Around mid-February in 2019, a Bangladesh Biman pilot felt something hit his aircraft while taking off from Dhaka's Hazrat Shahjalal International Airport.
Assuming it was a bird, the pilot immediately contacted the airport tower asking them to inspect the runway and check if anything was there.
Upon confirmation that a bird, which might have hit the plane, was lying dead on the runway, the pilot decided to make an emergency landing for the safety of the several hundred passengers on board.
"The bird strike could have caused major damage to the aircraft had it hit the engine. Thank God, it was nothing major," the pilot of the KSA-bound flight told The Daily Star recently.
Bird strikes are a common phenomenon at airports around the world.
To tackle such incidents -- often leading to flight cancellation, damage to the aircraft engine or, in worst case scenarios, loss of life due to crash landing -- airport authorities across the globe use modern and conventional technologies to drive the birds away from key aviation installations.
The HSIA also has such equipment but they are barely functional.
The two automated bird deterrents installed on the runway have remained out of service for more than seven years. One of them was to drive the birds away by using laser beams while the other sends sound signals to deter the birds, airport sources said.
Besides, four out of six guns meant to scare the birds away from the busiest international airport of the country have also been out of order for the past six years.
Pilots and aviation experts termed the situation unacceptable and blamed the Civil Aviation Authority of Bangladesh (CAAB) for its sheer negligence.
"The CAAB is earning over a thousand crore taka every year, but it's a shame that they could not afford a few guns or modern deterrents to ensure safety of aircrafts from bird strikes," a Bangladesh Biman pilot told this correspondent.
"The price of CAAB slacking off has been heavy," he fumed.
Wishing anonymity, the pilot said an aircraft of Biman narrowly escaped a major accident in 2019, adding that he was forced to land a few minutes after take-off after he felt a bird hit one of the two engines.
Talking to The Daily Star yesterday, aviation expert Kazi Wahidul said, "Bird strike is a serious issue at the Dhaka airport. We have tried to raise it several times before the Civil Aviation Authority.
"Guns of primitive ages will not work to deter birds. CAAB should immediately take urgent measures to install modern equipment to address the bird strike issue."
M Mokabbir Hossain, Biman's CEO and managing director, said at least 20 of our aircrafts suffered bird strikes at the HSIA in 2019.
Other airliners have also suffered similar accidents, sources say, but the HSIA authorities could not give an exact number.
According to pilots, costly repairs are required if birds strike the engine, the fuselage below the wings or the windshield.
The annual cost that commercial planes bear worldwide due to bird strikes is estimated around $1.2 billion, according to information available on aviation websites.
HSIA PRONE TO BIRD STRIKE
Sources of different airlines said the HSIA has several water bodies and wetlands in and around it, which is inviting to birds. Besides, the risk of bird strikes increases in winter when migratory birds flock the area, they said.
HSIA sources said there is a landfill of the Dhaka North City Corporation at the north end of the airport and birds are usually seen in the sky surrounding it in search of food. Planes usually fly over that exact area during final approach.
Statistics of the International Civil Aviation Organisation show that 90 percent of bird strikes happen around airports.
The majority of bird strikes are caused by unknown species while perching birds account for 22 percent, shore birds for 11 percent, raptors -- such as hawks, eagles and vultures -- for nine percent, pigeons, doves and swifts another nine percent, and ducks, geese and swans account for just two percent, according to the website of a company which works on airport bird control.
In the first meeting of the Asia Pacific wildlife hazard management working group held in Thailand in 2019, Bangladesh presented its experience on the establishment of a National Civil Aviation Wildlife Control Committee.
It was said in the presentation that bird strikes on and around airports in the country were a common phenomenon and its continued rise had put airport operators to look for effective mitigation measures.
According to different online reports, incidents of bird strikes at different airports in South Asia, including in India, has increased in recent years.
WHAT AUTHORITIES SAY
"We have six guns to deter birds," Group Captain AHM Touhid-ul Ahsan, director of the HSIA, said recently. "But four of them have been out of service for long and have been rendered irreparable. Our bird shooters deter birds with the two other guns."
Two shooters move from one corner to another of the airport when they see birds in the sky, he added.
Touhid said bird strike is a global problem, adding that the process of buying new guns was underway. "We have applied to the home ministry for a licence in June [last year]."
He also admitted that the two automated deterrents have been out of order "for a long time".
"We have started the process to purchase the modern Bird Monitoring and Control System to automatically detect and deter birds at the airport," said Touhid.
Asked whether the absence of any automated device and shortage of guns pose serious risks to aircraft operating at the HSIA, Touhid said, "Birds do not fly around the runway in flocks. When one or two birds fly individually, bird shooters rush to deter them.
"The shooters also work in coordination with the airport control tower. Sometimes birds are killed and sometimes they are deflected with shots in the air."
Sources with knowledge of how it works said the sound of gunshot often does not work at Hazrat Shahjalal International Airport as birds of the area have become used to it.
Mokabbir Hossain of Biman said they have been informing CAAB about the matter.
"When you follow one specific method to drive away birds, it does not work after some days as birds usually adapt to it. Therefore, there should be multiple methods to get effective results," he said.
Aviation experts said CAAB should also take measures to encourage birds to seek alternative nesting and feeding grounds by applying a number of methods, which include removing food sources such as seed-bearing plants, food sources for the insects that birds eat, covering ponds with netting to prevent birds from landing and clearing bushes and trees that offer attractive nesting sites.
Air Commodore Md Khalid Hossain, member (operations & planning) at the CAAB, told this correspondent recently that they were trying to find a modern and better approach to resolve the problem.
"A committee is working to finalise tender specifications for procuring a Bird Monitoring and Control System. We will go for bidding very soon after getting the report from the committee," he said.
Asked why the CAAB was not repairing the guns and other existing equipment to deter birds, he said they were facing "various difficulties" including trouble with the agencies that supply the equipment.
"To be very honest, the existing system was not very effective," he added.