Unretracted landing gear, engine failure? Veteran pilot analyses AI-171 crash

Captain Rai pointed to a crucial anomaly visible in CCTV footage: the landing gear had not been retracted after take-off. "His rate of rotation and the way he climbed up is very normal. But something has gone wrong towards maybe an altitude of 400 to 500 feet. The aircraft reached about 600 feet, but the undercarriage was still down," he said.

He explained that standard procedure requires the gear to be retracted once the aircraft achieves a positive rate of climb, which happens typically within the first 100 feet after take-off. The failure to do so severely hampers climb performance and raises significant questions.

Possible scenarios

Rai outlined several potential scenarios. One is a bird hit, although that has largely been ruled out. Another possibility is a sudden loss of power, which may have distracted the crew from retracting the gear.

A third, rarer scenario could involve the co-pilot mistakenly retracting the flaps instead of the landing gear. "Retraction of flaps will result in immediate loss of lift. And with the gear down, the thrust will not be able to cope with the drag," he said. He emphasized that only data from the digital flight data recorder (DFDR), or black box, can reveal the actual cause.

Could it be an engine failure?

The veteran pilot also discussed the chance of an engine failure. "One possibility is that one engine failed, and the wrong engine was shut down. Or, in a rare case, both engines failed," he said. However, he noted that recovery would be extremely difficult with such limited altitude and time.

"In such a case, the pilots had about 25 seconds. After accounting for reaction time, they had maybe 20 seconds to recover. That is a very narrow window," he added.

Simulator training prepares pilots, but not for everything

Captain Rai explained the rigorous simulator training pilots undergo. "In the simulator, we face different kinds of emergencies at least twice a year. The simulator is extremely realistic. But dual engine failure training is not commonly done because it's an event with one-in-a-million probability," he said.

He stressed that in simulators, gear retraction after positive climb is among the first actions taught. "Only after that are we presented with emergencies like engine fire or failure. The gear-down issue seems central to this tragedy," he said.

The veteran captain reiterated that while pilots are trained for high-pressure situations, the short time available during this flight likely left no room for recovery. The definitive answers, he said, would only come through a thorough investigation of the flight data.