International investigators began their examination Friday of the black boxes from the two aircraft involved in a mid-air collision over southern Germany earlier this week, killing all 71 people on board, including 52 Russian schoolchildren. The results aren't expected until next week, but new problems have emerged with Swiss air traffic control.
It was Swiss air traffic control that was in charge of the airspace over Southern Germany late Monday as the Russian Tupolev-54 with its payload of children approached the flightpath of the cargo plane en route from Bahrein to Brussels.
And the single air traffic controller on duty at the time was laboring under even greater handicaps than previously reported.
It's already been admitted that an automatic reporting system was shut down for routine maintenance at the time.
On Friday, the German federal air accident agency (BFU), said the main telephone system was also down for part of the time.
As a result, the officer on duty was watching five planes on two screens and guiding the approach of one aircraft as it came into land at nearby Friedrichshafen, and was having problems communicating with the German airport on the back-up system.
The German authority also said Friday that the Russian plane received its first warning to take evasive action just 44 seconds before the crash.
Until now, the Swiss have been saying 50 seconds. It might not seem much of a difference, but every second would have counted.
The BFU pointed out that the warning should have been issued a minimum of 90 seconds before the crash.
Meanwhile experts began investigating the flight data and cockpit voice recorders from the two planes in the hope of piecing together additional details of what really happened in those fatal seconds before the two planes headed straight into each other's paths.
Some of the tapes are badly damaged. That's slowed down the investigation and the details are not expected for several days.
And on the ground, search teams began to wind down their operations late Friday. With almost all the bodies now found and the first victims beginning to be identified, a state government official said it was questionable if the last remains would ever be uncovered.