In­done­sian in­ves­ti­ga­tors say doomed Lion Air jet ‘air­wor­thy’ be­fore flight

The Myanmar Times - Weekend - - Asean Focus -

IN­VES­TI­GA­TORS of the Oc­to­ber 29 crash of a Lion Air flight into the Java Sea say the Boe­ing 737 MAX air­craft was deemed air­wor­thy when it made its fi­nal take­off from Jakarta.

The of­fi­cials sum­moned re­porters Thurs­day to clar­ify com­ments made at a news con­fer­ence the day be­fore, where some me­dia re­ported the in­ves­ti­ga­tors had said the plane was not air­wor­thy when it took off.

“The NTSC and the Head of Avi­a­tion Com­mu­ni­ca­tion never stated that Lion Air, Boe­ing 737-8 MAX air­craft reg­is­tered PK-LQP, was not air­wor­thy,” said in­ves­ti­ga­tor Nurc­ahyo Utomo.

The is­sue of air­wor­thi­ness is cru­cial be­cause of con­cerns over tech­ni­cal is­sues with the new Boe­ing 737 MAX that crashed and ques­tions over the air­line’s safety pro­ce­dures.

Black box data showed the pi­lots fought against an au­to­mated sys­tem that pitched a Boe­ing jet­liner’s nose down re­peat­edly be­cause of a faulty sen­sor un­til they fi­nally lost con­trol. All 189 peo­ple aboard the flight from Jakarta to a re­gional air­port died in the dis­as­ter.

The Na­tional Trans­porta­tion Safety Com­mis­sion in­ves­ti­ga­tors were re­port­ing this week on data from the air­craft’s black boxes. The pre­lim­i­nary re­port stopped short of plac­ing blame for the crash – the in­ves­ti­ga­tion is con­tin­u­ing – but it pro­vided new de­tails about the pi­lots’ dif­fi­cul­ties han­dling the highly au­to­mated jet and Lion Air’s in­abil­ity to fix prob­lems with air-speed sen­sors on the plane.

The in­ves­ti­ga­tors say the cock­pit voice recorder, which is still miss­ing and be­ing searched for, is needed to un­der­stand what ex­actly caused the jet to plunge in the Java Sea just 11 min­utes after take­off.

On Wed­nes­day, Utomo said the plane had ex­pe­ri­enced tech­ni­cal prob­lems on four of the six flights be­fore it crashed. On its penul­ti­mate flight from the Ba­li­nese cap­i­tal of Den­pasar to Jakarta, as dur­ing the fi­nal one, pi­lots strug­gled to pre­vent an au­to­matic safety fea­ture from forc­ing the nose of the air­craft down due to prob­lems with its air-speed sen­sors.

The re­port re­leased Wed­nes­day noted that dur­ing the Den­pasar to Jakarta flight a “stick shaker” ac­ti­va­tion – a warn­ing sig­nal to pi­lots that the plane is go­ing too slowly to main­tain lift – con­tin­ued through­out the flight as the flight crew strug­gled and even­tu­ally suc­ceeded to bring the air­craft un­der con­trol.

“This con­di­tion is con­sid­ered as an un-air­wor­thy con­di­tion and the flight shall not be con­tin­ued,” it said of that flight.

Utomo said that based on main­te­nance records, flight engi­neers had made re­pairs and run tests as needed. “Based on the test re­sults, the air­craft was de­clared air­wor­thy, also when the plane de­parted from Jakarta, the air­craft was in air­wor­thy con­di­tion,” he said.

An­other in­ves­ti­ga­tor, Ony Suryo Wi­bowo, said there were spe­cial pro­ce­dures to be fol­lowed when there are prob­lems with an air­craft.

“But in prin­ci­ple, when the en­gi­neer has stated it’s air­wor­thy, then it’s air­wor­thy,” he said.

Wi­bowo said the pi­lot would make the fi­nal de­ci­sion about whether to can­cel or abort a flight, and the in­ves­ti­ga­tors were try­ing to un­der­stand how the pi­lot made his de­ci­sion.

“When the plane is on the ground, the re­spon­si­bil­ity for air­wor­thi­ness is on the en­gi­neer, and when the plane is in the air, the air­wor­thi­ness is en­tirely in the pi­lot’s hands,” he said.

Ex­perts say Boe­ing may need to change its new anti-stall sys­tem, per­haps de­vel­op­ing an al­go­rithm to dis­re­gard sen­sor read­ings that ap­pear off-base.

Photo: AP

A worker in­spects parts of Lion Air Flight 610 re­trieved from the site of the plane crash, at Tan­jung Priok Port in Jakarta, In­done­sia, on Oc­to­ber 31.

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