What happened
On December 29, 2017, at 17:30 UTC, a Cessna 510, registration PP-WGS, was performing a private flight from Jundiaí, SP, to Ubatuba, SP. The aircraft was carrying one pilot and three passengers. Upon landing at Ubatuba Aerodrome (SDUB), the aircraft exceeded the longitudinal limit of the runway and performed an approximately 230-degree anti-clockwise turn on the grass area. The aircraft came to a complete stop 43 meters beyond the runway end. The aircraft sustained light damage, but all four occupants were uninjured.
The investigation
The investigation by CENIPA examined the operational conditions at SDUB, noting that the runway was wet due to recent rainfall. While the pilot was aware of the wet surface, they relied on the presence of runway grooving to mitigate hydroplaning risks. The investigation also looked into the runway's friction coefficient; although the last measurement was 16 months old—exceeding the 12-month regulatory interval—the most recent recorded values were within acceptable limits.
Investigators found that the pilot used a performance calculation table from the aircraft's checklist rather than the full Aircraft Flight Manual (AFM). The checklist table only accounted for altitude, weight, and temperature, omitting critical variables such as wind direction, wind intensity, and runway condition. Furthermore, inaccuracies in calculating the operational empty weight and the actual weight of the occupants led to a landing weight that exceeded the manufacturer's maximum limit of 8,000 lbs. Additionally, a conservative fuel load added approximately 300 lbs of extra weight, further impacting the required landing distance.
Findings
- The aircraft was operating above the maximum landing weight limit.
- The required landing distance for the existing conditions (including a 15% margin for wet runways) was approximately 1,062 meters, which exceeded the available runway length.
- The pilot relied on an incomplete performance calculation method from the checklist instead of the AFM.
- A tailwind was present during the landing, contributing to the aircraft "floating" and increasing the ground roll.
- Inadequate operational dispatch planning regarding weight, wind, and runway condition was the primary cause of the excursion.