What happened
On 23 September 2005, a Piper PA-28R-180 Cherokee Arrow, registration G-OKAG, was conducting a private flight from Stapleford near London to Llandegla Airfield in Wales. As the aircraft approached its destination, deteriorating weather conditions prompted the pilot to divert to Chirk Airfield.
Upon arrival at Chirk, the pilot performed an overhead join and an orbit to familiarize himself with the airfield layout. The pilot opted to land on Runway 19, which was a 500 m grass runway with an uphill slope. The aircraft completed a go-around before performing a second approach at 75 mph with full flaps. While the touchdown was within the first 60 m of the runway, the application of wheel brakes caused the aircraft to skid on the long, wet grass. Due to the combination of the slippery surface and the uphill gradient, the aircraft could not be stopped within the remaining runway length. The pilot steered the aircraft toward a wire fence to avoid larger obstructions; during the excursion, the propeller and left wing struck a Portacabin, and the right wing subsequently hit a fence post. There were no injuries to the pilot or the passenger.
The investigation
The investigation examined the runway surface and the environmental conditions at the time of the accident. It was noted that the runway consisted of long, wet grass on an ill-defined uphill slope. The investigation also looked into the wind conditions, noting that while the pilot had checked wind information via telephone, local geography can cause significant variations in wind direction at different heights. Post-accident observations at the site revealed discrepancies between the wind direction indicated by a nearby industrial chimney and the airfield windsock.
Findings
- The aircraft was unable to stop on the available runway because the long, wet grass surface significantly increased the required landing distance.
- Calculations suggested that the required landing distance for the aircraft's weight and conditions could have been between 459 m and 544 m, exceeding the 500 m runway length.
- The pilot's decision to divert was appropriate due to the weather, but the runway surface conditions at the alternate airfield were marginal for the aircraft's stopping capability.