Zitat

Das verschollene Flugzeug der Air Algerie ist nach UN-Angaben über Mali
abgestürzt. Wie ein Kommandeur der dortigen UN-Mission, Brigadegeneral
Koko Essien, am Donnerstag der Nachrichtenagentur dpa sagte,
verunglückte die Maschine im Zentrum des Landes zwischen den Städten Gao
und Tessalit.

Zitat

An Bord des Fluges von Burkina Faso nach Algerien seien neben den 110
Passagieren auch sechs Besatzungsmitglieder gewesen.
Rettungsmannschaften und die Fluggesellschaft arbeiteten daran, die
Umstände des Verschwindens zu klären, teilte Swiftair mit.

Zitat

ALGIER - Der malische Präsident Ibrahim Boubacar Keita hat bestätigt, dass das Wrack der in Mali abgestürzten McDonnell Douglas MD-83 entdeckt worden sei. Im Präsidentenpalast in Bamako sagte er am Donnerstagabend vor Journalisten, das verunglückte Flugzeug sei zwischen Kidal and Tessalit weit im Norden des Landes entdeckt worden.

Zitat

Schon vor dem Absturz von Flug AH5017 beklagten sich die Angestellten über Swiftair. Sie monieren «physische und psychische Müdigkeit» - vor allem auf der Air-Algérie-Strecke.

Zitat

A first trajectory of the aircraft based on flight data recorder has been established. The trajectory shows a normal departure from Ouagadougou, the aircraft reached cruise FL310 at 01:37Z about 22 minutes after departure, the aircraft's indicated airspeed was 280 KIAS at the time. About two minutes later the speed decreased gradually, the aircraft began to descend gradually, the speed continued to decrease to 160 KIAS. The aircraft subsequently began a left turn and descended rapidly with changes in pitch and angle of attack. The last position recorded by the flight data recorder at 01:47:15Z was at 1600 feet MSL, about 380 KIAS and a very high rate of descent.

Zitat von »mike november«

Vereisung in FL310? Ist da noch genug Feuchte vorhanden?

Zitat

The flight data recorder revealed that EPR and N1 fluctuations occurred on both engines for about 45 seconds, then over the next 25 seconds the EPR increased from 1.6 to 2.5 and decreased again twice, N1 varied between 70 and 91 percent, roll oscillations 4 degrees to the left and right occurred, autothrottle disengaged between the EPR oscillations 1.6 and 2.5.

About 65 seconds after the EPR/N1 oscillations began the airspeed had decayed to 203 KIAS/0.561 mach and the aircraft began to descend, 29 seconds later the autopilot disengaged, at that time the aircraft had lost 1150 feet of altitude, airspeed was 162 KIAS, 0.439 mach and both engines were nearly at idle.

Zitat

On Apr 2nd 2015 the French BEA released further preliminary information based on computations and assessments by the engine manufacturer.

The BEA reported that about 2 minutes after the aircraft levelled off at FL310 the EPR indications of the right hand engine became erroneous, another 55 seconds later the EPR indications of the left hand engine also became erroneous. These erroneous EPR indications are likely the result of pressure sensors located at the engine inlet having iced up.

Analysis of the data suggests that the related anti ice systems had not been activated during climb and cruise.

As result of the blocked pressure sensors and resulting incorrect EPR data autothrottle limited the thrust available at an value that was insufficient to maintain speed. Over 5:35 minutes the aircraft's indicated speed reduced from 290 to 200 knots, the angle of attack increased beyond stall. 20 seconds after the aircraft entered stall the autopilot disconnected causing the aircraft to abruptedly roll left to a bank angle of 140 degrees and a drop of the nose by about 80 degrees. The recorded data suggest that there has been no stall recovery done by the crew. Following the roll and nose down there are control inputs recorded to roll the aircraft right and pull the nose up.

The BEA reported that there had been 2 similiar occurrences before: On Jun 4th 2002 a Spirit Airlines MD-82 registration N823NK was in flight at FL330 in daylight out of clouds when power was lost in both engines due to overestimated EPR values due to ice crystals blocking both pressure sensors at the engine inlet, the crew descended the aircraft, activated the anti-ice systems and continued to destination, and on Jun 8th 2014 a Swiftair MD-83 registration EC-JUG was in level flight at FL330 in daylight above cloud layer, when the crew noticed the problem, engaged the anti-ice clearing the problem before reaching stall and continued to destination.

The investigation continues, the final report is estimated for December 2015.

Zitat von »Flugzeugschrauber«

Meine anfängliche Vermutung scheint sich immer mehr zu bestätigen.