Fat lot of good it did them. Flight data shows the sensor, called the “angle of attack” vane, which measures whether air is flowing parallel to the length of the fuselage or at an angle, was providing inaccurate readings after that. However, the pilots on the harrowing Oct. 28 flight from Bali to Jakarta didn’t mention key issues with the flight after they landed, according to the report. Their request for maintenance didn’t mention they had been getting a stall warning since about 400 feet after takeoff as a result of the faulty angle-of-attack sensor. It was still giving false readings the next morning on the flight that crashed, according to flight data.The report also said that the plane was considered airworthy before takeoff and that the pilots were fully certified to fly the plane.
Airline mechanics tried four times to fix related issues on the plane starting Oct. 26, according to the Indonesia preliminary report. After pilots reported issues with incorrect display of speeds and altitude in the two prior flights, workers in Denspasar, Bali, replaced a key sensor that is used by the Boeing plane to drive down its nose if it senses an emergency.
"The plane's speed exceeded its design limits, Reuters reported, adding that passengers would have experienced negative G-forces before impact. " A typical person can handle about 5 g0 (49 m/s2) (meaning some people might pass out when riding a higher-g roller coaster, which in some cases exceeds this point) before losing consciousness, but through the combination of special g-suits and efforts to strain muscles—both of which act to force blood back into the brain—modern pilots can typically handle a sustained 9 g0 (88 m/s2). In aircraft particularly, vertical g-forces are often positive (force blood towards the feet and away from the head); this causes problems with the eyes and brain in particular. There are isolated incidents of humans surviving abnormally high G-forces, most notably the Air Force officer John Stapp, who demonstrated a human can withstand 46.2 G’s. The experiment only went on a few seconds, but for an instant, his body had weighed over 7,700 pounds.