EASA SIB 2008-44
CASA Australia AWB 73-004 - Piston Engine Powered Helicopters - Malfunctioning of the Carburettor Accelerator Pump in the Fuel System
Summary
CASA Australia Airworthiness Bulletin AWB 73-004 is an advisory document addressing the malfunctioning of the carburettor accelerator pump in the fuel system of piston engine powered helicopters, specifically including the Robinson R44 Raven I. It highlights that difficulty in engine starting may indicate a faulty accelerator pump, which can cause engine hesitation or stoppage during critical flight maneuvers such as autorotation. The bulletin aims to inform operators and maintenance personnel to check the accelerator pump function during troubleshooting.
What Changed
This bulletin introduces an advisory to operators and maintenance personnel about the risks associated with a malfunctioning carburettor accelerator pump in piston engine helicopters. It emphasizes the importance of checking the accelerator pump when encountering engine starting difficulties to prevent engine hesitation or stoppage during flight. The document is a new safety information bulletin supported by EASA and CASA but does not impose mandatory requirements.
Why It Matters
The malfunction of the carburettor accelerator pump can lead to engine hesitation or stoppage during critical flight phases, such as rapid throttle application in autorotation, potentially causing loss of helicopter control. Early identification through engine starting difficulties allows for timely maintenance, improving flight safety and reliability. This information is crucial for operators, maintenance organizations, and compliance teams to ensure safe helicopter operation and avoid in-flight engine performance issues.
What To Do
Operators and maintenance personnel of piston engine powered helicopters, including the Robinson R44 Raven I, should check the proper function of the carburettor accelerator pump whenever engine starting difficulties occur. Troubleshooting should include inspection and verification of the accelerator pump to prevent unreliable engine performance. There is no mandatory compliance deadline, but prompt attention is recommended to maintain safety.
Your fleet's weekly compliance brief
AI-summarized regulatory changes, compliance deadlines, and action items — filtered to your aircraft, every Monday.
AI-generated summary from official EASA source document. Always verify against the original.