EASA SIB 2009-12: Boeing 737 Erroneous Low Range Radio Altimeter (LRRA) indications | RegNotify

Safety Information BulletinEASA SIB 2009-12

Boeing 737 Erroneous Low Range Radio Altimeter (LRRA) indications

Published: Apr 30, 2009

Boeing 737

AI-generated summary of the official EASA document. Verify against the PDF before acting.

What to do

Flight crews should closely monitor primary flight instruments and flight mode annunciations, maintain hands-on throttle control when autothrottle is engaged during critical phases, and reduce automation levels if abnormal behavior is detected. Any occurrences of erroneous data should be reported to maintenance promptly. No mandatory compliance deadlines are specified.

Summary

EASA Safety Information Bulletin SIB No: 2009-12 addresses erroneous Low Range Radio Altimeter (LRRA) indications on Boeing 737 aircraft, specifically linked to the 737-800 model. The bulletin highlights issues with LRRA data affecting flight deck systems such as autothrottle, autopilots, and configuration warnings during critical flight phases. It provides information on the symptoms and operational impacts of these erroneous indications.

What changed

This bulletin introduces awareness of the erroneous LRRA indications affecting Boeing 737 aircraft and outlines the associated flight deck effects and abnormal system behaviors. It does not mandate changes but offers guidance and recommendations for flight crews to manage and mitigate the risks during flight operations.

Why it matters

Erroneous LRRA indications can lead to inappropriate autothrottle behavior, autopilot engagement issues, and unexpected warnings, potentially compromising flight safety during critical phases such as approach and go-around. Understanding these issues helps operators, maintenance teams, and flight crews maintain situational awareness and ensure safe aircraft operation despite automation anomalies.

More for Boeing 737

All 175

Get the next one by email

New ADs and bulletins for Boeing 737, summarized like this page, every Monday.