~ Aviation Management ~

ERAU MOOC - Aircraft Accident Investigation

The agency often delegated to conduct field investigations of non-fatal US General Aviation aircraft accident is the FAA. 

The NTSB's 5 member safety board makes the final determination for probable cause and aviation safety recommendations in the US.

To assist in civil litigation is not a reason that the NTSB investigates aircraft accidents.

Poor training is a precondition for unsafe acts.

FAA Advisory Circular AC 60-22 and many training programs focus on 5 hazardous attitudes because they contribute to poor judgment (antiauthority, impulsivity, invulnerability, macho, and resignation).

According to James Reason, "Errors made by skilled experts are not root causes of accidents but symptoms of the flaws and inherent limitations of the overall sociotechnical system in which these experts work." This refers to how there are generally not root causes that are attributable to human error, and that human error itself is not the root cause. 

Military aircraft accidents are generally not a responsibility of the NTSB mission to determine the probable cause. 

A survivable aircraft impact is one during which the declaration forces transmitted to the occupants did not exceed human tolerance and in which the structure surrounding the occupants (occupiable living space) remained substantially intact.  

Pressure vessels - tires, fire extinguishers, and accumulators

Pyrotechnic - ejection seats, munitions, ballistic parachute systems and survival equipment

Fumes, dust, and vapors - result from burning of composite and synthetic materials 

Hygiene - blood borne pathogens

Mechanical - springs, landing gear door, and drag chutes

Chemical - fuel, hydraulic fluid, oxygen tanks, and oil

Stall/Spin Impacts - essentially low velocity/high angle impacts with rotation at moment of crash

High Velocity/High Angle - described as the proverbial 'smoking hole', the aircraft created a deep hole

Low Velocity/Low Angle - the aircraft may have bounced, hit again, and bounced several times

Low Velocity/High Angle - the impact crater will be shallow and the aircraft will be largely intact

High Velocity/Low Angle - wreckage is spread across a large area of land identified by an initial impact scar followed by a fan shape distribution of wreckage

The purpose of the CREEP model is to assist in the investigation of all aspects and phases of accident survival. 

Structural investigators are generally responsible for documenting pre-impact strikes on surrounding obstacles, documenting fire patterns and damage, and documenting wreckage distribution. 

Major ground scars (direction, length, depth, etc.) and obstacles struck could be important factors to structural damage.

Systems investigators should use schematic diagrams from applicable manuals to document components and systems as they are identified. 

Systems investigators should be aware that emergency responders (e.g., Airport Rescue Firefighters) could have inadvertently changed cockpit switch settings during occupant extrication.

The Flight Data Recorder (FDR), when equipped, is essential to the work of investigators, as it records many different operating functions of a plane, such as the time, altitude, airspeed and direction the plane is heading. 

The fire tetrahedron includes; heat source, fuel source, chemical chain reaction of other components, and oxidizing agent. 

If the Cockpit Voice Recorder (CVR) is recovered in water, it should immediately be packed in water (fresh, if possible) and not be allowed to dry out.