What happened
On February 9, 2018, an Airbus EC 135 P2+ helicopter was undergoing scheduled hangar maintenance at Warsaw-Babice Airport (EPBC). The aircraft had reached the threshold for a major service interval after three years of operation or 1,000 flight hours. A technical support station team in Babice was executing tasks under work order 1/SOT HXD/2018.
At 13:37 local time, the crew performed a ground power check (GPC) to verify engine performance. During this procedure, which involved moving the helicopter while hovering close to the ground, both engines exceeded their allowable torque limits simultaneously. The left engine exceeded its limit by 90% for 0.750 seconds, and the right engine exceeded its limit by 89.5% for 0.625 seconds.
The pilot immediately halted further operations and reported the incident to the Technical Coordination Center. Following consultation with a duty engineer, aviation mechanics conducted a detailed inspection of the airframe and systems according to maintenance manual sections MSM 05-51-00 and 6-8 (categories A through D). No abnormalities were found during this inspection. The helicopter remained under technical supervision for continued maintenance.
The investigation
The PKBWL reviewed the operational data and the maintenance context. The incident occurred during a routine maintenance task rather than revenue flight operations. The investigation focused on whether the mechanical systems failed or if human error caused the excessive torque application.
Findings
The primary cause of the event was identified as improper attention distribution by the pilot while maneuvering the helicopter in a hover configuration. The excessive torque values were not due to mechanical failure but resulted from incorrect control inputs during the low-altitude movement required for the ground power check.
No safety recommendations were issued by the commission, as the operator addressed the issue internally through personnel briefing and operational review.
Safety action
The operating unit (LPR) discussed the incident with all operational personnel to reinforce proper procedures for maintenance-related hover maneuvers.