Aircraft Accident Investigation

AST 425

Accident investigation

• Who is involved in an aircraft flight prior to an accident:

• Pilots

• Passengers

• ATC/FSS Personnel

• Airport Personnel

Accident Investigation

• After an accident this scope increases significantly:

• Site property owners• Local authorities- law, CFR(Crash/Fire/Rescue)• Medical Personnel- Coroner• Families of victims• Insurers• Aircraft owner (if not pilot)• Aircraft maintenance personnel

Accident Investigation

• Initial action at crash site:• Medical attention for any survivors• Preservation of evidence• Notification of FAA/NTSB immediately• Check for hazardous material- ie. Explosion

hazards/radioactivity• Place a guard on the wreckage- police, CAP,

volunteers etc• Protect wreckage from further deterioration• Gather names & address of eyewitnesses

Accident Investigation

• Rescue Operations:

• Injured- record positions and seat number

• Dead- leave for on-scene investigator

• Remote victims- leave a stake with name & seat number if possible (to assist in victim ID).

Accident Investigation

• Rescue Operations ctn.:

• Record any disturbance of wreckage during rescue operations

• Try not to walk or drive over the wreckage tail

Accident Investigation

• When posting any guards inform them of any hazardous materials and remote wreckage sites- identify them with stakes (even sticks)

Accident Investigation

• Duties of crash site guards:

• To protect property

• To prevent disturbance of wreckage

• Admit only authorized personnel to crash site

• Protect and preserve ground marks

• Help rope off the area

Accident Investigation

• *It is important to arrange for de-fueling of the aircraft as soon as possible to protect others at the site- local CFR personnel

Accident Investigation

• Initial action of the independent investigator:

• Secure a letter of assignment from the entity who secured the investigation (family, insurance company, etc.)

• Obtain approval from the official government investigator in charge -IIC

Accident Investigation

• Investigator duties (ctn.):• Secure the wreckage from further damage• Photograph every detail of the crash• Make sketches & measurements of wreckage &

path• Arrange for the storage of the wreckage• Arrange for expert analysis of intricate or suspect

parts• Secure witnesses statements

Accident Investigation

• Once on scene the investigator will begin making a general survey of the accident scene which will include items such as:

• Impact angle and speed (four possible)– High speed high angle– High speed low angle– Low speed high angle– Low speed low angle

Accident Investigation

• Probable flight path

• Was the aircraft under control upon impact

• Did structural failure occur prior to impact

• Was the accident survivable

Accident investigation

• In order to do this, the on scene investigator will need such items as:– Camera & flash– Tape measure– Compass– Pad/Pen– Portable GPS– Maps/charts

Accident Investigation

• Investigator equipment ctn:

• Small hand tool

• Cell phone

• Light

• Brush hacker

• 1st aid kit

Accident Investigation

• Upon completion of the general survey, the investigator will begin to focus on 4 main areas:– Recording physical evidence– Examining fire damage– Taking fluid samples– Preservation of the wreckage

Accident Investigation

• Photographs from the ground & air-• On ground begin by photographing the

perimeter of the accident every 30 degrees then moving to the cabin/cockpit to record:– Switch positions– Control handle positions– Condition of instruments– Condition of seats/structure

Accident Investigation

• Maps should have the crash site (s) plotted along with profile diagrams & sketches of the scene

Accident Investigation

• Examining fire damage- sources of ignition & combustible fluids etc.

• In-flight fire:– Soot in between the aluminum folds– Evidence of fire on downstream side of aircraft

only– Eyewitness accounts of smoke trail

Accident Investigation

• On ground fire:– Heavy soot deposits– Only metals with a low melting pt. Are melted– Flame pattern discontinuity (ie. Not trailing

along the slipstream as in flight).

Accident Investigation

• Investigator actions ctn.:– Take fluid samples (fuel, hydraulic fluid, etc.-

checking for contamination, improper servicing)

Accident Investigation

• Investigator actions ctn.:– Preserve suspect parts prior to wreckage

removal– Secure a local hangar where the wreckage can

be temporarily stored

The End

Questions?