RuAviation

The PD-8 turbofan engine has successfully completed bird ingestion tests at the open-air test facility of UEC-Saturn in Rybinsk. The trials evaluated engine operability following ingestion of small and medium-size birds. According to United Engine Corporation (UEC), the powerplant demonstrated stable operation and maintained flight safety margins in abnormal conditions.

Test Objectives and Methodology

According to Andrey Abrosimov, Head of the Test Cell Production Section at UEC-Saturn, each test involved the ingestion of four birds weighing 700–730 g (1.5–1.6 lb) each. The purpose of the trials was to assess engine response to bird ingestion events during critical phases of flight, including takeoff and landing.

“The key success criterion is correct engine control system response,” Abrosimov said. “If thrust reduction occurs, it must remain within specified limits, and the engine must automatically recover thrust to the commanded setting without crew intervention.”

Test Conditions

During the tests, the engine was operated at maximum takeoff power, producing approximately 78.5 kN (17,600 lbf) of thrust. A four-barrel bird launcher was positioned five meters (16.4 ft) from the nacelle and discharged four bird carcasses within one second. The launch parameters simulated aircraft true airspeed during takeoff and landing, approximately 103 m/s (200 kt).

Fan Module Assessment

The PD-8 high-bypass turbofan features a 24-blade fan stage. Birds were targeted at the most critical blade sections and the fan spinner to evaluate structural integrity and transient engine behavior under near-real operating conditions. For post-test inspection and visual analysis, the fan blades were painted yellow and marked with a dedicated measurement grid.

Certification Progress

Alexey Veretennikov, Deputy Chief Designer for Testing at UEC-Saturn, stated that the successful bird ingestion trial validates another requirement within the engine’s certification basis.

“The engine met the applicable bird ingestion requirement and demonstrated the required level of robustness,” he said. “This confirms the reliability of the PD-8 design.”

Sergey Mosin, Deputy Chief Designer responsible for nacelle design and aircraft integration, emphasized that the primary acceptance criterion is the absence of structural damage and preservation of engine functionality.

“Under simulated abnormal conditions, the PD-8 sustained no mechanical damage and remained fully controllable,” Mosin said. “The results confirm that encounters with bird flocks during real-world operations do not pose a hazard to the engine, which continues stable operation.”

Ongoing Test Program

The PD-8 engine is currently undergoing a comprehensive program of bench and flight tests as part of its certification campaign. These activities aim to validate declared performance characteristics and confirm the correctness of engineering solutions across the full operating envelope.

Previously, UEC-Saturn conducted certification tests involving fan blade-off events and water ingestion on the same open test stand. In both cases, the engine maintained operability under critical conditions. The PD-8 fan blades are manufactured from titanium alloys, providing the required strength and resistance to impact loads caused by foreign object damage (FOD).

In addition, the engine has demonstrated compliance with regulatory requirements during acoustic testing, crosswind operation trials, and thrust reverser evaluations. The collected data are being used to refine engine parameters and complete the PD-8 certification cycle as part of the SJ-100 (Superjet 100) aircraft program.