A runway disaster just waiting to happen again

PUBLISHED : Sunday, 14 December, 2008, 12:00am
UPDATED : Sunday, 14 December, 2008, 12:00am

It has been called the 'crash of the century'. In heavy fog on a March afternoon in the Spanish island of Tenerife, a packed KLM Boeing 747 roared towards its takeoff, fatally oblivious of a Pan Am jumbo jet taxiing in its path.

A split second before impact, the fog cleared enough for both pilots to see the horror awaiting them. The KLM captain desperately tried to lift his plane off the ground, dragging his tail along the runway before shearing the fuselage of the Pan Am jet apart, and ripping an engine off the underside of one of his own wings.

In the inferno that followed, 583 crew and passengers from both planes perished, making it the worst accident in aviation history. Three decades on, the 1977 crash remains the single most deadly airline disaster - a tragedy on a scale that with today's advanced technology and sophisticated airport systems could surely never happen again. Or could it?

It is a nagging question that was raised again by a comparatively trivial incident on a morning in September at Hong Kong International Airport when a South Korea-bound Boeing 737 with 122 passengers on board tried to take off down a taxiway rather than a runway.

In this case, there was no packed jumbo jet lying in wait, and the frantic radio calls of an air-traffic controller made the Hong Kong Airlines captain realise his blunder in time to abort takeoff. But it provided a stark reminder of how easy it still is for a disoriented pilot to make a potentially fatal wrong turn. Many pilots and aviation experts worldwide agree that while sophisticated new cockpit systems have led to huge advances in the avoidance of mid-air collisions and crashes into the ground in poor visibility, too little has been done in terms of technology to prevent a repeat of the tragedy of Tenerife.

In the US, a report found last year that runway incursions - where planes mistakenly stray onto active runways - take place at the rate of almost one a day. The risk of an accident killing hundreds of people at an airport is 'real and growing larger', the report warned.

Many pilots and experts believe the bewildering sprawl of taxiways and runways that spider out across today's constantly expanding international airports are an accident waiting to happen.

So who was to blame for the Hong Kong Airlines incident of September 13? A Civil Aviation Department (CAD) spokeswoman told the Sunday Morning Post a thorough investigation had found the incident was caused partly by a 'temporary loss of situation awareness on the part of the flight crew concerned prior to the commencement of the takeoff manoeuvres'.

The plane's Indonesian captain and first officer appear to have shouldered most of the blame, having been immediately suspended and subsequently dismissed. From the beginning of the CAD investigation, the airline appeared to be prepared to allow the pilot and co-pilot to take full responsibility.

A management source at Hong Kong Airlines pointed out that the apron markings and lighting at Chek Lap Kok were so clear, a pilot would have to be 'really, really stupid' to attempt to take off from a taxiway.

Runways at the airport are clearly distinguished by red lights at the side and white centre-line markings, while taxiways have green lights running down each side and no centre line, the source said.

'The runway in Hong Kong is super-duper,' he said. 'It is a very colourful runway. You can see the lights very clearly, especially at 4 o'clock in the morning. So you have to be really, really stupid to try to take off from a taxiway with green lights.'

The view that this was a case of pilot error was widely shared among the pilot community, which saw it as a consequence of the airline sacking experienced expatriate pilots and replacing them with less competent fliers.

'As a pilot, I have to say it would be very difficult to mistake a taxiway for a runway in Hong Kong. The taxiway doesn't look anything like a runway,' said one Cathay Pacific pilot. 'I suspect the problem was that the pilots involved in this incident weren't used to flying into major international airports. The taxiways at Chek Lap Kok are bigger than most runways at airports around the region.'

The CAD's findings were not so clear cut, however. Apart from apportioning some blame to the flight crew and recommending improved crew training and procedures, the investigation concluded that taxiway lighting and ground-marking systems at Chek Lap Kok needed to be improved.

Lighting and ground markings at the airport are up to international standard, the spokeswoman insisted, but she added: 'In light of the current incident and in order to assist pilots in enhancing the situation awareness when taxiing an aircraft to the runway, the CAD will ... discuss with the Airport Authority measures to further step up the visual guidance given to pilots.'

The report recommends changes to 'some of the lighting and ground-marking systems at the HKIA focusing on helping the pilots to maintain their orientation'. The findings were believed to centre on the southwest corner of the apron, where the attempted takeoff took place.

The findings are significant because there have been two previous incidents involving attempted takeoffs from taxiways at the airport - in June 2003 and May last year. Some improvements were made to lighting and signage after the latter.

Alex Au, a spokesman for Hong Kong Airlines, said last week the recommendations arising from the CAD investigation proved that what happened was part of a broader problem.

'It isn't just us. Other people have fallen into this trap,' he said.

'There are areas in the airport where it is very dark and where there is a lot of lighting, which can be confusing. The report addresses the issue of the southern corner of the airport and it has good recommendations.'

He added: 'We accept the findings. This has been a lesson learnt. There are particular parts of the airport where you have to be careful, and we will reinforce our training and other aspects of our procedures. The report is a fair report and action needs to be taken by the airline and by the Airport Authority.'

A senior Hong Kong-based captain said the incident illustrated a general failure of the airline industry to develop sufficient safeguards against ground collisions. Some airports, particularly those in major US cities, were a 'dog's dinner' and far harder to navigate than Hong Kong's, he argued.

'The fact that things like this are still occurring, even on one of the best airports in the world, shows there is a problem that needs addressing by the aviation community,' the captain said.

'The technology we have today isn't too different from what we had at the time of the Tenerife disaster. Nothing major has been done to prevent an accident of that kind happening again.

'We didn't use the accident as a wake-up call to develop the technology to prevent it happening again ... We should do more.'

A study of runway incursions by the Airline Pilots' Association International last year found that on average over the past five years in the US alone, there were 325 incidents annually of planes straying onto active runways - almost one a day.

Since the Tenerife disaster, there have been five fatal accidents involving runway incursions in the US, including one in Los Angeles in 1991 that killed 34 people. As well as the fatal accidents, there have been a number of near misses.

While traffic alert and collision avoidance systems have cut the risk of mid-air collisions and ground proximity warning systems have cut the incidence of planes flying into the ground or an obstacle, no such technology has yet been introduced to prevent the risk of planes straying onto active runways, the report points out.

Ground radars, not in use at the time of the Tenerife crash, and improved training have helped to contain the risk to some degree, but the growth of airports and air traffic has increased the likelihood of a major accident to a far greater degree.

The report called for the introduction of on-board moving map displays, a technological measure which the association estimated would help cut runway incursions by 95 per cent, along with better airport markings and runway status lights and takeoff hold lights.

'The risk of a runway incursion event that could kill hundreds of people in a single accident is real and growing larger,' the report concluded. 'The current level of risk is unacceptable. Strong and immediate mitigations need to be implemented.'

At Hong Kong Airlines, meanwhile, steps have already been taken to avoid a repeat of September's incident, according to the management source. Every pilot at the airline is now being given 10 minutes of additional training in a simulator to ensure they can safely navigate their way from taxiways to runways at Chek Lap Kok, the source said.

'We have also given everybody a map of the airport and told them, 'Go home and study it before you sleep - that's where the runway is, so remember it',' he said. 'This is not to be taken lightly. Pilots shouldn't take off unless they are absolutely sure they are on the runway.'