A loss of engine power is emerging as the most likely cause of the crash of the Air India Boeing that killed at least 279 people at Ahmedabad on Thursday.

The Boeing 787-8 series appeared to have suffered from lower than normal thrust from its General Electric GEnx engines as it took off and failed to climb more than 450ft before crashing, video and reports from the Indian authorities have indicated.

The new information has eclipsed an early focus on the unusual configuration of the aircraft’s wing flaps and landing gear.

No cause has yet been identified for what would be an extremely rare power loss from both engines, but on Sunday the Indian civil air authority (DGCA) began urgent pre-flight inspections of fuel systems, electronic engine controls and other systems on Indian Boeing 787s.

Juan Browne, an American airlines Boeing pilot who runs a well-regarded aviation YouTube channel, said: “There was something terribly wrong with this 787 jet and we need to find out really quickly what went wrong because we’ve got a thousand of these operating today and operators need to find out what happened.” The Indian authorities confirmed on Sunday that the 787, the high-tech flagship of the Boeing fleet, struggled to become airborne, using almost all of the 3,500m runway. That is notably more than the length that would have been calculated by the plane’s computer for the hot conditions and heavy load that day. Video of the take-off showed dust thrown up after the end of the runway, indicating power from both engines as the plane passed over. In his emergency call seconds after take-off, the co-pilot told air traffic controllers: “Thrust not achieved … falling … Mayday! Mayday! Mayday!”, according to local aviation sources. Further evidence of a power problem came from another video of the brief flight. This confirmed that the aircraft’s “ram air turbine” (RAT) had been deployed.The RAT, consisting of two propeller-like blades, drops on an arm from under the rear of the fuselage to generate enough electricity to power essential electric and hydraulic systems. This occurs automatically if the aircraft loses electrical and hydraulic power, which normally comes from three independent systems. Videos captured the plane struggling to climb before crashingJAM PRESS/RARE SHOT NEWSThe distinctive “burring” noise, similar to a propeller plane, from the high-speed blades driven by the oncoming air, is clear in the video.Testimony from Vishwash Kumar Ramesh, the sole surviving passenger, also indicated an electrical power failure. The cabin lights flickered and he heard a bang, he said. The noise could have come from an engine “flame-out” or from the RAT deploying, pilots said. Ramesh also said the engines appeared to be revving up when the plane hit the ground, suggesting that some power was still available.Steve Scheibner, an American Airlines Boeing 777 captain, said the new evidence showed the Indian Boeing had suffered a double power loss rather than a loss of lift caused by other factors, as first suspected.“I’m solidly in the camp that there was dual engine failure. The RAT is deployed. you can hear it,” he said. The turbine is not intended to provide enough power and controls for an aircraft to climb after take-off, merely to give minimum control for an emergency descent from altitude, he added.A power loss would explain why the Boeing’s undercarriage remained extended after take-off because the emergency turbine is not designed to provide power to retract it. The cause of the apparent power failure will emerge from analysis of the flight recorders and study of the wreckage. This could range from fuel contamination to failure in the engines’ electronic control systems. The Indian authorities indicated that a bird strike has been ruled out. “We have no idea why both engines on a 787 would flame out right after take off,” Scheibner said.