Pilots of Pune-bound flight AI-849, which was ready for take-off with 122 people on board, found during routine checks that the flight management and guidance systems were faulty and the auto-pilot was non-functional, airport sources said.

The pilots, Commander Captain Jalaj Vats and co-pilot Captain Amit Tyagi, refused to fly the faulty Airbus A-320 plane and informed the airline officials, who asked them to change the aircraft.

After a delay of about two-and-a-half hours, they got a similar aircraft that had just returned from a major check. When they took off for Pune, the aircraft's landing gear got jammed while being retracted. Fault also occurred in the plane's auto-pilot and auto-thrust system which controls the power of the engines and the flight director, they said.

Sensing the situation, the pilots decided to return to Delhi and sought permission for priority landing from the air traffic control and landed safely. Taking strong exception to such incidents, major pilot's body -- Indian Commercial Pilots Association (ICPA) -- shot off a letter to Air India management quoting reports relating to flight safety.

"ICPA takes a pledge to provide a safe environment for the safety and security of the innocent flying passengers by operating aircraft which are completely snag-free," ICPA President Captain A S Bhinder said in the letter.