Qantas Mayday

 Qantas Mayday

 

On January 18, 2023, Qantas Airlines QF144 landed safely in Sydney around 3:30 after the pilots issued a very rare Mayday call. QF144 declared a Mayday call, later downgraded to a PAN call, after suffering engine failure in flight. Engine failures in flight are extremely rare, and ‘quite serious’, according to air experts. (Parkes-Hupton, 2023)

 

The engine failure was the first in a series of three different Qantas incidences involving the Boeing 737 for two of them, and a Boeing 717 on the other, within just a few days span. On January 19^th, the day after the engine failure, a mechanical issue with a flap was reported on QF101. Then, on January 20^th, another Qantas aircraft, QF430, had another minor engine issue prompting the pilots to return back to Melbourne. (Cross, 2023)

 

What happens when an engine fails in flight?

Typically, in flight, both engines generate the same amount of thrust. If one engine malfunctions, there is an imbalance in the thrust. This will cause the movement of the aircraft to drastically change and yaw to the side of the affected engine from the power of the functioning engine. To counter this effect along the yaw axis, a force must be involved to block the momentum from happening. This is where the rudder, or tail section comes in. The pilot’s use their feet and press on the rudder pedals to push the rudder towards the side of the operating engine to control the yaw. Since the incident involving QF144 happened at cruise altitudes, the aircraft descended to the One Engine Inoperative (OIE) ceiling of 20,000 feet where the air is denser than it would be at cruising altitudes, to safely control the aircraft back to the airport. (Maaz, 2022)

AD on CFM Engines

Back in June of 2022, CFM found defects in 12 of their Leap-1A models. They found possible defective internal components within that could potentially cause engine failures. This prompted the FAA to issue an Airworthiness Directive (AD) for the issue. The new issue involves manufacturing defects of engine spools and disks that could cause them to fail. The AD states, “This AD was prompted by a manufacturer investigation that revealed that certain high-pressure turbine (HPT) rotor stage 1 disks (HPT stage 1 disks) and a stages 6-10 compressor rotor spool were manufactured from material suspected to contain iron inclusion. This AD requires the replacement of certain HPT stage 1 disks and a stages 6-10 compressor rotor spool.” (FAA, 2022) I only bring the AD into the equation for two reasons: 1. The effected engines were CFM engines as was the one that failed on flight QF144, only a different model, and 2. it shows how the smallest details like a chemical element can alter the performance and integrity of a component in such an impactful way. There is an ongoing investigation on the matter, and soon we’ll have some answers that caused the in-flight incident. 

 

References

Aircraft Science. (2022, October 12). How Flight Controls Work | Part 8 : Yaw Control. YouTube. https://www.youtube.com/watch?v=Y63sL1EFWDs

australianaviation.com.au. (2017, July 17). Qantas repaints first Boeing 737-800 in new livery. Australian Aviation. https://australianaviation.com.au/2017/07/qantas-repaints-first-boeing-737-800-in-new-livery/

Cross, L. (2023, January 20). Qantas Issues Statement Following Spate of Technical Issues. Airways Magazine. https://airwaysmag.com/qantas-safety-statement/

Federal Aviation Administration. (2022, July 18) Airworthiness Directives; CFM International,

S.A. Turbofan Engines. https://www.federalregister.gov/documents/2022/07/01/2022-14212/airworthiness-directives-cfm-international-sa-turbofan-engines

Joshi, Guarav (2023, January 20). Three in Three Days: Qantas Flight Turns Around To 

Melbourne, Simple Flying. https://simpleflying.com/qantas-flight-turns-back-sydneyjanuary-20/

Maaz, Mohamed, A. (2022, August 20) What Happens When An Aircraft’s Engine Fails: A     

Pilot’s Perspective. Simple Flying. https://simpleflying.com/engine-failure-pilot-perspective/

McGuire, A. (2023, January 19). Qantas flight to Fiji forced to turn back after ‘potential mechanical issue.’ The Sydney Morning Herald. https://www.smh.com.au/business/companies/qantas-flight-to-fiji-forced-to-turn-back-after-potential-mechanical-issue-20230119-p5cdxl.html

Parkes-Hupton, H. (2023, January 19). Qantas QF144 engine failure uncommon and “quite serious”, according to air experts. ABC News. https://www.abc.net.au/news/2023-01-19/nsw-qantas-engine-failure-explainer/101870742