Aircraft Was Skirting Weather, CVR Recording 'Unusable'

The French aviation accident investigation organization BEA says that the Swiftair MD-83 which went down in Mali last month entered a spiraling descent from which it did not recover.

According to the report, the airplane's flight path as it was reconstituted from the FDR data, superimposed over a satellite image of the cloud mass present on the day of the accident (pictured), shows a normal climb and start of cruise, with some moderate route changes that are typical of a strategy to avoid any developing weather.

The aircraft took off from Ouagadougou at 1h151. It climbed and reached flight level 310 at 1h37, and at flight level 310, the airplane stabilized in cruise at a speed of about 280 kt. Around two minutes after the start of cruise, while remaining at flight level 310, the speed dropped progressively, and the airplane began descending progressively and the speed continued to drop down to about 160 kt.

The airplane then turned left and quickly lost altitude, with large changes in pitch and bank. The rotation to the left continued until the end of the recording. The last recorded point, 1h47mn15s, corresponds to an altitude of 1,600ft, a speed of about 380 kt and an extremely high descent speed.

The BEA says that the tape in the badly-damaged Cockpit Voice recorder was repaired, but the information on the tape is unusable due apparently to a recorder malfunction unrelated to the damage that resulted from the accident. "Analysis continues to try to find a means of extracting some information, but is it not possible to predict the outcome of this approach," the report says.

The absence of usable data from the CVR at present underlines the need to collect all data on communications that the crew may have made with organizations on the ground or with other aircraft.

(Images provided by BEA)

FMI: www.bea.aero/en/enquetes/flight.ah.5017/flight.ah.5017.php#utc