Jan 10th 2025 : A Blue Islands Avions de Transport Régional ATR-72-212A suffered a serious electrical failure shortly after takeoff from Guernsey, forcing the crew to return to the departure airport using standby instruments only. The incident has been classified as a serious incident and is under investigation by the UK Air Accidents Investigation Branch (AAIB).
The aircraft, registration G-ISLM, was operating flight SI-208 from Guernsey to Jersey when the event occurred. While accelerating for takeoff and passing approximately 90 knots groundspeed, the aircraft’s transponder ceased transmitting. Despite the anomaly, the crew continued the takeoff and, shortly thereafter, elected to return to Guernsey.
According to the AAIB, shortly after becoming airborne the aircraft lost most of its electrical circuits along with all major flight instruments. The crew relied on standby instruments to safely navigate back to Guernsey, where the aircraft landed without further incident.
There were no injuries reported.
Aircraft Status
The ATR 72 has remained grounded in Guernsey since the occurrence and is still on the ground seven days later as technical inspections and the investigation continue.
AAIB Findings
The AAIB confirmed that the event has been rated a serious incident due to the significant loss of aircraft systems in flight. In a brief interim report released on January 9, 2026, investigators provided initial technical findings.
The AAIB stated:
“Examination of the electrical system components has identified the Starter/Generator fitted to the right engine as the source of the overvoltage which affected the aircraft, but the reason this overvoltage was not isolated by the safety systems fitted to the aircraft remains unclear.”
Investigators are now focusing on why the aircraft’s protective systems failed to isolate the overvoltage condition, allowing it to propagate through the electrical network and disable multiple systems.
Ongoing Investigation
The investigation remains ongoing and will examine the starter/generator unit, electrical protection architecture, and maintenance history of the aircraft. Further analysis will also assess crew actions and procedures during the loss of primary instruments, though the AAIB has already acknowledged the successful handling of the situation using standby systems.
The AAIB is expected to release additional findings once the technical examination is complete.
