What happened
On 11 December 2005, a Lindstrand 105A hot air balloon, registration G-RIMB, was conducting a passenger flight near Darwen, Lancashire. After a period of stable flight, the commander attempted to land on a slope near the crest of a hill. During the descent, the balloon encountered unexpectedly strong winds that caused the aircraft to collide with power cables and telegraph lines.
The impact with the cables caused the basket to be dragged along the lines, leading to the breakage of one set of flying wires due to chafing. This resulted in the basket dropping approximately 12 feet onto a road. The momentum of the envelope then dragged the basket across the road until it came to rest against a stone wall. During the sequence, the envelope draped over trees and a house roof, and the burner structure sustained damage from electrical arcing.
The investigation
The AAIB examined the flight path using data from a handheld GPS unit carried in the basket. The investigation also reviewed meteorological reports from the Met Office and the pilot's pre-flight weather assessment. Investigators analyzed the local topography, noting that the landscape of hills and valleys near Darwen Moor can significantly influence wind behavior through topographical forcing.
Findings
- The primary cause of the accident was the encounter with unexpectedly strong winds at the crest of the hill during the landing approach.
- Local terrain features likely caused the wind to accelerate as it approached the hill crest.
- The collision with the power cables led to the breakage of flying wires and subsequent damage to the burner and basket structure.
- One passenger sustained injuries requiring stitches, while the crew and other passengers were treated for minor bruising.
Safety action
No specific safety recommendations were recorded in this report.