Domain
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