What happened
On June 25, 2023, at 15:13 local time, a SOCATA Rallye 235E, registration F-BXYS, was performing its second glider tow of the day at the Lillo aerodrome in Toledo, Spain. During the takeoff roll on runway 30, the aircraft's nose wheel detached at the moment of rotation. The glider pilot, notified of the mechanical failure, released the tow cable and landed safely on the runway.
The pilot of the F-BXYS performed a low-altitude pass over the runway threshold to confirm the status of the landing gear with ground witnesses. After confirming the nose wheel was missing, the pilot transitioned to a short right-hand circuit to land on runway 12. During the base leg of this maneuver, at an altitude of approximately 50 feet and a speed of 110 km/t, the pilot decided to shut off the fuel supply and the mixture to prevent sparks from the metal nose gear contacting the asphalt upon landing. This action caused the engine to stop almost immediately. Due to the high density altitude and the loss of engine power, the aircraft could not maintain enough glide performance to reach the runway, resulting in an emergency landing in an unprepared field on a private property. The aircraft struck a woodpile, causing significant damage to the airframe, propeller, and landing gear, though the pilot remained uninjured.
The investigation
Investigators examined the condition of the nose gear assembly and the maintenance history of the aircraft. The last 100-hour inspection, performed one month prior, had included checks of the wheel coupling and tire pressure with satisfactory results. Upon inspection of the remaining nose gear components, investigators found that the four bolts securing the wheel to the axle showed no signs of bending or deformation, but the threads were slightly crushed, suggesting that the four nuts had loosened and detached almost simultaneously. No traces of the missing nuts or washers were found on the runway.
The investigation also reviewed the pilot's flight path and the engine shutdown procedure. It was noted that the pilot executed a much tighter circuit than the procedures recommended by the local flying club. Furthermore, the high density altitude (calculated at 4700 ft) significantly reduced the aircraft's gliding capability once the engine was shut down.
Findings
- The primary cause of the accident was the landing on unprepared terrain due to the engine being shut down before the approach was stabilized.
- A contributing factor was the decision to shut down the engine during the base leg without having the landing assured.
- The loss of the nose wheel during takeoff was a contributing factor that initiated the sequence of events.
- The high density altitude significantly hindered the aircraft's ability to glide to the runway after the engine stopped.