Biman’s 7 Domestic Flights Last Year: Pilots’ blunder, cover-up put 500 lives at risk

"The Biman management made the decision that the two pilots will not be able to avail any promotion until the departmental action against them is resolved."

— Shafiul Azim, Biman Managing Director and CEO

Did you take any of these seven Biman flights on February 1 and February 2 last year?

BG602 from Sylhet to Dhaka, BG605 and BG606 from Dhaka to Sylhet and back to Dhaka, BG467 and BG468 from Dhaka to Jashore and back to Dhaka, and BG471 and BG472 from Dhaka to Barishal and back to Dhaka.

If so, two Biman pilots knowingly put your life and the lives of around 500 others at risk by hiding the fact that the plane's engines had been damaged due to the captain's improper operations of the plane mid-flight.

According to a Biman investigation, there could have been a catastrophic "inflight engine failure" during any of the seven flights of the De Havilland Canada Dash 8, popularly known as the Dash-8, a 'turboprop short-haul' plane that can carry up to 74 passengers.

The civil aviation law says that the punishment for flying an aircraft in a dangerous manner is life imprisonment. But instead of punishing them, the authorities promoted one of the two pilots for flying long-haul planes.

The promotion was, however, rescinded a day after this paper called the carrier and enquired about the probes into the incident and the pilots in question.

The pilots deliberately concealed the information about damaging the engines.

After overstressing the engines during a flight, it was mandatory for them to file an air-safety report. This would have ensured the immediate grounding of the aircraft, inspections of the engines, and if needed, replacement of the engines altogether.

Filing the report is a Biman flight safety protocol. The pilots did not do that.

They allegedly erased the "maintenance message and fault code message" that should have automatically popped up in the plane's instrument panel. This is according to multiple investigation reports prepared for the government by several agencies, including Biman.

Everything the pilots tried to hide, however, came out because the Dash-8's engines automatically reported to its maker Pratt & Whitney that they had been damaged and let the cat out of the bag.

Biman conducted an investigation but the findings of the investigation report, submitted in March 2022, never saw the light of day.

Biman also had to pay Tk 16.5 crore to fix the plane which was just a year old. This incident also jacked up insurance premiums for all aircraft in Biman's fleet.

When The Daily Star asked about why he did this, the pilot who was in command refused to comment.

THE MISTAKES, COVER-UP

The damage was done during the 2:20pm flight BG601 from Dhaka to Sylhet on February 1, 2022. The plane had 71 passengers.

The pilot in command was 42-year-old Capt Ali Rubyat Chowdhury and his first officer was 27-year-old Rafi Uz Zaman. At the time of the flight, Ali Rubyat had eight times more flying hours under his belt than Zaman.

The investigation report states that the plane took off at 2:33pm and at 2,000 feet altitude, the pilot set the airspeed to 165 knots (nautical miles per hour), which was 20 knots less than the standard operating procedure for the plane.

"As per approved Dash-8 Q400 standard operating procedure, normal climb speed is 185 knots," said Biman's investigation report.

While climbing the next 9,790 feet, the pilot changed the airspeed thrice in four minutes, before finally setting it to 170 knots.

"The captain said that they wanted to climb faster to avoid cumulonimbus [thunderclouds] clouds. This technique to climb out of the weather is not supported by the standard operating procedure," said the report. The meteorological report for the day said that there was "no significant cloud".

The pilot said that they hit turbulence at 12,000 feet just a few seconds after he set 170 knots airspeed.

He said that 12 seconds into the turbulence, the "ice detected" light flashed, meaning ice had started forming on the wings.

However, his statement was not supported by the flight data recorder, which is popularly known as a black box and is an electronic recording device that all commercial planes have to facilitate incident investigations.

As the aircraft's speed was 15 knots below the standard minimum of 185, to begin with, the icing conditions supposedly sent the plane's speed plummeting, the pilots claimed.

"As the selected speed was 170 knots, the speed went [...] to 162 knots," said the report, adding, "They [the pilots] could not recognise the speed requirement in icing conditions."

As per the aircraft's manual, they should have maintained 210 knots above 10,000 feet, the report said.

Setting 170 knots was in violation of standard procedure, it added.

The pilots claimed that they were losing altitude but the flight data recorder mentions nothing of that sort.

When the speed supposedly dropped to 152 knots, the pilot disengaged the autopilot and pushed both engines to "emergency" power level, which compromises engine components.

The turbine temperature shot up by over 100 degrees. The temperature should have been 880 degrees Celsius cyclone tops but it shot up to 1,004 and 1,006 degrees Celsius, causing metals inside the engines to melt.

The report states that yanking the plane into emergency power was a deviation from the aircraft operating manual. This power level is for emergencies like trying to avoid a mountain and once this is used, the plane's engines must be inspected and if needed, overhauled.

While explaining as to why they put the engines on emergency mode, the pilots told the investigation committee that there was severe turbulence and "wind shear", or erratic winds over a short distance.

"It was in their words, a life and death situation, still they did not submit any air safety report," noted the investigators. This is a violation of the safety manual.

In addition, the operations manual says that if the plane is pushed to emergency power, it is to be reported to the aircraft maintenance log, but that was not done either.

"Both the captain and first officer mentioned that after landing [at Sylhet], the captain advised ground engineers to check for any defects/fault messages in the audio and radio control display unit [ARCDU], and the airframe [plane's structure]. So there were suspected defects. Instead of writing the details of suspicion they recorded 'nil' in the aircraft maintenance log," said the investigation report.

There is more: the committee found that ARCDU had no message about the engines' parameters having been exceeded and suspected that the pilots had erased it.

"It appears that either no maintenance message was displayed due to an aircraft system glitch or because the message was erased," said the investigators.

Another report by a government agency said, "The pilot tried to hide the whole incident by wiping out the maintenance message on the ARCDU."

HOW THE COVER-UP FAILED

Approximately an hour after the plane landed in Sylhet, Biman Engineering Services got a notification from Pratt & Whitney.

"CAMP Systems Canada, the engine manufacturer nominated vendor, provides Engine Health Monitoring Services for Biman Dash 8-Q400 fleet. [...] the three brand new Dash-8 Q400 aircraft can transmit data automatically," said the report.

This newspaper has a copy of the notification sent by CAMP.

Biman Engineering Services told the Maintenance Control Centre to investigate, but they could not find any pilot report about such an incident or maintenance message in the plane's systems.

"Pilots' 'nil' entry into the aircraft maintenance log and no-fault code or message in the aircraft system created confusion in the engineering services team, especially as it involved simultaneous removal of both engines from only a one-year-old aircraft," said the report.

The next day, Engineering Services contacted Pratt & Whitney, and the airframe manufacturer De-Havilland Canada.

Both analysed the data and recommended grounding the plane and taking the engines out and sending them to an overhaul facility.

But by then, the plane had flown seven flights, any of which could have ended in a disaster, said the investigation report.

Repairing the engines cost Biman Tk 16.5 crore "since the damage of the engines was solely the pilots' fault". That's why the insurance company did not bear the cost, said a show-cause order signed by Biman Managing Director Shafiul Azim on December 20, 2022.

In addition, the plane had to be grounded for three months, leading to a decrease in the number of domestic flights, and depriving Biman of major revenue at a time when the company was still paying monthly instalments and insurance premiums for the aircraft.

The insurance premium of this aircraft was also hiked by a large margin, according to the document.

Insiders said that all the aircraft in the fleet saw a similar hike as a result of this incident.

When asked for an explanation, the pilot blamed the turbulence and wind shear.

In an email sent to the deputy chief of safety on February 13, 2022, Capt Ali Rubyat claimed that they "suddenly got hit by severe wind shear" and "both of us were struggling to keep the aircraft's wings level and prevent altitude loss because of the violent force of the shear".

But multiple investigations called him out on that. "It is evident from a holistic review that the pilot either has no idea about wind shears or is knowingly taking refuge in falsehood," said one report prepared for the government.

The Biman probe stated, "They mentioned the wind shear encounter [...] However, the committee does not consider this as wind shear."

Biman's probe also ruled out illness as a cause of the mistake, saying the pilots were in perfect health.

To the investigators, the pilots repeatedly stated that they did not notice the engine overheating because they were busy trying to control the aircraft.

However, Biman insiders said there are always two pilots inside the cockpit for a reason, one is "pilot flying" and the other is "pilot monitoring". The latter is supposed to monitor all the instruments in the cockpit.

"The loss of situational and system awareness was created partially by the turbulence but mostly by their deviation from the standard operating procedure," said Biman's investigation.

In the show-cause order signed in December, Azim said that the pilot's "unprofessionalism and lack of responsibility can be construed as misconduct".

Biman insiders stated that Capt Rubyat violated sections 29 and 33 of the civil aviation act, which criminalises unsafe flying of aircraft, and risking peoples' lives as a result. It carries the death penalty or life imprisonment and a Tk 5 crore fine.

Furthermore, section 27 has provisions for punishing a pilot who "fails to submit or refuses to submit a report required to be submitted under this act, rules" or someone who files a fake report.

But that did not stop Biman's admin head from including Capt Rubyat in a list of pilots for promotion, as per an order dated January 22, 2023.

Capt Rubyat had been issued a show-cause just a month before. The pilot of the 74-seater Dash-8 was promoted to captain of Boeing 787-8, -9 and Boeing 777 300ER. The 787s can seat up to 298 people and the 777s, up to 419. The prime minister uses these aircraft for her foreign trips.

Biman Managing Director and CEO Shafiul Azim said Biman's Command Board made the recommendation for his promotion.

The Biman's Command Board is composed of the flight operations director, chief of flight operations, chief of technical and other chiefs of departments with the Biman MD as the chair.

The Biman boss said although the Biman's Command Board made the recommendations for Ali Rubyat's promotion, he would not be able to avail the post until he was cleared by the authorities.

"I personally held a hearing of Capt [Ali Rubyat] Chowdhury. As per the protocol of Biman's disciplinary board, we formed a committee for further investigation one week ago which will provide evidence from the technical sides and all issues of the incident [will be presented] impartially and fairly so that no one is punished unlawfully," he said on Wednesday.

A day after getting a call from The Daily Star, the promotion order dated January 22, 2023, was re-issued and signed again with Ali Rubyat dropped.

This newspaper called Azim again to ask why Rubyat's promotion was cancelled. "The Biman management made the decision that the two pilots will not be able to avail any promotion until the departmental action against them is resolved," he said.

When asked why he was considered in the first place, Azim said, "If they were not given promotions, they would have lagged behind."

Capt Ali Rubyat Chowdhury told The Daily Star that since there is still an investigation going on, he will not make any comments.

The Daily Star could not reach first officer Zaman.