Air Crash Investigation. Basic methods.
Helpful information
Air Crash Investigation. Basic methods.

Air Crash Investigation. Methods. Results.


Air Crash investigation is an important step to understanding rethinking of accidents related to aircraft and efforts to prevent or not prevent the recurrence of similar incidents in the future.

Air Crash Investigation. Basic methods.

NTSB (National Transportation Safety Board), usually acts as the primary organization investigating the incident in its area of ​​responsibility. However, by a decision of the United States Attorney General, these credentials can be transferred to other organizations, in cases where the prosecutor believes that the crash is related to the intentional offense.

However, even in such cases, the NTSB technically provides and provides information support for the investigation. This happened the last time during the investigation into the events 11 September 2001, when the investigation process was handed over to the United States Department of Justice.

Air Crash Investigation. Basic methods.


The investigation of large-scale incidents in the United States usually begins with the creation of "rapid response team", which consists of experts in areas directly or indirectly related to the incident. Next, the number of companies and organizations that need to engage in the investigation. Council may appoint on relevant issues a public hearing.

At the end of the crash investigation process, an official final report is published and safety recommendations are provided to the aviation industry as necessary. The Council has no legal authority to implement or implement its recommendations. This part of the safety process is handled by the United States Federal Aviation Administration (FAA), regional and federal transportation regulators, and transportation companies.

Air Crash Investigation. Basic methods.


NTSB to investigate all incidents occurring in civil aviation has the highest priority in the United States. FAA also always involved in the investigation, but it is the main NTSB investigative body. In some cases, lack of resources forces the NTSB contact the FAA with a request for the collection of facts, evidence and information at the scene, and then your report is based on data that have been collected.

In some cases, the NTSB also helps in the investigation aviaktastrof happening outside of the United States of America. This usually happens when the incident happened to the aircraft that has registered in the United States of America or the American owners, with the aircraft in a foreign airspace if it installed components manufactured in the United States of America.

Air Crash Investigation. Basic methods.


There are at least 12 basic methods that use investigative NTSB type Commission under Air Crash investigation:

1.Poisk the four corners of the plane (for the determination of: broke up in the air or on impact with the ground);

2.Poisk voice and flight recorders. Listening;

3.Proverka radio communication with the controller;

4.Svodka ATIS (thunderstorms, hail, microbursts);

5.Poisk and assembly of fragments (all systems);

6.Ispytanie similar models in similar conditions

7.Ispytaniya in the simulator;

8.Issledovanie personal affairs pilots psychological factors

9.Proverka passengers tickets and cargo waybills (the probability of a terrorist attack);

10.Opros survivors, eyewitnesses;

11.Patalogoanatomiya corpses;

12.Prosmotr video crash.




The investigation of air accidents in a number of countries engaged in state organizations. The US has a National Committee for Transportation Safety (NTSB), which covers all kinds of transport. The NTSB has Office Safety, consisting of two departments to investigate air accidents and one of analysis and assistance. All reports and recommendations given by the operating organizations and companies, are made public. as there is a special decision of the Congress.

In England, the investigation of flight accidents civil helicopters conducting Committee to investigate flight accidents at the Ministry of Aviation. But the investigation of flight accidents are also involved in the company and the Aviation Institute. The overall coordination of the investigation of air accidents carries the Royal Aeronautical Institute (RAE) at Farnborough.

circuit investigate accidents

In Canada, the investigation of civil aviation flight accidents leading department RL.P composed of two divisions: the scientific and technological laboratories and offices operational statistics and planning. These units are conducting an investigation of flight accidents occurring on the lines. In addition, there are six regional offices

various parts of the country, the rest are investigating the accident flight. Airlines in Canada are also paying a lot of attention to safety and investigation of flight accidents. For example, the airline "Air Canada" has a group of 6 people., Which deals with flight safety. Sometimes to investigate flight accidents, a special commission appointed by the Ministry of Civil Aviation with the involvement of representatives of aviation companies and other organizations.

The main objectives, which are pursued in the investigation, determine the root causes of flight accidents: "What happened?", "Why happened?" Rather than "who is to blame?", "Who punished?" - To obtain information for the necessary decisions to prevent similar flight incident. One of the important tasks is to identify all the causes contributing to flight accidents as a flight accident is a consequence of many factors.

In the United States, the flight accident investigation process is led by the Aviation Safety Research Administration, which is responsible for all safety work. It investigates 18% of flight accidents. Teletype communication provides the center with constant information about all flight accidents; it receives preliminary information 6 hours after any flight accident has occurred. A Flight Accident Investigation Officer is appointed for operational management. He creates working groups, as well as organizes, conducts and monitors the investigation of a flight accident, collects factual information, draws up reports on the results of the investigation. In the remaining 82% of cases, flight accidents are investigated by air bases and local specialists.

Each airline has a detailed action plan in case of flight accidents with functional responsibilities of each expert, with an indication of what and in what form the report, and so on. D. Plans provides sohranenie- tape films of all records of communication, the work of the material, maintenance documentation and repair of helicopters and analysis of samples of fuels and lubricants from a warehouse and a filling means, and so on. d.

Initial measures in place flight accident receives chief of the nearest airport. These include: the challenge of health workers to provide assistance and rescue people; defense rests helicopter fire, protection from damage and displacement; preparation of the necessary information about the flight accident investigation to the Office of Aviation Safety; preserving traces of the incident on. land and local objects; registration information collected through witnesses and eyewitnesses.

The investigation of flight accidents lasts from several days to several months, the restriction on flight operations introduced only for the time necessary for the investigation of the wreckage at the site of the accident flight.

To the persons participating in the investigation, the following requirements are required: high qualification in this field, analytical mindset, interest in the case, necessary diligence, patience. Qualification of specialists (pilot or engineer) should take into account the duration of the operational experience, participation in air traffic control, etc. All groups work according to a plan that is known to every specialist in advance. The group is provided with equipment that makes it possible to: investigate the debris and the place where the helicopter strikes the ground; Crocheting; Photographing, with the apparatus provided by all members of the group; Use of television and optical equipment, video recording of the process of investigating a flight accident.

To investigate a flight accident with a small helicopter, long-used in the units, a group of 4-5 people is appointed. From the local airbase. The composition of this group at all air bases is determined in advance by management. If the helicopter is new, or the flight incident is of a heavy nature, then a special commission consisting of several groups of specialists is appointed. Each group is headed by a highly qualified specialist. The group should include experts of the operating organization, representatives of manufacturers, representatives of flight crews, etc.

The group is engaged in clarifying the mode of operation of flight crew operations, flight dynamics and flight path before the accident flight. This group defines the flight planning, action dispatching service, mass centering data, weather conditions, communications, air traffic control, status and operation of navigational aids, these intermediate landings, refueling, oil, liquids and gases, operating experience of flight, ground services , the last checks of the crew and the volume of checks, other details of the flight crew.

Group work with witnesses to find out everything that concerns flight accidents of all witnesses, and taken a written explanation with the signatures. Group flight recorders provides search, retention, reading, transcripts devices.

Group study explores the glider airframe design and management. The objectives of this group - to detect and identify the wreckage of the helicopter, to put their position on the scheme.

Drawing up a report on the accident

To improve the efficiency and completeness of the investigation of serious air accidents in some countries, such as Canada, create graphics investigate flight accidents.

This program provides a systematic study of all the circumstances of the accident flight, making the organization and eliminates the chance of misunderstanding and errors in the work of the commission, which operates in a challenging environment.

Documentation component in the investigation of air accidents, different in form and content in a variety of countries. In some countries, a standard form which facilitates the machining data on flight

accidents, reducing the time to complete the documentation and virtually guarantee the completeness of the collected material. Group prepares documentation: information about the flight accident report; factual information obtained during the investigation; reports, reports of groups that are part of the Commission; a report on the causes of the accident flight, the conclusions of which reasoned evidence and logically justified.

Applied to the report, all working documents to the superior court could review the validity of the conclusions of the Commission.

The working documents include: the scheme of distribution of debris; Picture of the place of the flight incident; Recording of radio traffic (the results of their processing); Recorders on flight parameters; Calculations of mass and alignment; Testimony of witnesses; Air traffic control personnel; Reports reflecting the state of the helicopter's design, its systems and units; Data on laboratory tests and studies; Report on the work on technical operation and repair; List of uncommitted technical instructions; Medical report on each affected person; Report on skydiving if the crew performed a test flight; Report on the damage from the flight.

Report flight accident consists of five parts: a detailed description of the accident flight; damage as a result of a helicopter flight accident; a detailed description of the facts relating to a flight accident (in chronological order of presentation of all the factors contributing to the emergence of a flight accident); a detailed description of the causes and other factors contributed to the accident flight; recommendations to prevent new similar flight accidents.

If the Commission were groups, each of which is a report with all the spent working documents. The report of the group must contain: an impartial presentation of the facts relating to this flight accidents, analysis and logical conclusions based on the results of investigations.

The Board receives reports of all groups and uses them in the preparation of the report on the investigation of the accident flight. It must also submit a report on the dissenting members of the commission with the recommendations adopted by the majority of the committee members, with its conclusions and recommendations.

Classification of air accidents is different in different countries, but there are also international classifications. The following is an abbreviated, truncated, without the lower ranks, the classification of flight accidents, recommended by ICAO.

It is recommended to classify the incident flight, depending on: the type of flight; phases of flight; the type of accident; causes of the accident flight.

The following types of operations: on the international road; on the inner track; shuttle; non-scheduled; to perform work in the air; for business operations; training; control and testing; Private helicopter flights; other flights.

Phase of flight in which the circumstances arise, leading to a flight accident, the following:

static (between planting and the start of passenger traffic between the helicopter and final stop at the end of the flight and the landing of all passengers); during taxiing; during take-off; while en route; during landing.

The types of incidents indicate the circumstances under which they occur. These include: loss of controllability in flight, on land or in water; Touching the ground with the ends of main rotor blades, gondola or float; Destruction of the chassis; Rough landing with a lowered nose, or hooding; Landing with a shortage to the runway, landing on the edge or beyond, rolling out beyond the runway; Collision with the surface of the earth, water, with objects or birds; Destruction of the glider on the ground or in flight; Separation of aggregates; A fire or explosion on the ground, in flight; Planting for precaution and forced landing; Accidents on the ground associated with the air jet of aircraft engines; Injuring people with propellers; Injury to people in flight; Other cases; Unidentified type of incident.

Causes of air accidents can be linked to human error on the board and on the ground:

flight accidents, associated with the destruction of the structure of the helicopter are due to the destruction of nodes structure of (mechanical reasons (excludes cases where a failed engine, propellers, systems and equipment), the destruction of the chassis damage or engine failure, destruction of aircraft or the rotor caused by the failure or defects in different systems;

flight incidents connected with failures in devices and radio equipment, are divided into instruments to cause a denial of control engines, flight and navigation instruments, navigation equipment, radio communication equipment, lighting equipment.

The procedure for investigating flight incidents provides the following order: debris, their location and traces on the terrain (trees, rocks, bushes, etc.), the bodies and their remains remain in their original position until the photographing is made, the necessary circuits are drawn up And description; The presence of all the parts at the place of the fall is checked, and in the absence of at least one detail, all the necessary measures are taken to find it; Material evidence is used to conduct research; Before sending physical evidence, they are carefully packed; Before extracting the parts, a mandatory photographing of their locations in a pile of debris is made, a label with the necessary information is attached.

In investigations, two methods are used: deductive (version analysis) and the reproduction of possible conditions of a flight accident. Correctly determine the destruction in the air can be the nature of the scatter of debris. If there was no destruction in the air, then several more plausible versions are developed and their verification is conducted. Malovoditelnye versions are not considered. The investigator should accurately and accurately record all the data, collect only reliable facts. At the same time, it is necessary to record all the facts, regardless of whether they are important or are not yet considered such. Systematically and exhaustively all facts are investigated; And circumstances without the influence and pressure of the authority of other specialists.

Each helicopter system is considered equally important, since without research it is impossible to determine in advance whether any of the systems are involved in the causes of the flight incident. Data on the investigation of one system can be used to prove the involvement of another system in a flight accident. First, the actual state of the debris is ascertained, fractures, discontinuities and unburned areas are checked. All these facts speak of local events, but in. Finally, they add and expand the overall picture of actual events. At this stage, do not expect any special information to not miss the other, more important.

Laboratory tests are not limited to standard tests. Every effort is made to perform tests that fully reproduce the operational capabilities of the elements in unusual conditions. The research takes the details together with the related elements, so. How often the causes of a defect are in conjugate elements. Particular attention is paid to the search for defects, which are the result of wear of parts, fatigue, structural, deficiencies, negligence during installation or operation. The most frequent cause of flight incidents is the failure of the power plant. Therefore, in the absence of actual data on the cause of the flight incident, it is recommended to consider the engine "guilty" until evidence of his "innocence" is established. If a subjective error is established, then the investigation does not stop. In this case, they are looking for why this subjective error of man (a poor design, disregard for the principles of engineering psychology, insufficient or unsatisfactory methods of exploitation) became possible, that is, they try to establish the circumstances that contribute to these errors.

During the investigation, a general inspection of the debris is made on the spot to clarify the picture of the circumstances of the flight accident. At the same time, they establish a point of initial impact, trace the path of the helicopter, searching for tags on the ground and local objects. Determine the possible trajectory of the helicopter, the angle and speed of landing, controllability and the presence of structural failure before the collision. The whole site is photographed with the general picture of the wreckage and their condition. Photographing is carried out from four directions. Photographs of individual sections and elements of structures, paying special attention to instruments, the position of control knobs in the cockpit, tuning radio stations, installing the autopilot, the position of the fuel valves, switches, the position of the control surfaces, the installation of trim tabs, suspicious breaks or deflections, the position of the propeller blades, the position of the engine control levers In the cockpit and on the engine itself, damage from the fire, traces on the ground in the fall, the position of the seats and the seat belts. Sometimes in the investigation of flight accidents, stereo shooting and aerial photography are used.

Charts the location of debris, goods, corpses and human beings, marks on the ground and points where photographed. Particular attention is drawn to the point of first contact with the ground, the length and depth of the slip traces, obstacles (trees, bushes, etc. D.), The position of the main fragments (fuselage), distance, direction, interposition of the main parts, the position of the other parts, the direction flight and wind.

The wreckage is searched all over the area. If it is large, then several search groups are created. The debris does not move from place to photographing and drawing up the circuit. The experience of recent investigations has shown that with a good search organization it is possible to collect up to 70% of the debris even in the case of a flying accident over the water surface, at depths up to 200 m. For the tests, details remain that have cast doubt on the quality of casting, heat treatment, compliance with specifications and ., E .; Parts that have structural and operational disadvantages; Pipelines, connecting control units, parts with insufficient fastening, subject to vibrations; Broken oil and fuel-wires; Assumed

Sometimes a special group is created to search for witnesses and record their required testimony. Usually, when working with witnesses, the interview is conducted in the form of an interview, while emphasizing the importance of testimony, but if they differ from the results of inspecting debris, then one must be very careful with the conclusions. From the air traffic control personnel, the air traffic controller windows service, operation and maintenance services take written testimony. Sometimes for demonstrators a demonstrative flight is made so that they can compare their impressions with the flight of a helicopter that has suffered an airplane accident.

The general principles for the defense of witness testimony are: to collect them as quickly as possible; Talk at the place where the witnesses were during the flight incident; To talk without strangers; To exclude conversations of witnesses with other persons before recording their testimony. It is necessary to hear all the witnesses without exception. The questioning of witnesses is carried out in two stages: to hear their story about everything that they saw, ask questions for clarification of individual clarifications. Record of testimony is conducted by a person specially trained for these purposes. Usually recorded: personal data, time and surveillance materials.

The last phase of the flight - this is the stage from the time when normal flight is terminated, until the inevitable flight accident becomes apparent.

Reproduction of it requires coordination between many groups, but mostly it is the group investigating the issues related to exploitation. An analytical method is being developed that makes it possible to determine the parameters of the flight trajectory and the velocity vector at the time when the helicopter is destroyed in the air. The method is based on solving the equations of motion of fragments taking into account the wind and gradient of atmospheric density. It is necessary to solve a system of second-order nonlinear differential equations. Calculations on a computer take a few minutes. For the initial data, only the distribution of debris on the ground and information on the state of the atmosphere are taken.

Widely used in the investigation of recording flight recorders. Their records are coordinated in time. At the first stage all data is read in the laboratory. At the second stage, the data of a senior accident investigation specialist is analyzed, which consults with aerodynamics specialists and a doctor. When necessary, a graph of the total energy of the helicopter is constructed to obtain information on engine power changes and to determine the position of the controls. The conclusions drawn from the data of the recorders are compared with the conclusions drawn from other sources; If they do not coincide, then the cause is determined.

Methods of reading and analyzing data from recorders are constantly being improved. Currently, methods are being developed for automatic reading and correction of data from recorders with subsequent automatic plotting of graphs and data analysis with the help of computing devices. It is possible to create a system in which the output of flight recorders after intermediate processing is fed to the simulator to reproduce the regimes that led to the molding event. Airborne dictaphones provide information for the investigation of flight incidents, as they record information that is not transmitted by the radio by radio on what is on board, what measures are taken to prevent and eliminate the emergency situation. In addition to talks between the crew members, the recorder also records other sounds: from switches, audible warning signals, engine noise, which is very necessary for the investigator of the flight incident. According to the spectral analysis of sounds recorded by the recorder, it is possible to determine the rotor speed of the turbine, compare these sounds with the standard spectrograms obtained for a helicopter of this type.

In the study of questions of technical operation of the most important are: the history of exploitation (plaque, the number of landings, and engines, systems and components of the helicopter) defects and corrective measures; implementation of improvements and work on the ballots; Careful adherence to the established system maintenance services operation, the definition of deviations and omissions; Poll technical and operating personnel on the methods of implementation and monitoring of works, inspections, and their volume.

In the study of the structure of the helicopter used the basic principle - as much as possible on the site of the accident flight to make the technical investigation, being careful not to damage the evidence. Individual parts are prepared and sent to special studies.

At the scene of the accident, it is necessary to determine where the damage occurred from the impact on the ground or it occurred in flight, and for this it is necessary to carefully inspect all the spots and particles on the debris. This is done before sending debris to the study. Careful examination of stains and scratches provides particularly important information when a flight accident occurred from a mid-air collision. Laboratory analysis of the spot gives an answer about its nature, and sometimes you can determine the direction of its distribution. By scratching, you can find out the relative position of the bodies during the contact, and also establish whether the destruction occurred before or after hitting the ground. Other characteristic locations may indicate traces. beats propellers, scratches from control cables t.-d. Well, all it is necessary to discover and explore.

When playing from the wreckage of the helicopter structure -can determine the cause of damage, do damage analysis. Typically, this method is applicable to the individual major nodes (blades, fuselage, control and so on. D.). In the analysis "it is of great importance to determine the nature and direction of -razrusheniya rivets, screws and bolts. "Recovery" design is photographed with her making sketches and notes for reports.

Recovery is done on a summer scene, and in the room. Before transporting the wreckage checked carefully scratches, breaks, and so on. D. On the large fragments are labeled. In the hangar to investigate -oblomkov can use frames, suspension parts, and so on top. D. We study the layout of the wreckage in the "structure" that makes it possible to determine the sequence of destruction, missing parts and helps in their quest.

On examination of the airframe, landing gear and control systems for external signs of destruction is determined by the character - before or after the impact.

One initial destruction is allocated, and then the specialist establishes the cause of this destruction (traces of fatigue failure, traces of flutter, etc.). In the fuselage, they try to determine the actual distribution of loads and analyze all cracks on the skin. An important task is to determine the directions of cracks in the skin. If it is in the form of T, then it is clear that the horizontal line appeared earlier than the vertical line. Try as far as possible to determine the direction of the forces that caused the chassis to break off. Determine the influence on the state of all components and control nodes of various factors: the installation angles, the correspondence of their positions, the installation of levers in the cabin, etc. The control levers, the linkage are inspected for the presence of bolts, lubrication, freedom of movement, Destruction.

In the study of the power plant examines the state of the engine and all its systems. The engine at the scene is subject only to external inspection. At the same time, the main attention is paid to fuel supply and regulation bodies, fuel, oil, electrical and other systems connections. If leak of oil or fuel is supposed, then color photographing is done. On the spot is determined by the time of all destruction (before or after the incident). Then the engine is sent for the necessary research to the base with an indication of the necessary tests or only disassembly and inspection. Signs of engine failure during flight are: discharge of compressor or turbine parts to the outside and melting the aluminum parts of the compressor in the hot parts of the engine running.

Before submitting the engine is necessary to determine the presence of the fuel tap and record their position, the valve found in the wreckage. Inspect fuel tanks, piping and drainage holes. Attention is drawn to the possibility of clogging, wear, holes, leaks, corrosion and so on. D. Check the documents for fuel at the last zapravke- whether condensate water, filling the entire system is checked. Chemical analysis and smear soot.

Be sure to define the active and thrust engines on impact on records recorders or to the following factors: damage to the casing of the compressor and turbine; deformations of the blade; Gauges of the engine; the actions of the pilot before impact; units of fuel supply; speed at impact.

Before finalizing the final conclusion, examine the engine and all its units. The deformed metal of the combustion chambers is studied and the temperature during the impact is determined. In the conditions of the base, functional tests of each system or individual units and elements are checked and conducted, the serviceability of the systems and their nutrition by the necessary energy before the impact is determined. The documentation on the results of the study describes the external state of all devices and assemblies, the presence of moving parts, the position of switches and controls in the cabins, the readings of all instruments. Based on the results of the survey, the required number of photographs is taken.

If a fire is suspected, it is determined whether it was in the air or on the ground. If the fire occurred in the air, you can find traces of purple. Traces of soot on the skin, under the heads of rivets and in the joints of the lining on the surface covered with soot are examined. Find traces of soot and fire running across the fracture line of the part, if parts of this part are found in different places. In the event of a fire, all pipelines of flammable liquids are checked for cracks, scuffs and other signs of unsuitable connections. Spectrograms of the investigated soot are made. If possible, it is determined whether the crew had information about the fire, whether or not to apply fire extinguishing means, whether or not the operations provided by the instruction were performed.

When the probability of an explosion establish the cause: a diversion or failure. Traces of an intentional explosion - siding torn up the outside surfaces of the cavities of the particles flying at a speed of 8-10 m / s peculiar smell for night operation and is equipped for instrument flying up.

In the US there are more than 60 Werth ports located on; roofs of buildings, but none is so high (at an altitude of 240 m) and in a densely populated area in the center Mayahettena. Landing pad it in 3 times more than Uolstrite. The cost of this port was Werth 800 thousand. USD.


Blog and articles