A French court found Airbus and Air France liable on Tuesday for damages over a 1992 plane crash that killed 87 people near the eastern city of Strasbourg but cleared six people of criminal responsibility, according to Reuters. The court ordered the companies to pay compensation to the relatives of those killed. The amount of damages, however, had yet to be determined, and Air France has already paid millions of euros in compensation. A long investigation failed to single out one particular reason why the Air Inter Airbus A320 smashed into a mountain as it approached Strasbourg airport on Jan. 20, 1992. Only nine people survived the crash. "It is a great day, with a small regret," Alvaro Rendon, the head of Echo, a group representing the victims' families, told reporters, referring to the six defendants being cleared of criminal charges. "But Airbus and Air France were found guilty, which for us is the greatest victory," he added. Air Inter was the domestic subsidiary of French flag carrier Air France and has since been absorbed into the parent airline, which has also recently merged with Dutch carrier KLM. The six defendants in the criminal case -- a former air traffic controller, four former managers from the civil aviation authority (DGAC), Air Inter and Airbus Industries, and a former Air Inter deputy director general -- pleaded not guilty to manslaughter. They were accused of committing errors that might have affected the safety of the Airbus A320. The investigation suggested a range of possible factors which might, together, explain what caused the crash. These included the quality of guidance the plane was given to direct it towards Strasbourg airport and the composition of the crew. DAMAGES ALREADY PAID The court found no definite causal link between the crash and the failings four former Air Inter and DGAC employees were accused of, such as not ensuring planes were installed with an alarm system that would have warned the pilots they were close to the ground, which has since become an international norm. It did, however, find air traffic controller Eric Lammari had committed "errors" and Airbus technical director Bernard Ziegler had been negligent. The judges also found that one button in the cockpit controlled two descent speeds, which could have led the pilots to make the plane descend four times too quickly. That cockpit feature has since been changed. As Air France has already paid a total of about 21 million euros ($27 million) to most of the victims' families, the ruling's financial effect on the airline should be limited. It could, however, demand Airbus pay its share of those damages. The narrow-body, 150-seat A320 was the first commercially successful passenger jet built by Airbus, which was set up as a European competitor to U.S. giants such as Boeing. Airbus is now a unit of European aerospace group EADS.