After leveling off at 28,000 feet at 15:10 UTC, the aircraft continued in level flight at consistent speed until 15:19 UTC at which point the vertical rate decreases dramatically and the aircraft descends briefly before climbing to a maximum altitude of 30,100 feet before descending back to roughly 27,500 feet. It again climbs, reaching 29,300 feet before leveling off once again. It then descends, with the final data received at 15:20:14 UTC at an altitude of 19,725 feet. The altitude graph below shows the final 32 seconds of received altitude data.