"The accident was due to a series of errors on the part of the pilots who failed to take into account the signals emitted by the plane’s instruments," the source, who spoke on condition of anonymity, told AFP.
"The preliminary findings indicate that until the last moment the plane was perfectly functioning and point to error on the part of the pilot and co-pilot, both of whom had little experience with the jet," the source added.
The pilot erroneously believed that the jet was on automatic pilot and as a result he and his co-pilot failed to heed the alarm signals as the plane veered dangerously off course before crashing, he added.
"Apparently, this is an accident that could have easily been avoided," he said.
The Ethiopian Airlines Boeing 737-800 went down minutes after taking off from
Lebanese officials have previously said that data recovered from the plane’s black box showed all instruments were working well until it plunged into the
They have also ruled out sabotage.
The preliminary report, which has not been made public, indicates that the two pilots’ inexperience with the jet was "certainly behind the accident," the source said.
The pilot had one month experience with the Boeing 737-800 and his co-pilot had four months experience, he added.
"The pilot also had apparently clocked in 200 hours of flight time in one month before the fatal crash, which is way above accepted standards in Europe or the
He said investigators were now focusing on the maintenance of the plane and the two pilots’ background but that the probe was 90 percent completed.
Lebanese Information Minister Tarek Mitri said he could not comment on the preliminary findings before the release of the final report in about three months.
The probe into the crash is being led by the Bureau d’Enquetes et d’Analyses (BEA),
American and Ethiopian investigators are also involved in the probe.
None of the investigators would comment on the preliminary findings.