KATHMANDU: Four pilots and three air traffic controllers have been taken off the roster after Boeing 757 operated by the Nepal Airlines and a domestic aircraft of Simrik Air engaged in a near miss incident, raising the spectre of collision, it has been revealed.

The Civil Aviation Authority of Nepal has decided to ground pilots and ATC officers after Doha-bound Boeing flight came close to a descending Simrik Air plane over Bharatpur area on September 4 giving a scare to about 200 passengers on board the two aircraft, according to CAAN.

“Pilots in command of the both aircraft and three ATCs handling air traffic system at the Tribhuvan International Airport at the time of incident have been grounded on Tuesday for further investigation,” officials at the aviation regulatory body confirmed.

A committee led by Shobha Shrestha, Chief at CAAN’s Department of Air Navigation Services, comprising Captain Deepak Kumar Lama and CAAN Manager Subash Jha as member of the panel, has been assigned to probe into the incident.

A source close to Air Traffic Services Department confirmed that the Traffic Alert and Collision Avoiding System (TCAS) installed in both the aircraft dispatched resolution advisory after the domestic aircraft returning from Bhairahawa to TIA and the aged Boeing 757 of the country's national flag carrier came close to each other violating the 1,000 feet separation rule.

“The pilots, however, manoeuvred themselves to avoid a disaster after getting resolution advisory in the system,” TIA source said, adding that the Simrik Air pilot pulled his aircraft up while the Boeing captain reduced plane's altitude to avoid a collision.

A source close to ATC tower at TIA said that the Boeing commanded by Senior Captain D N Rana along with co-pilot R Maharjan reportedly ignored the tower’s request to descend from the height of 12,500 feet as Kathmandu-bound Simrik air was preparing to descend from the height of 13,500 feet above Bharatpur in Chitwan.

“TCAS resolution advisory has surfaced after Boeing attempted to take more height coming close to the domestic air carrier piloted by Captain K Silwal along with co-pilot A Manandhar,” an ATC told THT Online.

As per the Standard Operation Procedure, both pilots must have followed the resolution advisory (RA) to take an immediate decision.

The probe panel has already started reviewing and analysing the recorded radar and audio data. According to a member of the committee, the team will also review relevant air traffic control procedures as well as interview with the air traffic controllers and flight crew.

“Pilots and ATCs won’t be allowed to continue their duty until the investigation is completed,” CAAN officials added.

According to them, it is the first committee formed to probe an air miss event in CAAN's history while ATCs have also been taken off the roster probably for the first time to investigate such an incident.