Indonesia's National Transportation Safety Committee says an angle-of-attack sensor on the ill-fated Lion Air Boeing 737 Max 8 had been replaced a day before it crashed.
The committee says the sensor was replaced in Denpasar on 28 October, after pilots reported issues with the airspeed indicator.
Downloaded information from the recovered flight data recorder found that there was a "different [reading] on the angle-of-attack indicator" during a Denpasar-Jakarta flight on 28 October.
It adds that this was related to the faulty airspeed indication, which was first raised at a 5 November press conference by NTSC chief Soerjanto Tjahjono.
After the replacement, however, pilots that flew a Denpasar-Jakarta flight still found a 20° difference on the left-hand angle-of-attack sensor. During this flight, the pilots implemented "a number of procedures" to rectify the issues, and the jet subsequently landed in Jakarta safely.
The sensor that was removed in Denpasar has since been sent to NTSC offices in Jakarta, before being transferred to Boeing's headquarters in Chicago for further investigation. Investigators plan to reconstruct the flight and study the faults related to the sensor using Boeing's engineering simulator in Seattle.
Interviews have also been conducted with the pilots and cabin crews that operated PK-LQP prior to the crash, as well as technicians that maintained the jet in Denpasar, Jakarta, and Manado.
The NTSC adds that, based on issues faced by pilots on the Denpasar-Jakarta flight, it has recommended that Boeing notify 737 Max operators of the potential issues they could face with the sensors.
NTSC investigators and officials from Boeing and General Electric have identified some of the wreckage recovered from the seabed. These include the left CFM International Leap-1B engine, the right-hand main landing-gear, a tail section, aircraft sections 43, 44, 46 and 48, a cockpit oxygen bottle, a left-hand passenger door, and a wing-tip.

Boeing issued a operations manual bulletin on 6 November, directing operators to “existing flight crew procedures" to address circumstances involving erroneous angle-of-attack sensor information.
Indonesia's national search and rescue agency Basarnas has extended its mission to 10 November.

The Lion Air Max 8 was operating as flight JT610 from Jakarta's Soekarno-Hatta International airport to Pangkal Pinang when it crashed into the sea near the town of Karawang, claiming the lives of all 189 passengers and crew on board.

While most commentators agree that long-haul low-cost operators have had a disruptive influence in their respective markets, doubt creeps in when discussion turns to the model's economic viability.
Analysis of some of the key players indicates that those doubts are well founded. Few if any airlines have made true long-haul low-cost work in a sustainable manner, despite some achieving sporadic profitability.
The market's major participants operate mixed networks. In other words, no significant players have become dedicated low-cost long-haul operators.
Long-haul point-to-point services frequently fail to attract enough demand, hampered by the lack of connecting passengers, while having no true business-class products and passengers can fatally stymie revenue opportunities.
When new players do gain some traction, powerful network carriers have been quick with defensive moves.
These and other factors are causing some carriers to rethink their strategies entirely, often leading to the adoption of products more commonly associated with traditional network carriers.
The network carriers themselves are also embracing long-haul low-cost – but it is doubtful whether those units can be considered true budget airlines.
However, the sector remains in its infancy. Many of the markets developed under the long-haul low-cost banner may prove sustainable; but the operating model seems likely to be "lower cost", rather than true low-cost.
Ironically for a market so suited to pioneers, the odds seem stacked against entrepreneurial start-ups.
"Sadly, low-cost long-haul is the graveyard of ambition for start-ups," Ryanair chief operating officer Peter Bellew opined on Twitter after news broke of Primera Air's demise. "[It] seems almost impossible without business class or the deep pockets of a legacy carrier."
As fuel prices rise, the market is only likely to become more unforgiving.

Capacity between China and the USA is beginning to rationalise after years of accelerated growth.
Air China, American Airlines, Hawaiian Airlines, Sichuan Airlines and United Airlines will or have pulled out of markets, while others, including Hainan Airlines, are reducing capacity on existing routes through the end of 2018.
"The two China routes… have been colossal loss makers for us," said Vasu Raja, vice-president of network and schedule planning at American, earlier in August on the carrier's decision to suspend service between Chicago O'Hare and both Beijing and Shanghai Pudong in October.
The Oneworld Alliance carrier opted to suspend the routes in favour of "focusing" – or rationalising, to put it another way – its Asia operation around its Dallas/Fort Worth and Los Angeles hubs, he says.
Rapid industry capacity growth between China and the USA, especially from Beijing and Shanghai, has put pressure on the market for the past few years.
At least as long ago as January 2016, then-American president Scott Kirby – he is president of United Airlines today – spoke of "weakness" to China due to competitive capacity growth. Despite this, the Fort Worth–based carrier continued to grow in the market adding new service between Los Angeles and Beijing in November 2017.
While data does not yet include all of American and Hawaiian's cuts, China-USA capacity will grow 6.7% this year. This is nearly 2.5 percentage points slower than in 2017 and the slowest growth in at least five years.