Biman plane loses wheel mid-air: initial analysis points to bearing failure

One of the left wheels of the main landing gear of Biman Bangladesh Airlines' Dash-8 aircraft detached due to a "bearing failure or malfunction", the national flag carrier said today.

Biman, in a press release, said that preliminary observations pointed to bearing failure as the cause of the wheel detachment on the aircraft, which had departed from Cox's Bazar for Dhaka on Friday.

However, the exact cause of the failure will be known after an investigation, the press release said.

Biman has already formed two committees to ensure safety and conduct a thorough investigation into the incident.

The flight BG436 of Biman landed safely at Dhaka airport despite losing a wheel from its left-side main landing gear shortly after take-off from Cox's Bazar. The aircraft was carrying 71 passengers.

Following the review of the incident, Biman authorities today said that the aircraft -- a Dash-8 Q400 model manufactured by Canada's De Havilland Aircraft Company -- may have experienced a bearing malfunction that led to the dislodging of the wheel or tyre, which is what occurred in this case.

In response, Biman has contacted the aircraft manufacturer and requested it to send a technical team to Dhaka. The Canadian company confirmed that its specialised team is on the way to Dhaka, according to the release.

As an immediate precautionary measure after the landing, Biman's engineering division inspected all wheels of all aircraft currently stationed in Dhaka.

Biman has announced the formation of two separate committees in response to the incident. One is a three-member Safety Investigation Committee led by the Chief of Flight Safety.

Additionally, under the Directorate of Engineering and Material Management, Biman has formed another three-member investigation committee.

The investigation committees will determine the root cause of the incident. They will also examine the maintenance conditions and records, and provide recommendations to prevent recurrence of such incidents.

Biman said that the investigation reports will be submitted within three working days, the release further said.

Biman said Ethiopian Airlines, one of the major operators of Dash-8 Q400 aircraft, currently has 31 such aircraft in service.

In the past three years, the airline has experienced four similar incidents like Biman.

Quoting De Havilland, Biman described the Dash-8 Q400 aircraft as "extremely safe".

From 2013 to 2017, a total of 59 wheel-related incidents were recorded for this aircraft model.

The airline explained that the landing gear system of the Dash-8 Q400 includes redundancy. Therefore, if a wheel unexpectedly fails, it does not compromise flight safety, the press release.

Typically, in the design of any commercial aircraft, redundancy or backup systems are incorporated to ensure the safe operation of each component related to flight safety.

Similarly, each landing gear of the Q400 has two wheels. This allows the aircraft to land safely in emergency situations even if one wheel fails or experiences issues, Biman authorities added in the release.