Incident Overview
On 7 March 2010, at approximately 1500Z, a Piper PA28-180 aircraft registered as ZS-PEV experienced an in-flight failure of its upper engine cowling. The aircraft, operated by 43 Air School (Pty) Ltd, was on a navigation training flight from Beaufort West Aerodrome (FABW) to Upington Aerodrome (FAUP). There were two occupants on board, both student pilots. The aircraft had departed FABW at approximately 1500Z alongside two other training aircraft (ZS-FYS and ZS-MTU).
Sequence of Events
Shortly after takeoff, while climbing to 1500 feet, the upper engine cowling suddenly broke into two halves. The right half struck and broke the windshield, with broken glass entering the cabin. The left half remained attached by a forward left latch but swung into the propeller's plane of rotation, sustaining further damage from the propeller. The pilot reported a gradual loss of engine power following the cowling failure. He initiated a descent and executed an emergency landing in an open field on a farm. During the landing roll, the aircraft struck a farm wire fence. Both occupants evacuated without injuries.
Aircraft and Damage
The aircraft, a 1973 Piper PA28-180 (serial number 28-7305566), had accumulated 7257 total airframe hours. It was powered by a Lycoming O-360-A4A engine and equipped with a Sensenich propeller. The most recent maintenance inspection was performed on 1 March 2010. The aircraft sustained minor damage, including the broken windshield, missing right cowling half, and propeller damage. The missing cowling part was not recovered.
Pre-Flight Inspection
Before departure from FABW, the pilot conducted a pre-flight inspection and noted low engine oil. He attempted to remove the upper cowling to access the oil filler but found it stuck. Instead, he used the oil filler door on the cowling to add oil. The pilot stated that the cowling was properly secured before flight.
Meteorological Conditions
Weather at FABW at the time of departure: surface wind 090° at 5 knots, temperature 32°C, visibility good, cloud and visibility OK (CAVOK), dew point 13°C. The pilot obtained the official forecast from the Cape Town East weather office.
Probable Cause
The investigation determined the probable cause to be the pilot's failure to secure the engine cowling during the pre-flight inspection.
Additional Information
The incident occurred approximately 10 nautical miles from Beaufort West Aerodrome. No injuries were reported. The aircraft's documentation and equipment were found to be valid and serviceable. The two occupants were both student pilots; the passenger held a private pilot licence with 113.4 total flying hours, and the pilot in command had 117.3 total hours, including 52.4 hours on type.