cabin floor had vents like these, only the rear section of the aircraft lacked them. Additionally, the NTSB recommended that upgrades to the locking mechanism and to the latching actuator electrical system be made compulsory. Despite this, the Federal Aviation Administration (FAA) did not issue an Airworthiness Directive requiring these changes, instead reaching a gentlemen's agreement with McDonnell-Douglas to make some lesser changes to the hatch and no changes to the floor. The Flight 981 aircraft, registration TC-JAV (also known as "Ship 29"), had been ordered from McDonnell-Douglas three months after the service bulletin was issued, and was delivered to Turkish Airlines three months later. Despite this, the changes required by the service bulletin (installation of a support plate for the handle linkage, preventing the bending of the linkage seen in the Flight 96 incident) had not been implemented. Through either oversight or deliberate fraud, the manufacturer construction logs showed that this work had been carried out. In addition, an improper adjustment had later been made to the locking pin mechanism on the Flight 981 aircraft, causing the locking pin travel to be reduced. This meant that the pins did not extend past the torque tube flanges, allowing the handle to be closed without excessive force (estimated by investigators to be around ) despite the improperly engaged latches. These findings concurred with statements made by Mohammed Mahmoudi, the baggage handler who had closed the door on Flight 981; he noted that no particular amount of force was needed to close the locking handle. Changes had also been made to the warning light switch mechanism, the unintended consequence of which was that the cockpit warning light would be extinguished even though the latches were not fully in place. After Flight 96, McDonnell-Douglas added a small peephole that allows baggage handlers to visually inspect the pins to confirm they were in the correct position, and information placards to show the correct and incorrect positions of the pins. This modification had been applied to Flight 981's plane; however, Mahmoudi had not been instructed about the purpose of the indicator window; he had been told that as long as the door latch handle stowed correctly and the vent flap closed at the same time, the door was safely latched. Furthermore, the instructions on the plane regarding the indicator window were printed in English and Turkish, but Algerian-born Mahmoudi, who was fluent in three other