How Hasina’s flight was kept off radar

When the air force transporter plane carrying Sheikh Hasina left Dhaka on August 5, it took off as a training flight and turned off its transponders to blur its flightpath and location.
The transponders, which transmit location, heading, altitude and speed, and the automatic geolocator system, were not turned on until the aircraft was close to Indian airspace in West Bengal, several sources told The Daily Star .
The Daily Star obtained a copy of flight AJAX1431’s progress strip from air traffic control. The flight progress strip is a small card which the ATC use to track a certain plane in the air so that planes don’t collide mid-air.
This paper also obtained a recording of the radio communications between the cockpit of the Lockheed C-130 Hercules aircraft and the ATC in Dhaka.
The flight progress strip shows that Hasina’s plane took off from Dhaka’s Bangabandhu Airbase, on the west of Hazrat Shahjalal International Airport, at 3:09pm.
Just 30 minutes prior to this, tens of thousands of protesters took control of the Gono Bhaban, Hasina’s then official residence.
Army chief Waker Uz Zaman was initially scheduled to address the nation at 2:00pm to formally announce Hasina’s resignation. This was later postponed to 3:00pm, but he eventually made his address around 4:00pm.
In an interview with a New York-based nagoriktv.com in the last week of August, Waker said that he did not know that Hasina was flying away.
“When I was holding discussions with the political parties, somebody informed me that she is going to exit the country, she is on the run. I did not know that she was leaving the country. I think that if she had stayed, it could have been a risk to her life. Definitely, nobody would have wanted an extra-judicial killing to have happened. The situation was extremely volatile,” he said.
The plane turned on its transponders and automatic geolocator system when it reached waypoint “BEMAK” on Dhaka-Kolkata route. The aircraft suddenly showed up on radar. It first headed towards Kolkata before changing course for Hindon Air Force base in Ghaziabad, 30km from the Indian capital, according to a screen grab of the radar screen at the Dhaka airport.
Aviation experts said that it was likely that the plane made the detour, by going towards Kolkata first instead of flying straight to Delhi, because it wanted to spend as little time as possible in Bangladesh airspace.
The Dhaka to Delhi route flies over Rajshahi and requires several minutes more in Bangladesh airspace than the Dhaka to Kolkata route.
Indian Foreign Affairs Minister S Jaishankar told the Rajya Sabha on August 6 that Hasina had sought approval to come to India on a “short notice”.
According to the flight progress strip, Indian authorities were notified of the plane entering its airspace.
Hasina’s flight was given squawk code 4131, a unique four-digit code assigned by the ATC to each aircraft operating in its airspace.
Before taking off, the crew manually enters this code into the aircraft’s transponder.

When a flight plan is approved, the code is sent to the destination air traffic controller, in this case it was Kolkata.
Civil aviation sources said there is a direct hotline between Dhaka and Kolkata’s air traffic control to notify each other about approaching planes.
Even though the plane was invisible to secondary radar, used by ATCs, the cockpit crew maintained continuous communication with different air traffic controllers, including the Hazrat Shahjalal International Airport’s traffic controller, and most likely the Kolkata area air traffic controller.
The recording of the radio communications between the C-130 and the ground controller at Dhaka reveals that flight AJAX1431 chose taxiway South Alpha to get on runway 32 from Bangabandhu Airbase.
The ground controller warns the plane that two Antonov An-32s were there and to taxi with caution.
The plane was later cleared for an initial altitude of 20,000 feet by the ATC.
“AJX 1431 […] cleared for take-off, after take-off, left-turn 238 [heading], continue climb [to] flight level 200 [20,000 feet], we are rolling,” said the pilot as he repeated the controller’s instructions as required and notified the ATC that the plane was taking off.
The tower responded, “Roger” and Sheikh Hasina’s flight was in the air.

After AJAX1431 crossed 4,000 feet, the pilot contacted the Dhaka area control centre.
“Dhaka control AJX 1431, crossing 110 [11,000 feet] continuing [to] 200 [20,000 feet] and we will be just 15 miles left deviation,” informed the pilot.
“Fifteen miles left deviation approved,” said the controller in Dhaka.
The crew eventually sought clearance for 24,000 feet, which was approved by Dhaka ATC.
The ATC then also alerted the cockpit crew about traffic, an Airbus A320 heading for Dhaka. It said the Airbus was above them and was descending to 26,000 feet.
Soon afterwards, Dhaka ATC said, “AJX 1431 change to Kolkata control”, which means it asked the crew to get in touch with the Kolkata area controller and announce its arrival. This is usually done when the flight is close to the border, sources said.
Air Commodore AFM Atiquzzaman, member (operations & planning) at the Civil Aviation Authority of Bangladesh was at the ATC tower when Hasina’s plane took off. He saw the plane take to the sky.
“At that moment I had no idea who was inside that flight. I was there in the tower just doing my normal duty when I saw an Air Force training flight taking off. I did not know of course who was inside,” Atiquzzaman told The Daily Star.
According to a report of India Today, after Hasina’s plane crossed the border, it was escorted by two Dassault Rafale fighter jets of the 101 squadron at Hashimara airbase in West Bengal.
The fighters were waiting for the C-130.
India Today on August 6 said the Indian authorities started monitoring the flight around 10km from the Indian border with Bangladesh.
Sources claimed that neither Hasina, nor her sister Sheikh Rehana, or the flight crew and Special Security Force (SSF) members went through immigrations before departing Dhaka.
Hasina was carrying a diplomatic passport, while Rehana had a British passport.
According to Indian media, the plane landed at Hindon airbase at 6:15pm (Dhaka time).
Hasina was then taken to a safe house provided by the Indian government in Noida, Uttar Pradesh province.
The SSF members and the crew flew back to Bangladesh a day later.