AD 2002-23-18

final rule
Data completeness: 70%

Airworthiness Directives; McDonnell Douglas Model MD-11 and -11F Airplanes Equipped with Collins LRA-900 Radio Altimeters

AD Number
2002-23-18
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 2000-NM-406-AD
FR Citation
67 FR 70678

Applicability

TypeManufacturerModelDetails
aircraft McDonnell Douglas MD-11 and -11F Airworthiness Directives; McDonnell Douglas Model MD-11 and -11F Airplanes Equipped with Collins LRA-900 Radio Altimeters

Unsafe Condition

A fault in Collins LRA-900 radio altimeters having a certain part number could result in an incorrect and unbounded output of radio altitude to other airplanes, leading to an undetected anomalous radio altitude signal passed to the flare control law of the flight control computer, which could cause the airplane to flare too high or too low during landing, and consequently result in a hard landing.

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Required Actions

Revise the Limitations Section of the FAA-approved Airplane Flight Manual to prohibit autopilot coupled autoland operations below 100 feet above ground level (AGL). Alternatively, replace both Collins LRA-900 radio altimeters having part number 822-0334-220 with Collins LRA-700 radio altimeters having part number 622-4542-221. Perform a one-time general visual inspection to determine the part number of the radio altimeter receiver/transmitters.

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Compliance Time

Within 90 days after the effective date of this AD.

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Affected Aircraft

McDonnell Douglas Model MD-11 and -11F airplanes equipped with certain Collins LRA-900 radio altimeters.

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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