What happened
On July 18, 2010, a Cameron Z-210 hot air balloon, registration PH-TYN, was participating in the Eindhoven Ballooning festival. After a flight of approximately 70 minutes, the pilot was forced to perform a landing within a city park in Eindhoven due to unpredictable wind conditions. During the descent, the basket struck the ground upright at high speed, bounced back into the air, and subsequently struck the ground a second time. The impact resulted in two ankle fractures and one bruised ankle among the ten passengers on board.
The investigation
The investigation examined the meteorological conditions, the pilot's flight management, and the landing sequence. The pilot had relied on a KNMI weather forecast and a festival briefing which suggested favorable winds at higher altitudes that would carry the balloon away from the city. However, upon takeoff from Karpendonkse Plas, the wind was found to be blowing toward the city. The pilot attempted to climb to 2,000 and 2,500 feet to find more stable air, but found no significant wind at those levels.
Investigators also looked into the landing mechanics. To prevent the balloon from rising again after touchdown, the pilot released hot air via the parachute and utilized a handling line. Bystanders on the ground assisted by pulling the handling line. The investigation also reviewed the passenger briefing, noting that one passenger had misinterpreted instructions regarding body positioning during landing.
Findings
- The primary cause of the forced landing in the park was unpredictable wind patterns, likely influenced by 'city thermals'—local air circulation caused by the heat of the urban environment.
- The severity of the impact was caused by the simultaneous release of hot air and the pulling of the handling line by bystanders, which caused the basket to hit the ground at high speed.
- One passenger sustained a fracture because they interpreted the instruction to "bend at the knees" as a command to crouch or sit, rather than maintaining a stable stance.
- The pilot's workload was significantly increased by the need to manage passengers, monitor the balloon, and coordinate with ground personnel simultaneously.
Safety action
- It is important to ensure that all passengers fully understand landing instructions, potentially using companions to verify comprehension.
- Caution is required when using ground crews to pull handling lines, as the coordination of these forces can impact the descent rate.