By Dr Simon Bennett, Director, Civil Safety and Security Unit, University of Leicester.
Following the 8 March, 2014 disappearance of Malaysian Airlines flight MH370 a respected aviation journalist said: “Catastrophic things do not happen to modern aeroplanes. They just don’t”. Well, they do. Since 1948 around eighty aircraft have been declared ‘missing’ where not a single corpse, skeleton or scrap of metal has been found. Aircraft can fall from the sky or vanish for many reasons.
In the 1950s metal fatigue – at that time an unfamiliar failure mode – destroyed several Comet airliners. In September 1970 the Popular Front for the Liberation of Palestine hijacked four commercial passenger jets to Dawson’s Field, a remote desert airstrip in Jordan. The aircraft were destroyed. In July 1988 274 passengers and 16 crew died when an Iran Air Airbus was destroyed by a surface-to-air missile launched by the American cruiser Vincennes. In December 1988 a bombed Pan Am Boeing 747 fell onto the Scottish town of Lockerbie, killing 243 passengers, 16 crew and 11 residents. In 1996 a TWA Boeing 747 disintegrated killing 212 passengers and 18 crew. A four-year investigation concluded the ‘probable cause’ to be a fuel-tank explosion. In September 1998 a Swissair MD-11 crashed into the sea off Nova Scotia killing 215 passengers and 14 crew. The disaster was attributed to degraded avionics (due to fire) and loss of crew situation awareness. In 1999 an Egypt Air Boeing 767 speared into the Atlantic killing 203 passengers and 14 crew. The Americans blamed a suicidal pilot. The Egyptians the aircraft. In 2009 an Air France A330 disappeared between Rio and Paris killing 216 passengers and 12 crew. Having lost situation awareness (partly due to inadequacies in the aircraft’s avionics) the pilots were unable to recover the aircraft from a high-altitude stall. They fought to regain control until they hit. It took two years to find the ‘black-boxes’ (actually orange). The initial search area for MH370 was 15-20 times the size of that for AF447.
Coverage of the MH370 episode suggests we have unrealistic expectations. While air travel has an enviable safety record, it is not 100% safe. If we look at aviation through the prism of total safety, we are going to be disappointed. Flying several hundred people six miles above the earth at close to the speed of sound in an environment subject to turbulence and low temperatures (-55°C) in a pressurised aluminium tube packed with fuel, generators, air-conditioning units (that run hot), batteries and cabling is not without risk. Aircraft are complex machines whose component parts can interact in unexpected ways. In the case of TWA Flight 800 a spark from a cable ignited an explosive fuel-air mixture. In the case of Swissair Flight 111 the aggressive electrical fire so preoccupied the Captain and First Officer that they lost situation awareness. Had the flight crew maintained situation awareness they might have been able to save the aircraft. Had such a fire afflicted an aircraft with a three-person flight-deck (Captain, First Officer and Flight Engineer) there might have been sufficient human resources to extinguish it and compensate for the degraded avionics. The two-person flight-deck is a cost-saving measure. The efficiency-thoroughness trade-off (ETTO) theory advanced by Professor Erik Hollnagel reminds us that safety is managed within a wider economic context. Despite the claims of airline CEOs that safety is their ‘number one priority’, when management decisions are made safety is one of several considerations.
We cannot identify every ‘failure-path’. According to Professor Charles Perrow, the interactive complexity, close coupling and opacity of complex machines like aircraft mean that failure is always a possibility. Back-up systems make things worse by adding complexity. Academic Geoffrey McIntyre says: “Redundancy often causes accidents: it increases interactive complexity and opaqueness, and encourages risk-taking”. Viewed through the lens of Professor Perrow’s normal accident theory (NAT), complex activities like oil and gas production, nuclear power generation, manufacturing, construction, sea, rail and air transportation are accident-prone. If we accept Perrow’s NAT diagnosis, a zero accident rate is an impossibility. When it comes to safety, there is a disjuncture between expectation and reality. People expect 100% protection. When a disaster reminds us that 100% protection is beyond our reach, we feel betrayed. Some lash out.
As to the frustration at our inability to find MH370, expectations are too high. We expect technology to solve every problem – a reflection first of saturation advertising for mobiles, lap-tops, the Internet and other ephemera, and secondly of the proselytising of high-technology luminaries like Bill Gates, Steve Jobs, Mark Zuckerberg and Jack Dorsey. If we look at the world through the prism of ‘technological exuberance’ we are going to be disappointed. Lap-tops, ‘apps’, smart phones, social networking sites and viral messaging won’t solve the world’s problems. Ignore the hype. Technology is fallible. Connectivity is circumscribed. Radars and satellites cannot see into every corner. Not every event can be explained. Not every broken aircraft can be found. The world is a hostile place. We must accept that fact.