What happened
During the landing roll-out, the pilot reported that the aircraft's brakes initially appeared functional but began to lose effectiveness halfway through the rollout. The pilot attempted to troubleshoot the issue using the aircraft checklist; however, the loss of braking effectiveness was not an item covered by the available procedures.
After evaluating options, the pilot decided against attempting a landing at a nearby airport with asphalt runways located approximately 8 nautical miles away. Instead, the pilot opted to land in tall weeds situated parallel to runway 09 at 20II. While the vegetation helped slow the aircraft, the pneumatic braking action remained weak and insufficient to stop the plane before it impacted trees at the end of the landing run.
The investigation
A post-accident examination of the aircraft was conducted to identify potential mechanical failures. Investigators found that the brake handle in the front cockpit had not been properly adjusted. This improper adjustment resulted in insufficient travel in the handle, which prevented the brakes from being fully engaged. No other mechanical anomalies associated with a pre-existing condition were identified during the inspection.