Pilots didn’t protect cockpit voice recorder data: Probe

MUMBAI: Investigations into a Jet Airways tail strike and hard landing that took place in Dhaka this year have revealed that the pilots involved did not protect the cockpit voice recorder data. The investigation was carried out without this crucial evidence. In its report, the Aircraft Accident Investigation Bureau iterated the responsibility of engineering and maintenance personnel to preserve such crucial data.
A Jet Airways Boeing 737-800 with 160 passengers and eight crew had taken off from Mumbai at 9.15am on January 22 and did an eventful landing in Dhaka around noon, local time.The weather, visibility and wind speed/direction were fine for a normal touchdown, the report said.
The co-pilot was at the controls, with the commander monitoring. The Boeing 737 was overhead the runway for the landing flare phase, the few seconds when the descent rate is cut and the aircraft floats almost parallel to the runway before it is eased into a touchdown. For a smooth touchdown, the Jet training manual instructs pilots to retard the thrust lever to idle. But the copilot forgot to do that, the commander failed to pick up that omission and the aircraft did a hard landing.
The report said that on initial touchdown the aircraft bounced with its nose turned up at an angle higher than normal. “Thereafter, the commander took over controls and the aircraft touched down in second attempt,’’ it said. “During the post-flight walk around inspection at Dhaka, rubbing marks were observed on the tail skid and underbelly of the aircraft,’’ the report said, adding that the aircraft had internal damage too.
What hampered investigations was the fact that post landing, the pilots did not follow standard operating procedures which require that the circuit breaker of the cockpit voice recorder (CVR) be pulled out so that it stops recording. As a result, crucial evidence the pilot’s cockpit conversation was overwritten by other conversations that took place on ground.
But air safety experts brought up another issue. “Any time an aircraft is damaged and the damage affects performance characteristics of an aircraft, it should be considered an accident as per International Civil Aviation Organization norms,’’ said Capt Mohan Ranganthan, an air safety expert. But this was classified as a “serious incident’’.
He added, “This is how Indian aviation authorities cover up, to portray that India has nil accidents.’’