What happened
During the takeoff roll, as the aircraft reached rotation speed, the flight crew was alerted by a fire bell and the illumination of the number two engine fire warning light. Simultaneously, they observed a loss of power on that specific engine. Rather than aborting the takeoff, the crew continued the departure to ensure sufficient altitude for emergency procedures. They successfully secured the affected engine and discharged both fire extinguisher bottles into the engine pylon. Despite these actions, the fire persisted within the engine compartment.
The aircraft remained airborne and circled in the pattern to burn off excess fuel and allow systems to cool. The crew executed a normal approach and landing at the departure airport. During this overweight landing, the brake system experienced significant overheating due to the high kinetic energy of the aircraft. However, there was no structural damage to the airframe beyond the engine compartment, and no injuries were reported among the passengers or crew.
The investigation
Following the incident, a detailed teardown and inspection of the number two engine were conducted to determine the root cause of the fire. The examination focused on the high-pressure compressor (HPC) section. Forensic analysis revealed that a single compressor blade had separated from the sixth stage of the HPC rotor.
The investigation determined that the blade failure originated from fatigue cracking in the dovetail area, which is the attachment point securing the blade to the rotor disk. Once the first blade detached, it caused cascading damage to the seventh stage and all remaining stages of the compressor. The high-energy debris impacted the titanium engine case, igniting a fire within the engine compartment.
Findings
The primary finding was that a fatigue failure initiated at the dovetail of a sixth-stage compressor blade on the number two engine's high-pressure compressor rotor. This mechanical separation led to internal engine damage and a subsequent titanium case fire. Contributing factors included the overweight condition of the aircraft upon landing, which necessitated heavy braking and resulted in brake overheating, though this did not compromise safety.
Safety message
This incident highlights the critical importance of continued takeoff procedures when an engine failure occurs near rotation speed. By continuing the flight rather than aborting at high speed, the crew ensured adequate altitude to manage the emergency safely. It also underscores the need for rigorous maintenance protocols to detect early signs of fatigue in compressor blade dovetails before catastrophic separation occurs.