David Learmount/LONDON
In the first six months of 2000, fewer airline accidents occurred than in the same period last year - but the tragic irony is that the number of fatalities has more than doubled. Meanwhile a sense of deja vu clings to several serious accidents in 2000, either in terms of how the crash happened or in the investigation and its repercussions.
Airline accidents killed 552 people in 19 fatal crashes in the first half of this year, compared with 178 deaths in 22 fatal accidents for the same period in 1999. The statistical average for the first six months of each year over the past decade is 445 fatalities and 20 accidents, but traffic has increased by more than 50% since 1990, so figures for the year 2000 so far do not show an increasing fatal accident or fatality rate.
The worst single accident so far this year has been the Kenya Airways Airbus A310 crash in which 169 people died. Witnesses reported that the aircraft, taking off from Abidjan, Ivory Coast, made a long take-off run, failed to gain height, then crashed into the sea about 2km (1nm) offshore. Apart from the casualties, the most worrying aspect about this accident is that, more than a month after the two flight recorders were recovered from the wreckage, the manufacturer declared that it had been given no information, and therefore could not determine whether any operating or engineering advice should be passed to A310 operators.
Eventually, the recorders were given to the Transportation Safety Board of Canada for downloading, and now the French Bureau Enquête-Accidents has been invited to assist the Ivory Coast authorities in the investigation. In May, the Kenyan parliament received details from a normally confidential Airbus accident information telex to its A300/A310 series operators, which contained the little that Airbus knew, gleaned from an investigation committee meeting which it had been invited to attend.
The parliamentary answer revealed that the flight data recorder (FDR) contained no information, but the cockpit voice recorder (CVR) information was high quality. No reason was ventured as to why the FDR carried no data.
A basic summary of information presented to the Kenyan parliament included:
• all the crew normal checklist items and responses were recorded on the CVR;
• the take-off roll, rotation, and the call for gear up were normal;
• less than 2s after the gear up call an aural stall warning sounded. This continued during the descent until about 100ft (30m) above thesurface;
• the engine sound, after analysis, was found consistent with the thrust settings selected;
• the accident investigation committee made no recommendations for A310 operators.
The delay in downloading the flight recorders, and the paucity of information made available to the industry by the Ivory Coast authorities is not unusual for investigations in many countries, despite the fact that airlines may, as a result, be operating without safety-critical information which they should have.
Maintenance quality
In the USA, the Alaska Airlines Boeing MD-80 loss of control accident raised such serious concerns about maintenance quality control that the Federal Aviation Administration is radically changing the method by which it applies its safety oversight checks in the future.
Although the inquiry has yet to report its findings, investigations have centred on the fact that the horizontal stabiliser appears to have moved uncommanded to a full nose-down pitch position. Recovered wreckage revealed that the stabiliser jackscrew had been stripped of its thread and, although the impact could have done this, it may also have been the crash cause.
Consequently, Alaska's maintenance procedures were put under the microscope, and so many deficiencies were found that the FAA threatened to suspend Alaska's licence to carry out its own heavy maintenance unless, within a week, it presented a completely revised maintenance quality control system. Alaska beat the FAA deadline with an acceptable plan, and the threat was withdrawn.
The FAA explains that the investigation revealed as many faults with its own traditional inspection system as with Alaska's quality control, a development reminiscent of the situation which came to light during investigation into the ValuJet McDonnell Douglas DC-9 accident in May 1996, in which the FAA's inspection system was condemned by the US National Transportation Safety Board. After the accident, the ValuJet maintenance arrangements, mainly third party, were found to be so badly supervised by the airline that the carrier's operations were shut down.
This time, however, the FAA has decided that it must change itself. Airline inspection has traditionally been carried out using a "bottom up" technique, the FAA explains, by checking a proportion of aircraft in the hangar and those which have come out of maintenance. Now the FAA proposes to use a "top down" method, an audit of the airline's whole engineering quality control system, which is what it has done at Alaska. Now the agency is setting up maintenance quality control audits of all the US carriers, starting with the majors, with the intention of using this system in the long term.
Non-precision danger
A June Air Philippines Boeing 737-200 accident was almost certainly a case of controlled flight into terrain (CFIT), and the approach on which it happened conformed to the classic pattern identified by the Flight Safety Foundation's CFIT working group. The aircraft had gone around again from a precision approach because the runway was momentarily obstructed, and the crew elected to carry out a non-precision VOR/DME letdown toward the reciprocal runway for their second approach. During the non-precision approach, the aircraft hit a low hill in poor visibility.
This year two countries have made additional positive moves to reduce CFIT accidents which have, for many years, caused more fatalities than any other accident category. The US FAA and the UK Civil Aviation Authority have become the first state aviation authorities to mandate terrain awareness warning systems (TAWS) for use even in small regional airliners. According to a CAA calculation for its TAWS cost-benefit analysis, if the equipment were fitted worldwide it would save "one major accident a year globally".
Fitment in the USA and UK will have to be complete by 2005, and much earlier for larger airlines and new aircraft. Carriers like American Airlines and British Airways began fitting the system in advance of the new regulation. User airlines report favourably on its effectiveness (Flight International, 18-24 July), and the European Joint Aviation Authorities say they are preparing regulations to make TAWS a required standard throughout the continent.
The pilots of the Emery Airlines McDonnell Douglas DC-8 freighter which crashed in February reported a centre of gravity (CG) problem before they lost control of their aircraft and died in the ensuing crash. In August 1997 another US freight carrier, Fine Air, suffered a fatal accident to one of its DC-8s because of CG problems. The load shifted during take-off and the pilots lost control.
Also this year the UK Air Accident Investigation Branch has published a report on a January 1999 Channel Express Fokker F27 freighter accident which killed both pilots. The loading was badly managed, putting the aircraft CG well aft of limits. When the pilots selected full flap on final approach the aircraft pitched up uncontrollably and it stalled and crashed.
The report was an indictment of the loading itself, of the system for training loaders and handling agents, of crew training in cargo management, and finally of the captain for signing the load sheet without an adequate check of the cargo bay. Perhaps the latter was the result of the poor crew training alludes to in the report.
How many more pilots will have to lose their lives to poor loading discipline before airlines - even in the USA and the UK which have above average safety oversight standards - take the cargo problem seriously?
Source: Flight International
