AD 87-11-08 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | ATR - GIE Avions de Transport R gional | ATR42-200 | Airworthiness Directives; AEROSPATIALE Model ATR-42 Series Airplanes |
| aircraft | ATR - GIE Avions de Transport R gional | ATR42-300 | Airworthiness Directives; AEROSPATIALE Model ATR-42 Series Airplanes |
| aircraft | ATR - GIE Avions de Transport R gional | ATR42-320 | Airworthiness Directives; AEROSPATIALE Model ATR-42 Series Airplanes |
| aircraft | ATR - GIE Avions de Transport R gional | ATR42-500 | Airworthiness Directives; AEROSPATIALE Model ATR-42 Series Airplanes |
Unsafe Condition
Simultaneous loss of both pilots' primary attitude and heading information generated by Attitude and Heading Reference Systems (AHRS).
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Isolate pilots' AHRS (AHRS Number 1) from the System Avionics Standard Communications Bus (ASCB) per Service Bulletin ATR-42-34A-0016, install EFIS Symbol Generators with part number 700544-411, Mod-level U or subsequent, insert specified limitations into the AFM and FCOM, replace AHRS with modified units per Service Bulletin ATR42-34-340018, and connect four wires between terminal blade 67VT1 and connector 1FP1-AA. Alternate compliance may be approved by the FAA Manager, Standardization Branch.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within 15 days after June 8, 1987 (the effective date of Amendment 39-5628, AD 87-11-08), unless previously accomplished.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
AEROSPATIALE Model ATR-42 series airplanes, including ATR42-200, ATR42-300, ATR42-320, ATR42-500, certificated in any category, unless the equivalent of Production Modification 1397 was installed prior to delivery.
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.