The PIA Convair CV-240 aircraft had landed at Delhi-Palam at 19:02 hours following an uneventful flight from Karachi. It was prepared for the return flight and taxied to runway 27 for departure. It was a moonless night and the visibility was almost 3 km due to dust haze. Takeoff was away from the built up area so there were no visual reference points and there was nothing which could have given the pilot a natural horizon. Takeoff was commenced at 20:18. Shortly after becoming airborne the landing gear was raised. Then the airplane began to descend again. It struck the ground at a shallow nose-down angle with the port wing slightly low and caught fire. PROBABLE CAUSE: “The captain did not properly observe and interpret his flight instruments and thus inadvertently permitted the aircraft to descend to the ground immediately after a night takeoff during which no visual reference was possible. A contributory factor may have been the slow reactions of the captain due to his state of health.”