AD 71-21-10
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Microdot | Cockpit Voice Recorder | Airworthiness Directives; MICRODOT, INC.: Applies to all Civil Aircraft Certificated in all Categories in Which A Microdot, Inc. Model 1410 Cockpit Voice Recorder is Installed |
Unsafe Condition
Inadvertent visual test circuit light illumination and reliance by flight crew members thereon.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Remove the test light bulb from the CVR Control Unit and install a placard stating 'TEST LIGHT INOPERATIVE'. Perform a daily aural functional test using a 600 ohm headset, checking for satisfactory speech reproduction after a one-second delay. Replace the bulb and remove the placard once Microdot Service Bulletin No. 4-A or equivalent modification is installed.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within five days of the effective date of this AD
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
All civil aircraft certificated in all categories in which a Microdot, Inc. Model 1410 Cockpit Voice Recorder is installed.
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
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.