What aircraft was involved and where did it happen?

The accident on null involved a Comco Ikarus C42B, registration EI-ERM, at IE.

What was the probable cause of the accident?

The engine of the aircraft failed at a low altitude, necessitating a forced landing that resulted in significant damage to the airframe.

Engine Failure Leads to Forced Landing on Bartragh Island

A Comco Ikarus C42B aircraft experienced an engine cutout at low altitude, resulting in a forced landing on a beach in Co. Mayo with substantial damage.

What happened

On 3 January 2021, a Comco Ikarus C42B, registration EI-ERM, was performing a private flight from Sligo Airport to Belmullet Aerodrome. While flying at an altitude of approximately 600 to 700 feet near Bartragh Island, Co. Mayo, the engine suddenly failed. The pilot reported that the engine "chugged twice" before cutting out entirely during an attempt to increase power.

Following a single unsuccessful restart attempt, the pilot executed a forced landing on a sandy beach on the southwest side of the island. During the landing, the nose and right main landing gear collapsed and detached from the airframe. Despite the substantial damage to the aircraft, including a broken propeller blade and structural damage to the fuselage and wings, the pilot and one passenger escaped the aircraft without injury.

The investigation

The AAIU examined the aircraft at its recovery site and reviewed the pilot's flight history and maintenance records. The investigation focused on the engine's failure, specifically looking at the possibility of carburettor icing or vapour lock. Investigators noted that the aircraft was using MOGAS (automotive gasoline), which was found to have a higher-than-normal water content and high volatility.

Technical analysis also considered the state of the carburettor heat system. While some wear was noted on the flap spindle, it was not deemed a primary cause. The investigation also looked into the pilot's licensing, noting that the required prior notification to the Irish Aviation Authority for a UK-issued licence had not been received.

Findings

The engine failure occurred at a low altitude, leaving the pilot with very little time to diagnose the issue and select a landing site.
The aircraft was operating in weather conditions highly susceptible to carburettor icing.
The use of winter-grade MOGAS, characterized by high volatility and elevated water content, increased the risk of ice formation in the carburettor.
The pilot had turned the carburettor heat to the OFF position minutes before the engine failed.
Vapour lock within the fuel system, a known risk when using MOGAS, was identified as a potential contributing factor.