رویکرد AHP برای تحلیل عوامل بشری در حوادث ناشی از یخ زدگی هواپیما

The reasons that icing of aircraft leads to an accident are diverse. Ensuring the aircraft to take off clearly is the important factor of giving support to flying safety. Human factor is one of the important factors which have caused the accidents. In this paper, because of the complexity and uncertainty of human factors, we introduce Analytical Hierarchy Process (AHP) to create weight model of human factors by analyzing and deciding importance of all kinds of human factors. Based on this basis, further study on assessment of human factors in aircraft icing accidents is developed, and the arrangement in importance order of human factors in aircraft icing has been given according to the given weight distribution of human factors. This paper provides reliable basis for equipment improvement and personnel management.

In winter, the ice, snow or frost will be found on the surface of aircraft and they will destroy the well aerodynamic characteristics of the surface of aircraft, which is injurious to flight safety. The aircraft which has been contaminated by the ice, snow or frost is not airworthy and must be treated with deicing and anti-icing. The FAA’s records of freezing between 2004 and 2005 show that if the icing thickness of the leading edge of aircraft wings, the rate of climb will decrease by 500 ft/min and the cruising speed will decrease by 40 km/h[11]. For some models, the safe flight pre-sta ll warmer will even likely be out of order. Therefore the icing of aircraft is the important facto of flying safety. In 2003, the research on the 26 accidents and the unsafe occurrences relating to icing indicates that 15 of them happened in the flying course (approaching and landing included), 10 of them happened because of incomplete de-icing or icing before taking off, and 1 of them has not been introduced in details[11]. In general, the period of the aircrafticing could be divided into two forms: ground maintaining period and icing during flight. However the final causes why the aircraft ices or the aircraft takes off with icing on surface are intricate, because they are affected by two forms together and can’t be attributed to one form. For example, the accident took place when one Douglas DC-9-140 was taking off in the American state of Colorado on Nov. 15, 1987 and that claimed hundreds of lives. On 10 Mar. 2003 , one Fokker F28-1000 crashed and was cut into three on Ontario, Canada when it was taking off and there were 69 passengers of whom 24 were killed. The two accidents were credited to the aircrafticing and both causes of 2 aircrafts’ icing included 2 forms: the secondary deicing before the aircraft (ground maintaining period) took off was neglected and the captain didn’t turn on the ice removing system[6]. So we can know that the reasons that the aircraft freezes are diverse and commonly have to do with operators. But because the human error has characteristics of uncertainty and difficulty of being quantized, the reasons which are included haven’t been analyzed concretely. The AHP is a kind of method by which the complex problem that is difficult to be quantized is converted into a series of simple problems that is easy to be quantized by downward depth profile analysis.This method is very commonly applied to the ana lyzing and evaluating problems of complex system [2] . Based on consulting the relevant literature, taking a dvantage of characteristics of AHP, which is suitable to Multi-Criteria and multiple- objective decision analysis into complex problems, this paper analyzed the human factors of the aircraft icing and on this analysis base that made clear the included factors and interrelation of these factors, then gave the weights of all kinds. Consequently, we can pointedly pay enough attention to the human factors which might happen in future to avoid the future tragedies.

1) To obtain the judgment matrix from the historical data or the experts’ assessment of all the affecting factors is the key of AHP, because whether the judgment matrix is correct or not can decide whether the check of consistency can pass the test or not. With the complexity of aviation incidents, it is very hard to analyze them, especially when they are related to the operators’ psychology and physiology which is very difficult to be quantized. However, we can solve this problem if we introduce the AHP to quantize all factors by the judging matrix. (2) The evaluation process is straightforward if we analyze the human factors by AHP. On the condition that the judgment matrix meets the consistency condition requirement, we can rationally assessthe affecting factors and get the priority order of all the factors’ influence on the final incidents. So the decision-makers and managers can clearly find the aspects needing to be improved and existing hidden danger. They may also shoot the arrow at the target when they seek for method and approach of reducing the aircraft accident.(3) In the future application, we can adjust the index of chart II to find its feet according to the specific airport, the specific Air Line and the new social factors.(4) To sum up the above arguments, because AHP has characteristics of reliable conclusion, practicability and precision, we can apply AHP into the analysis of human factors in aircraft accidents as a kind of convenient and effective evaluation method. Moreover, allow for complexity and diversity of human factors, the analysis of human factors should not be confined to one method, but multiple approaches should be resorted to. Thus we can assess the an alysis of accidents rationally and effectively.