Flight Safety & Human Factor in Occurrences
Flight Safety & Human Factor in Occurrences
By Jamal Barki
Type of occurrences
Many accidents involve a sequence of events. Each event may have been followed by further events not reported. For example, an aircraft which sustained an engine failure may have then been involved in a hard landing. The most frequent first event leading to fatal accidents was loss of control. The next most frequent first event was collision with terrain, control unknown where the investigation could not determine whether the pilot was in full control of the aircraft. Controlled impact with terrain refers to accidents in which the aircraft struck terrain while apparently under the control of the pilot. Such accidents typically occur in conditions of reduced visibility. Collided with object (not wires) includes cases in which an aircraft collided with trees, buildings or other obstructions. Collision with power lines is treated separately under wire strike.
Broad accident factors
Seventy-two per cent of the accidents were judged to involve pilot factors. Weather was a factor in 17% of the accidents. Other personnel contributed to 12% of the accidents. Other personnel refers to people other than the pilot of the aircraft, and includes air traffic controllers, other flight crew and maintenance workers. Note that accidents may be assigned multiple factors.
Pilot factors
The most commonly assigned factor was poor judgement. Other common factors were in-flight decisions or planning and attempted operation beyond experience or ability. These results are consistent with the general worldwide finding that inadequate decision making contributes to a large proportion of accidents in general aviation and airline operations. Examples of inadequate decision making or poor judgement are knowingly continuing a flight into adverse weather, engaging in unauthorised low flying and continuing a flight with a known low fuel state. Medical factors were relatively rare. Main factors included mismanagement of fuel system and selected unsuitable area for landing or takeoff.
Further detail on human factors terminology
Poor judgement
For many years it was assumed that good judgement was an inevitable by-product of flying experience. However, the data that BASI has accumulated indicates that errors of judgement are made by experienced and less-experienced pilots alike. Airlines around the world recognised in the 1970s that even experienced crews could make serious errors of judgement. For example in 1979, the crew of a United Airlines DC8 were distracted for so long by a landing gear problem that they eventually ran out of fuel. Many major airlines have now introduced crew resource management (CRM) training to ensure that flight crew apply principles of judgement and teamwork. However, for general aviation and regional airline operations, pilot judgement continues to be a significant accident factor. In the 1980s, the Australian Department of Aviation and equivalent bodies in the USA and Canada sponsored the development of judgement training courses for pilots. The results indicated a significant reduction in aircrew errors. In 1987, the US Federal Aviation Administration (FAA) released a series of manuals oriented to the decision-making needs of general aviation pilots. The FAA later released an advisory circular on the subject of aeronautical decision making.
Diverted attention
Pilots may divert their attention from the operation of the aircraft for a variety of reasons. Diverted attention is particularly likely when the pilot is under time pressure or stress. For example, a minor abnormality such as a landing gear warning may distract a pilot from other aspects of the flight. In the following example, an experienced pilot collided with power lines which he was aware of. The investigators believed that his attention had been distracted. The single-engine Cessna was being flown by the owner on a flying holiday with three friends. The pilot had experienced navigation difficulties during the holiday and as a result, the CAA required the pilot to undertake local navigation training before continuing the flight. Following the training, the pilot departed on the next leg of the flight with 70 minutes of daylight remaining. The flight was planned to take 55 minutes. The pilot was apparently unable to locate the aerodrome and decided to land on a curved gravel road at an open cut mine about 40 km from the planned destination. The pilot decided to camp the night near the aircraft. The next morning the aircraft was observed by a number of witnesses to attempt to take off from the gravel road in the opposite direction to that used for landing. This had involved passing through an 18-m wide steel frame which spanned the roadway and then negotiating a curve of about 50. After a take-off roll of about 500 m, the aircraft became airborne for a brief distance before the landing gear struck a low mound of rocks. The aircraft then descended steeply before impacting a step of the open-cut mine about 200 ft below the level of the roadway. The pilot and two passengers were killed; one passenger survived the accident with serious injuries. The pilot was 57 years old and had accumulated 500 hours of flying experience.
In-flight decisions or planning
Problems with in flight decisions or planning include situations where a pilot elects to continue a flight with a known deficiency continues a visual flight into adverse weather or makes a poorly planned approach to an airfield. The following example illustrates how inadequate in-flight decisions or planning can lead to an accident.
Inadequate pre-flight preparation or planning
In many cases, the origins of the accident began well before the aircraft left the ground. Prefight preparation or planning includes the pre-flight check of the aircraft, flight planning and weather briefing. The fuel gauges of light aircraft can be unreliable and pilots are expected to visually check the amount of fuel in the tanks before flight. The following example illustrates how a minor error during this pre-flight inspection apparently led to an in-flight fuel loss. The pilot had been conducting superphosphate spreading operations in the area two days prior to the accident and had completed approximately 60 trips during that operation. On the morning of the accident, he had just completed the sixth load and was returning to land at the strip when the outboard section of the right wing struck power lines. The right wing was torn from its attachment points and separated from the aircraft. The aircraft then impacted the ground in a steep nose-down attitude and came to rest 169 m from the power lines. The pilot, who had accumulated nearly 24,000 hours flying experience, was fatally injured in the accident. It is probable that the pilot forgot about the presence of the power lines. The short charter flight in a light single-engine aircraft had been arranged to transport three passengers to another aerodrome where they were to connect with a scheduled flight. The passengers had less than 15 minutes to make the connection. After a normal takeoff, the aircraft was seen to make an abrupt right turn at about 250 ft above the ground. The aircraft was last seen descending towards the ground in a 45 nose-down attitude. All four occupants were killed in the subsequent impact. The behaviour of the aircraft in the moments preceding the impact was consistent with a stall leading to loss of control. The investigators considered that the pilot was in a hurry to depart and had not climbed the aircraft to a safe height before making a turn downwind in turbulent wind conditions and had not maintained sufficient airspeed for continued flight under the prevailing circumstances.
Conclusions
In conclusion, the largest proportion (36%) of fatal aircraft accidents occurred on private/ business flights. The three most frequent first events in accidents were loss of control, collision with terrain (control unknown) and wire strike. Most accidents had more than one contributing factor, although pilot factors were involved in over 70% of fatal accidents. The most common pilot factors related to poor judgement and decision making. Bureau of Air Safety Investigation (BASI) experience has shown that errors of judgement can be made by experienced and inexperienced pilots. This report deals mainly with the human factors which relate to pilots. In recent years however, BASI has recognised that while pilot factors are of great importance, accidents frequently have their origins in the aviation system as a whole. Organisational factors such as training, supervision, regulation, commercial pressures and licensing are involved in a significant proportion of accidents. The investigation of these organisational or systemic factors now forms the basis of much of BASI's investigation and research effort.
Flight Safety & Human Factor in Occurrences
By: Jamal Barki
Know How Site Safety Plans Can Help Your Financial Stability Shopping for electronics Low Frequency Rfid Tags For Various Lf Rfid Applications Shopping In Your Pjs: Electronics Investment casters using ERP/MRP software provides traceability for safety critical components Strong electromagnetic interference will also cause damage to laptop battery Lithium ion Battery Material Properties and The Battery Safety Medicare Supplement Insurance For Your Wife's Safety Knowing About Issues Of Health, Safety And Also Security In Demolition China Electronics The Black Box - Safety At Sea Air-con For Less Heat And Humidity - Your Electronics Are Going To Work Better Investment Safety With Cd Accounts