4 July, 2022


SriLankan Airlines: UL 504 The ‘Overlooked’ Threat Of The Possible Midair Collision

By Marlon Dale Ferreira –

Marlon Dale Ferreira

The recent hype that was created on social media pertaining to the possible midair collision that was avoided between SriLankan Airlines flight UL 504 travelling from London to Colombo and a British Airways aircraft flying over Turkey, has taken a different twist with substantial evidence emerging now that the national carrier of Sri Lanka could in fact have faced a catstrophere.

Whilst the pilots of UL 504 reported that a possible collision was avoided in their submitted Air Information Report, the Management of SriLankan Airlines was quick to downplay the episode and issued a media release stating that there was no risk of a midair collision due to the vigilance of the pilots and state of the art equipment and surveillance systems on board the aircraft, which enabled a safe passage for UL 504.

Colombo Telegraph completing an extensive investigation published a story titled “SriLankan Airlines: Management Confirms No Risk Of Midair Collision” on the 17th of June 2022, which provided a local aviation expert’s opinion and a technical description of the probable eventualities, confirming that there was no risk of a midair collision, based on both aircraft being fixed with Traffic Collision Avoidance Systems (TCAS).

However whilst this explanation could be deemed accurate, it could be confirmed that in order for the TCAS to work both aircraft require its transponders to be fully functioning.

This was highlighted by a pilot of a foreign airline who after reading our earlier published story, contacted Colombo Telegraph and conveyed the following excerpts from the Airbus Pilots Flight Operating Manual (FOM)

The Airbus Pilots Flight Operating Manual (FOM) states: The Traffic Collision Avoidance System(TCAS)

1. Detects and displays surrounding aircraft that have a transponder.
2. Calculates and displays possible collision threats.
3. Triggers vertical speed orders, in order to avoid collisions.

It is a fact that the British Airways aircraft did inform Ankara’s Air Traffic Controller (ATC) that it was having issues with its transponder sending out intermittent signals.

This conversation between Ankara’s ATC and the BA aircraft was heard by the pilots of UL 504 who in fact did report that in their submitted post flight Air Information Report.

Whilst many of the experts spoken to claimed the the last line of defense of averting a midair collision was the TCAS, then it could be argued that with Ankara ATC’s undetection of the BA aircraft on its radar, a possible midair collision could have in fact taken place due to TCAS not working due to BA aircraft’s transponder being inoperative.

If in the event the pilots of UL 504 did follow Ankara’s ATC’s instructions and climbed to flight level 35,000, the undetected BA aircraft flying without a fully functional transponder could have breached TCAS, which now has been established as the last line of defense from preventing a midair collision taking place.

This now certainly takes another twist with all investigative parties such as both airlines, the regulatory bodies of the respective countries and even the aircraft manufacturer investigating this matter fully in order to mitigate such situations and prevent repetitive safety lapses from taking place.

This episode is also bound to be used in future as a part Crew Resource Management (CRM) training workshops, which will focus on the importance of enhancing skills such as “Situational Awareness” and “Decision Making”, which are key attributes needed in any professional pilots’ flying armoury.

At the end of the day, despite this episode reaching widespread publicity in many forms on several media platforms, the most important thing is that the skies continued to remain safe and that the competence of the UL 504 pilots be commended for being both situationally aware and with the decisions taken during that brief inflight period, when flying over the skies of Ankara, Turkey.

Whilst both aircraft reached their destinations safely, Sri Lankan Airlines Flight Operations Training Department ought to be commended too for the consistent high standards that they have maintained over the years.

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Latest comments

  • 1

    I am glad the author changed the article, from what he wrote earlier. What he wrote earlier was insulting to the Co-Pilot who wrote the report.

    • 1

      Whatever the case, the article is a welcome fair and objective comment.
      And not many here correct their stories.

      • 0

        Absolutely true !

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