Flight AY-489 | Registration: OH-ATN
Date: 7 April 2025 | Location: Helsinki-Vantaa Airport (EFHK), Finland
Flight Details
• Aircraft Type: ATR-72-212A
• Engines: 2 × Pratt & Whitney PW127M turboprops
• Operator: Nordic Regional Airlines (NORRA) on behalf of Finnair
• Registration: OH-ATN
• Flight Number: AY-489
• Callsign: FIN489
• Route: Helsinki-Vantaa (EFHK) to Kuusamo (EFKS), Finland
• Date of Incident: 7 April 2025
• Total Occupants: 72 (66 passengers, 6 crew)
• Weather Conditions: VMC, dry runway, no reported windshear
Introduction
On 7 April 2025, an ATR-72-212A operated by Nordic Regional Airlines (NORRA) on behalf of Finnair aborted its take-off roll at Helsinki Airport due to a sudden drop in engine oil pressure. The aircraft, registered OH-ATN, was performing flight AY-489 to Kuusamo when the crew initiated a rejected take-off on runway 04R. The aircraft safely vacated the runway and taxied clear without further issue. No injuries were reported, and passengers were later transferred to a replacement aircraft.
Sequence of Events
Flight AY-489 was cleared for take-off from runway 04R at Helsinki-Vantaa in the late morning. During the initial phase of the take-off roll—prior to reaching decision speed—the crew detected a drop in oil pressure from one of the engines, most likely through cockpit engine instrumentation and ECAM alerts.
The captain initiated a rejected take-off, bringing the aircraft to a safe and controlled stop on the runway. The aircraft vacated the runway approximately 0.5 nautical miles down the surface, using a high-speed turnoff taxiway.
ATC was promptly informed, and runway operations resumed shortly thereafter with minimal disruption.
The aircraft taxied under its own power to a stand, where engineers began technical evaluation of the suspected engine lubrication fault. A replacement aircraft, OH-ATF, was dispatched and reached Kuusamo with a delay of approximately 1 hour and 40 minutes.
Crew & Communication
The flight crew made a timely and calculated decision to reject the take-off, likely informed by an engine parameter exceeding prescribed limits. The aircraft was still well below V1 (take-off decision speed), meaning the crew was legally and operationally permitted to abort.
Communications with ATC were clear and efficient. The crew informed passengers post-event of the oil pressure issue via PA announcement. The cockpit’s quick response avoided any further escalation or risk to safety.
Cabin crew remained seated during the incident and provided passenger reassurance following the rejected take-off.
Aircraft Systems & Technical Analysis
The ATR-72’s engine oil pressure system is monitored via cockpit gauges and warning lights linked to each engine’s lubrication system. A drop in pressure below safe operating limits typically results in an amber or red engine alert, accompanied by ECAM advisory messages or master caution triggers.
The ATR’s PW127M turboprop engine relies on a continuous supply of oil for bearing lubrication and propeller gearbox operation. Any deviation from the expected oil pressure could indicate:
• Oil pump malfunction
• Oil leak within the engine casing or reservoir
• Pressure sensor failure or erroneous reading
• Contamination or blockage in the lubrication system
• Thermal degradation causing oil thinning and loss of pressure
Upon inspection, maintenance teams would have prioritised:
• Engine oil level and integrity checks
• Sensor diagnostics
• Oil pump function tests
• Filter and line examination
• Engine log data and fault code analysis
The six-hour grounding suggests either a need for parts replacement or extended monitoring post-reset.
Passenger Experience & Cabin Conditions
Passengers felt a rapid deceleration on the runway but no abrupt movements or emergency braking. The atmosphere in the cabin remained calm, with most passengers unaware of the specific cause until after the aircraft had vacated the runway.
A passenger later reported that the crew announced an oil pressure drop as the reason for the rejected take-off. No emergency response was required, and disembarkation was routine once the aircraft reached the stand.
Passengers were rebooked onto a replacement ATR-72 (OH-ATF), which departed shortly after and arrived in Kuusamo with a delay of just over 100 minutes.
Emergency Response & Aftermath
Airport operations were not significantly impacted. There was no runway closure, and the aircraft cleared the active surface quickly. Fire and rescue services were not deployed, indicating that the situation remained under control throughout.
Finnair’s maintenance division began diagnostics immediately upon arrival at the stand. OH-ATN was removed from active duty and remains grounded as of the last update, roughly six hours post-incident.
The operator released a short statement confirming a technical malfunction and reiterated the importance of safety-driven decision-making.
Investigation Status
The incident is being treated as an operational technical event. No official investigation by Finnish aviation authorities has been announced, as the aircraft remained under full control and no safety breaches occurred.
An internal engineering report will determine the exact cause of the oil pressure anomaly, and findings will be shared with ATR and Pratt & Whitney if any component-level defect is confirmed.
All data from the aircraft’s digital flight recorder and engine health monitoring system will be used to support diagnostics.
Root Cause & Contributing Factors
The root cause is likely an abnormality in the oil pressure system of one engine. This could involve:
• Sudden mechanical fault within the oil pump
• Line or reservoir blockage
• Oil leak from seals or internal components
• Sensor malfunction giving a false pressure drop reading
Contributing factors may include recent maintenance activity, oil condition degradation, or operational temperature extremes that altered oil viscosity.
The crew’s rapid detection and decision-making prevented further engine strain and ensured that the aircraft remained serviceable for post-flight diagnostics.
Safety Recommendations & Industry Impact
While this was a routine technical rejection, the event reinforces key operational lessons:
• Importance of continuous engine parameter monitoring during take-off
• Early recognition and adherence to SOPs when mechanical limits are approached
• Emphasis on high-fidelity engine health monitoring systems
The operator may consider additional training scenarios involving slow-developing or minor engine faults during the take-off phase. If oil system component faults are confirmed, service bulletins or maintenance advisory notes may be issued to other ATR operators.
Conclusion
The rejected take-off of NORRA flight AY-489 at Helsinki was a textbook example of how swift cockpit decision-making and robust engine monitoring can prevent a minor fault from escalating into a major emergency. The crew’s prompt action ensured a safe outcome, and the airline’s recovery response minimised impact on passengers.
This incident highlights the continued importance of vigilance during all phases of flight, especially during high-stakes moments such as take-off acceleration.
Disclaimer
This article is based on publicly available information and reports at the time of writing. While every effort has been made to ensure accuracy, we cannot guarantee the completeness of the information provided.
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