Madrid - An investigating judge has accused two aviation technicians and a maintenance chief of manslaughter in the Madrid air crash that killed 154 people on August 20, judicial sources said Thursday.

Judge Juan Javier Perez will question the three on suspicion of manslaughter on 154 counts and involuntarily causing injuries on 18 counts.

The judge also ordered the creation of a second investigating commission in addition to a civil aviation commission that has released a preliminary report on the accident.

The Spanair MD-82 jet that crashed immediately after take-off did not have its wing flaps and slats deployed, and the plane's warning system failed to inform the pilots of the problem, according to the preliminary report.

The malfunction of the flaps and slats, which help lift aircraft on take-off, may have affected the stability of the plane and caused the crash, judge Perez said in the resolution he issued.

Two Spanair mechanics at Madrid airport disconnected a faulty temperature gauge inside the MD-82 before it took off, but may have failed to realize that the problem could be connected to others in mechanisms including the cockpit warning system, the judge said.

Perez will also question the Spanair maintenance chief at Madrid airport.

The flaps and slats of the plane had already failed to function correctly twice before during the month of August, the judge observed.

Perez began hearing witnesses on Wednesday in a new phase of the investigation after the civil aviation commission released its preliminary report.

Perez ordered the creation of a new commission, because the current one is expected to take a year to issue its final report. The new commission will comprise pilots, mechanics and engineers.

The aviation technicians' association Asetma criticized the resolution, saying the judge was accusing the last links in the chain of responsibility.

Eighteen people survived Spain's worst aviation accident in 25 years. The plane was en route to Las Palmas in the Canary Islands. (dpa)