The AirAsia passenger jet that crashed into the Java sea in December last year killing 162 people was caused by a faulty component and the crew’s subsequent attempts to fix it, Indonesian investigators have said.

Officials probing the accident have focused on the crew’s response to problems with the system controlling the aircraft’s rudder.

They say the soldering on the rudder control system was cracked and the system sent four warning alerts to the pilots, which they responded to by resetting the system in an attempt to fix it.

This action caused the aircraft’s autopilot to disengage, causing the loss of control of the plane, the BBC reports.

“Subsequent flight crew action resulted in inability to control the aircraft … causing the aircraft to depart from the normal flight envelope and enter a prolonged stall condition that was beyond the capability of the flight crew to recover,” the national transport safety committee said in a statement.

In pictures: Missing AirAsia flight QZ8501 Show all 28 1 /28 In pictures: Missing AirAsia flight QZ8501 In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian rescue personnel unload body bags from a military helicopter in Pangkalan Bun containing bodies recovered from the underwater wreckage of ill-fated AirAsia flight QZ8501 In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian rescue personnel unload body bags from a military helicopter in Pangkalan Bun containing bodies recovered from the underwater wreckage of ill-fated AirAsia flight QZ8501 In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian national search and rescue agency's (BASARNAS) members prepare the lifting bags for recovery of the fuselage of crashed AirAsia flight QZ8501 at Panglima Utar Kumai Harbour in Kumai, Central Borneo In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 A member of Indonesia's search and rescue team walks past wreckage of AirAsia flight QZ8501 recovered at sea and stored in a warehouse for investigators in Kumai, Central Kalimantan on Borneo island In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Members of the National Search and Rescue Agency carry coffins containing bodies of the victims aboard AirAsia Flight 8501 to transfer to Surabaya at the airport in Pangkalan Bun In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian search and rescue personnel pull wreckage of AirAsia flight QZ8501 onto the Crest Onyx ship at sea In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 An Indonesian diver and an official examine the wreckage from AirAsia flight QZ8501 after it was lifted into the Crest Onyx ship at sea In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian rescue personnels carry a wrecked seat of the AirAsia Flight QZ8501 airliner recovered from the crash site at Kumai port in Pangkalan Bun, Central Borneo In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 After nearly a week of searching for the victims, rescue teams have so far recovered 30 bodies Getty In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian Air Force personnel during a search operation for the victims of the crashed AirAsia plane over the Java Sea, 1 January 2015 EPA In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian officers carry coffins with the remains of passengers of the AirAsia flight QZ8501 AFP/Getty In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 A coffin of a victim of AirAsia flight QZ8501 is transferred from a local hospital in Pangkalan Bun, the town with the nearest airstrip to the crash site of AirAsia flight QZ8501, in Central Kalimantan In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian national search and rescue agency (BASARNAS) members and Indonesian Air Force crew carry a dead body from a helicopter, during search and rescue operations for the crashed AirAsia plane, at Iskandar Military Airport, in Pangkalan Bun, Central Borneo, Indonesia In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 A vigil for victims of the AirAsia flight QZ8501 crash in Surabaya, Indonesia Getty Images In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Members of the Indonesia marines unload their diving equipment In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Indonesian people pray for passengers of the missing AirAsia flight QZ8501 in Malang, East Java In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Messages for passengers on board the missing AirAsia flight 8501 are placed on a board at Changi International Airport in Singapore In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Commander of Indonesian Air Force 1st Operational Command Rear Marshall Dwi Putranto, center, shows the airplane parts and a suitcase found floating on the water near the site where AirAsia Flight 8501 disappeared, during a press conference at the airbase in Pangkalan Bun, Central Borneo, Indonesia In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Captain Irianto's (the pilot of AirAsia QZ8501 flight) relatives and his wife Widiya Sukati (3rd L) Putri gather in his house at Sidoarjo in Surabaya, Indonesia In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Family members of passengers onboard missing Malaysian air carrier AirAsia flight QZ8501 pray together while waiting for a briefing inside the crisis-centre set up at Juanda International Airport in Surabaya AFP PHOTO / MANAN VATSYAYANAMANAN VATSYAYANA/AFP/Getty Images In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 An Indonesian Navy airman prays on his plane before searching the waters near Bangka Island for debris from AirAsia Flight QZ8501 Ed Wray/Getty Images In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Family members of passengers onboard the missing Malaysian air carrier AirAsia flight QZ8501 react after watching news reports showing an unidentified body floating in the Java sea, inside the crisis-centre set up at Juanda International Airport in Surabaya In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 An unidentified object, found during a search and rescue operation by the Indonesian Air Force for the missing AirAsia plane, is seen floating in the ocean off the coast of Pangkalan Bun, Borneo, Indonesia In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Authorities monitor progress in the search for AirAsia Flight QZ8501 in the Mission Control Center inside the National Search and Rescue Agency in Jakarta Reuters In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Relatives hold a picture of the Herumanto Tanus family as they wait for news from the missing AirAsia plane EPA In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 A relative looks to a list of passengers of Air Asia missing plane at Juanda Airport, Surabaya, Indonesia EPA In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 Relatives cry and comfort each other EPA In pictures: Missing AirAsia flight QZ8501 Missing AirAsia flight QZ8501 A child writes a post-it note on a board of well wishes for the passengers of the missing AirAsia flight QZ 8501, outside the relatives' holding area at Changi airport in Singapore EPA/WALLACE WOON

Aircraft maintenance records show the faulty component had malfunctioned four times during the flight and 23 times in the 12 months prior to the crash.

AirAsia flight QZ8501 disappeared from radar during bad weather on 28 December 2014, less than halfway into a two-hour flight from Surabaya, Indonesia, to Singapore.

The report into the crash, which has been the result of a year-long investigation, said bad weather conditions did not play a role in the tragedy.

Earlier this year it was reported that investigators found the captain of the flight had taken the “very unusual” step of disabling the Flight Augmentation Computer. Shortly after this is thought to have happened, the plane went into a sharp climb that is said to have caused it to stall.

Co-pilot at controls when AirAsia plane crashed

Investigators had previously confirmed co-pilot Remi Plesel, 46, the second-in-command, was in control of the flight when it crashed. The plane is known to have risen sharply upwards to 37,400ft in the space of 30 seconds, before dropping back to 32,000ft in a three-minute stretch.