A defective sensor on a Lion Air 737 Max which is crucially involved in the deadly crash of the jetliners last October and a traumatic ride in the previous day was reconditioned through a US aircraft maintenance facility before the tragedy, according to the probing documents.
The crash investigators in Indonesia, home of Lion Air, and the US, where the aircraft manufacturer Boeing Co is based, have been probing the work that a Florida mending shop previously implemented on the so-called angle-of-attack sensor, according to briefing documents presented to the parliament of Indonesia.
Misleading signals by the sensors lead to the repeated nose-down movements on the flight of 29th October in which the pilots wrestled with until the jet dived into the Java Sea, killing all 189 people aboard, as per the preliminary report of the deadly crash by the Indonesian investigators.
The crash of Lion Air in Indonesia and another similar one Ethiopian airlines within five months together triggered the rescinding of the best-selling jet of Boeing on 13th March and instigated a global mutiny against the US aviation regulators. The investigators have emphasized the role of the sensors in the two disasters.
The obtained documents by Bloomberg present the repair station XTRA Aerospace Inc in Miramar, Florida, had worked on the sensor. It was later implemented on the Lion Air plane on 28th October in Bali, the problematic report of instruments which displays speed and altitude presented by the pilots. There was no trace about the maintenance service by the Florida shop on the jet device of Ethiopia.
The Indonesian National Transportation Safety Committee is claiming data “ from repair station in Florida” where the unit was working on as per the investigative agency said in an instruction to parliament in the last November and limited in a presentation.
The angle-of-attack sensors, which work like a wind blade on the side of a jet, are architectured for showing how air is streaming relative to where the nose is V-shaped and warn pilots of a two-step climb that could consequence in an aerodynamic stall. In the case of the Lion Air flights, the left-installed sensor was presenting the nose pointed almost 20 degrees higher than the actual measurement.
It was that misleading indication which led an anti-stall computer system to get the assumption about the plane was in danger of losing lift and to repeatedly attempt to push down the nose on the final flight and the one which came before, according to the preliminary report which mentioned information from the crash-proof data recorder of the aircraft.
XTRA Aerospace is certified by the US Federal Aviation Administration for performing repairs on multiple Boeing and Airbus SE models as per the information of the website.