What happened
On 23 May 2025, a Piper PA-34-200T aircraft with registration AP-BOG, operated by M/s Sky Wings, experienced a failure of its No. 1 engine while taxiing at Jinnah International Airport (JIAP) in Karachi. The aircraft was conducting a training flight involving circuits and Instrument Landing System approaches. After receiving clearance for the approach from Air Traffic Control, the pilot requested to return to the Hamilton hangar. During the subsequent maneuvering on Taxiway "F", the pilot reported an inability to complete a 180-degree turn due to the engine failure and requested ground assistance. The aircraft was eventually towed back to the General Aviation hangar. No injuries were reported among the three crew members, and there was no damage to the aircraft or other property.
The investigation
The Bureau of Aircraft Safety Investigation Pakistan (BASIP) examined the operational history, maintenance records, and organizational factors surrounding the incident. Investigators found that the trainee pilot had not completed required ground training or simulator sessions prior to this first dual-engine circuit training flight. Furthermore, the trainee pilot refused post-incident medical and toxicology testing, violating regulatory requirements, while the captain reported for medical examination five hours after the event. The investigation also uncovered significant organizational deficiencies at Sky Wings, including fraudulent aeromedical documentation facilitated by company officials and a lack of proper maintenance tooling.
Findings
The primary cause of the engine shutdown was identified as an extended period of propeller feathering during pre-take-off checks, which removed aerodynamic load and led to flame-out. This procedural error was exacerbated by the aircraft's spark plugs, which had degraded with carbon deposits, corrosion, oil fouling, and excessive gaps, preventing a successful restart. Contributing factors included an inadequate checklist that lacked time limits for feathering checks, reliance on auditory cues rather than RPM monitoring, and unsafe airport security procedures requiring engine shutdowns without fire cover. Regulatory oversight failed to detect critical maintenance and training deficiencies at the operator.
Safety action
BASIP issued several safety recommendations. Sky Wings was directed to revise pre-take-off checklists to include maximum feathering durations, ensure proper spark plug inspection tools are available, and implement strict compliance with medical examination protocols. The Airport Security Force was advised to review procedures to eliminate mandatory engine shutdowns without fire protection. The Pakistan Civil Aviation Authority (PCAA) was recommended to strengthen oversight of general aviation operators, standardize checklist guidance for Piper aircraft, and enforce regulations regarding maintenance tooling and training records.