On July 23, 2014, TransAsia Airways ATR 72-500 (72-212A), manufactured by Aerospatiale in Toulouse, France, in 2000 with 58 occupants onboard was destroyed in an accident near Magong Airport (MZG), Taiwan. Flight GE222 had departed from Kaohsiung International Airport (KHH) on a scheduled domestic flight to Magong Airport, Penghu Islands.
The airplane crashed during a go-around following a failed attempted landing at 19:06. 44 passengers and the 4 crew members perished, while the remaining 10 passengers sustained serious or minor injuries.
On February 4, 2015, a Transasia Airways ATR-72-600, manufactured by Aerospatiale in Toulouse, France, in 2014 with 58 occupants onboard was destroyed in an accident in Taipei just after take off. Flight GE235 had departed from Taipei Sung Shan Airport (TSA) on a scheduled domestic flight to Kinmen Island (KNH).
The airplane took off from Taipei-Sung Shan Airport’s runway 010 at 10:51 AM local time. While climbing, the aircraft started to loose altitude and impacted a bridge just before impacting into the Keelung River and came to rest inverted. Only 15 occupants survived.
Both fatal accidents suffered by the same carrier and with similar aircrafts manufactured by the same corporation occurred within seven months. Is it just a stunning and disgraced coincidence? Let’s see what we know from each event.
On December 26, 2014, the Aviation Safety Council (ASC) of Taiwan published an exhaustive Preliminary Report. However, no analysis has been released by the ASC so far. It is expected that the ASC will present a draft of final report to the Investigation Accredited Representatives by June 2015, publication being expected in October 2015.
Meanwhile, our own technical experts have already revealed certain factual findings that might implicate the aircraft in the causal events that led the aircraft to collide with the terrain (in a type of event that is known as CFIT or Controlled Flight into Terrain).
According to the disclosed data, GE222 departed the runway axis during a second landing attempt. While in landing configuration, the aircraft continued final approach, around 300 meters left of the runway axis, impacting with the terrain due to the lack of visibility.
Modern aircrafts, such as the ATR72-500, are equipped with systems that alert the crew in different situations that implicate risk of impacting with the terrain. These systems work with GPS facility and radio altimeter information, along with other data sources. They can be considered one of the last lines of defense with which the aircraft is fitted against dangerous operation against the ground.
One of the several protections/modes against terrain, while in landing configuration, is the Terrain Clearance Floor (TCF) mode, which creates an increasing terrain clearance envelope of 360º around the airport runway directly related to the distance from the runway. The alert is based on current aircraft location, nearest runway centre point position and radio altitude. TCF is activated during takeoff, cruise and final approach.
This protection can be represented like an inverted cone around the runway, and includes all the surrounding terrain specification (slopes, changes of level, hills, etc.). The following diagrams express it more clearly:
This particular Transasia aircraft was equipped with a Honeywell EGPWS MARK VIII. According to the maintenance records, the EGPWS database was updated on April 23, 2014. The version was 470, which was the latest database version before occurrence. It includes the runway data of Magong airport.
According to the EGPWS, in the accident scenario, the EGPWS should have cleared a TCF alarm, in the form of a light in the cockpit panels, as well as an auditory warning by way of a synthetic voice: “Too Low Terrain” and later “Terrain Ahead – Pull Up”. These alarms should have been automatically activated due to the fact that the aircraft started flying below the TFC cone.
However, simulations performed after the accident by Aerospatiale in Toulouse (France), as well as data downloaded from the non-volatile memory from the EGPWS device itself, showed that, in the particular scenario of the Magong Airport, the TCF would not activate. This would be due, according to the ASC Preliminary Report, to the operational limitations of the software version (version 011) installed in the EGPWS equipment.
According to simulations performed by Honeywell, this operational limitation would have been resolved (and therefore the TCF alarm activated in a scenario identical to this accident) if the software installed would have been version 022 or newer. This software version has been available since 2004 (some 4 years after the aircraft’s manufacture) but it would not be compatible with the hardware P/N installed in this ATR72). Attachments 3-8, 3-9 and 3-10 of the Preliminary Report, which include Honeywell Analysis of Enhanced Ground Proximity Warning System, Honeywell Service Bulletin, ATA No. 965-1180/1190/1210/1220/ 1610-XXX-34-33 (Pub. No. 012-0709-133), as well as Honeywell Service Information Letter (SIL NO. EGPWS-MKVI-MK VIII-07), do not seem to be available for the time being.
The fact is that in modern aircrafts, crews know that they have full-time protection, particularly during final approaches in low visibility conditions. It looks quite surprising that this aircraft was equipped with a system that would not provide the protection that was reasonably expected.
If the system had been properly updated, the TCF warning would have been activated (as recognized by both the aircraft and the EGPWS manufacturer) and the accident could have been avoided. These facts, pending further investigation and analysis by our experts, may lead to the potential liability of both manufacturers.
The Transasia airplane took off from Taipei-Sung Shan Airport’s runway 10 at 10:51 local time and turned right, climbing to an altitude of 1350 feet. Instead of continuing the climbing right hand turn, the airplane turned left and began losing altitude and speed. Meanwhile, about 10:53, the flight contacted the Sung Shan Tower controller declaring a Mayday and reporting an ‘engine flameout’. It then turned to the right before banking almost 90 degrees left again as it hit a taxi on a viaduct. Parts of the left wing broke off upon hitting the barrier of the viaduct. The airplane impacted the Keelung River and came to rest inverted.
Only 15 persons out of the 58 occupants survived the crash.
The first ATR 72-600 flight took place on July 24, 2009; civil certification was awarded by EASA in May 2011. ATR 72-600 is equipped with Pratt & Whitney Canada PW127M engines.
According to the information appearing in the media, the crew reported an emergency immediately after takeoff, informing of a possible flame out (extinction) of both engines. Other sources mention the possibility that the engines’ propellers would have been feathered (change of angle position which leaves the engine with no actual thrust).
The following picture shows the feathered position in a Hercules C135 military transport aircraft.
If, for whatever reason, during a critical phase of flight such as take off, the aircraft suddenly losses thrust due to the transition of the propellers to their feathered positions, it will almost instantly lost aerodynamic lift and stall.
The video footage appearing in the media shows how the aircraft was descending at low speed in a nose up attitude, before dramatically banking to the left and impacting into the river. Those are indications of an aerodynamic stall, likely produced by a loss of thrust. The available photographs of the debris also seem to indicate that, in fact, the propellers were feathered at the moment of impact.
Other sources indicate that the crew might have switched the operating engine after a failure of the other engine. This could explain the total loss of thrust and the feathered propellers. However, this is not the first occasion in which this situation would have happened with this particular aircraft.
C) Similarities and Liabilities
Both accidents present several common factors: a) same aircraft manufacturer; b) very similar model; c) same carrier; e) both domestic flights; d) a potential technical malfunction as a causal and/or contributory factor.
The carrier’s liability regime will be, in most cases, subject to Taiwanese law, but this will also depend upon the contract of carriage of each passenger. Passengers who were engaged exclusively in a domestic flight will be subject to domestic Taiwanese law; those for whom this flight was part of an international round trip, international treaties will likely apply.
In general, we can consider that both domestic (Taiwanese) and international (particularly through the 1999 Montreal Convention) regimes provide a strict and unlimited liability system, with some exceptions and possible limitations.
It must also be considered that the eventual implication of the aircraft manufacturer, alongside other parts’ manufacturers (such as Honeywell for the EGPWS or Pratt & Whitney for the engines), potentially provide remarkable jurisdictional alternatives for the relatives of the deceased passengers of both accidents, as well as for the survivors.
This will be particularly true for those passengers who were only involved in domestic carriage transportation. Passengers whose travel was limited to Taiwan should be able to sue ATR, any other parts manufacturer, and the carrier, in France. The presence of US and/or Canadian defendants could potentially enhance the assessment of damages.
BCV Lex, a Global Justice Network member, is already representing relatives of victims of the flight GE222, and is studying the different jurisdictional venues available.