A single word can change it all
By Johan Lottering
A valid Language Proficiency rating is one thing. Interpreting ATC communications correctly is another and depends on a variety of factors. The first is respect. Ironically, inexperienced aviators least able to rely on their 'natural prowess' are often the ones who do so. The likes of these often do not bother to study either the aerodrome layout charts or the VFR arrival or departure routes and procedures - published in the AIP. Correct read-back of ATC or Ground Control instructions largely depend on anticipation. The only way to overcome rustiness or inexperience is through thorough preparation and intensive prior study.
Consulting the relevant Notams and obtaining the necessary METAR and TAF is just as vital. Many chaps responsible for heading deviations, altitude busts and runway incursions are not only guilty of inattention but underestimating the task at hand and of trying to listen with their mouths open. Once inside controlled airspace it is simply vital to give the highest priority to listening out. The chaps in the airlines, when operating below 10,000 feet, do not adhere to a "sterile cockpit" protocol for nothing. Once within controlled airspace it is absolutely vital to limit internal communications with fellow-flyers to the essential.
Misinterpreting or omitting a single word, such as "north" in a ground-clearance had once led to a major airport disaster. This was exacerbated by a crew with a heavy accent turning right instead of left. Within the 'laid-back' airport ground control climate it made matters worse. Nobody could either spot or catch the crew's mistake.
The Linate Airport disaster in Milan had actually been cultivated for years without anyone lifting a finger to avoid it. No-one neither noticed nor intervened to alleviate latent conditions culminating in a collision between a Scandinavian Airlines MD-87 taking off and a German Cessna 525 taxiing down the runway at 06.10:21 on October 8, 2011. The events were a virtual carbon copy of the world's worst air disaster in Tenerife on March 27, 1977 where 582 people perished as a KLM Boeing 747 taking off collided with a Pan-Am B747 taxiing down the runway at Los Rodeos Airport in conditions of congestion, poor visibility and language difficulties. All 110 aboard the Scandinavian Airlines Flight 686 underway to Copenhagen, all four inside the Cessna going to Paris plus four in the luggage building died.
The Scandinavian air crew would be exonerated in the Final Report of January 20, 2004 issued by the Italian Authorities (ANSV). Several findings would correlate with the systemic error model of Dr James T. Reason of the University of Manchester whereby disaster occurs when successive weaknesses or breakdowns in safety barriers line up like holes in a Swiss cheese to link potential hazards with actual losses.
The airport had been operating without an Air Surface Movement System (ASMS) since 1999. Ironically elements to replace the old system had indeed been available, but not yet installed. The guiding signs on the taxiways did not meet international regulations, were badly worn and obscured. There were no signs the erring German crew could recognise.
Repeated reports by them at point "Sierra 4" were disregarded by the Italian ground controller. The position was simply not on his map. The controllers had become accustomed to the "meaningless" S-signs posted all over the airport and which had been there for years.
Motion sensing alarms supplementing the ASMS had been deactivated years ago after chronic false alarms by stray animals or vehicles. The ground controller was unable to switch cross-bars, which would have prevented inadvertent entry onto the wrong taxiway, on and off. The German pilots had omitted the word "north" from their original taxi read-back. Language accent differences had caused the crew to shuttle from a state of focused attention to diffused attention (ANSV report, p. 126). They had turned right instead of left and gotten lost. It was as simple as that. Neither pilot was certified for Category IIIB operations and incumbent Low Visibility Procedures (LVP).
By implication neither could only operate in conditions of 550 Runway Visual Range (RVR) whilst it was 200 meters visibility on average. In fact, the RVR for the MD-87 was 225 meters at the touch-down zone, 200 at mid-zone and only 175 at stop-end zone. The pilots had been rented by a company involved in selling the aircraft and were under immense commercial pressure to perform.
Furthermore, the airport taxi-way diagram did not conform to ICAO clockwise logic. Neither the Aeronautical Information Publication nor the Jeppesen Airway manual airport layouts correlated with the actual airport markings.
Much progress has since been made regarding Low-Visibility and Reduced Visibility Take-offs in South Africa (AIP ENR 1.8.4 & CAR 91.08.1-4). Practical Operating Recommendations during LVP would, according to Understanding CATS & CARS, fifth edition, by Phillip Marais (p. 20) include a mandatory thorough review and briefing of the airfield layout and expected taxi route; slow taxi speed with deliberate manoeuvring; caution to ensure situational awareness is not lost and to immediately stop on a taxiway with park-brake set whilst notifying ATC; to study the airport diagram chart during pre-flight briefings; doing checklists when the aircraft is stationary; using external lights to see and be seen; transponder setting requirement being reviewed and a proper task distribution where one pilot is responsible for external lookout at all times and the other for chart reading and providing on-ground navigational assistance.
According to an Australian air safety analyst Dr Suzanne Kearns imminent error can only be detected in time against a backdrop of accuracy or perfection. From a safety management point of view the challenge is not only to be reactive, but proactive and predictive.
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