A pilot of South African Airways has resigned after operating planes for the airline with a fake license for over 20 years.

William Chandler, a former senior pilot at South African Airways (SAA), was found to have flown commercial planes for over 20 years with a forged Airline Transport Pilot License (ATPL).

The discovery was made following a “reportable incident” on a November 2018 flight (SA206) from OR Tambo International Airport in Johannesburg to Frankfurt, Germany.

Chandler was the monitoring pilot for Airbus A340-600, which made erratic maneuvers after encountering turbulence over the Swiss Alps.

According to reports Chandler joined SAA as a flight engineer before becoming a pilot in 1994. He held only a Commercial Pilot License (CPL), which permitted him to operate smaller aircraft but not the long-haul international flights he was assigned to.

The ATPL, which requires 1,500 hours of flight time, including 100 hours at night, along with rigorous technical and medical exams, was fraudulently misrepresented by Chandler.

He allegedly altered documents issued by the South African Civil Aviation Authority (SACAA) to falsely claim possession of the advanced license.

The incident in November 2018 prompted a routine safety investigation, during which Chandler’s credentials were scrutinized, revealing the forgery.