What happened
On the evening of 23 April 2001, a Bell UH-IE helicopter, registration N454CC, departed from a private helipad near the West Link Bridge in Dublin. The aircraft was conducting a private VFR flight toward Howth. After being cleared to proceed at 1,000 ft AMSL, the helicopter was transiting the area near Phoenix Park when the pilot noticed the engine low oil pressure caution light illuminate.
In response to the warning, the pilot reduced the collective pitch and notified Air Traffic Control of the intention to land. To avoid the security complications of landing in a public park, the pilot opted to perform a precautionary landing under power at the large tarmac square within McKee Barracks. The landing was completed successfully with no injuries and no damage to the aircraft or property.
The investigation
Investigators examined the engine components to identify the source of the pressure drop. Maintenance personnel discovered a crack in the engine oil return line where it connected to the oil tank at the firewall flange. This fracture had allowed pressurized oil to escape, resulting in a loss of fluid. Following the incident, the owner's maintenance team repaired the pipe and subsequently replaced the entire tube assembly with a flexible version, also replacing all related piping near the bulkhead.
Additionally, the investigation reviewed the flight path and the aircraft's operating limitations. The Bell UH-IE was operating under a US FAA Special Airworthiness Certificate in the Restricted Category, which prohibits operations over densely populated areas except for brief periods during takeoff and landing. The investigation noted that the planned route toward Howth would have taken the aircraft over several built-up areas of Dublin, which did not comply with these specific operating limitations.