Thursday, May 1, 2008
Anatomy of an Investigation
You are relaxing in the pilot lounge waiting for passengers to arrive when you see on TV "Breaking News" — an aircraft has crashed. You see overhead pictures from news helicopters, the FAA or NTSB investigators on the way to the crash site, and finally someone talking about aviation safety.
Many pilots have often wondered what really happens during an investigation. The FAA, National Transportation Safety Board, and the military each have their own procedures for an investigation, but all have things in common. An investigation’s purpose is to find out what happened, why, and what can be done to prevent it from occurring again.
I’ve spent many years promoting safety and investigating accidents, having been trained by the U.S. Army and the FAA. The most satisfying aspect of these investigations is arriving at recommendations that will reduce risks and avert future accidents, thus saving lives and conserving resources.
In the case of large aircraft accidents or ones with significant public interest, the NTSB will normally launch a "Go Team," with an investigator-in-charge leading the team. When smaller aircraft are involved, the NTSB may not respond but rely on the FAA to investigate.
When a military aircraft is involved with a civilian one, the FAA or NTSB takes the lead, with the military working alongside as a member of the team. Sometimes the military will conduct its own probe, too.
If the mishap involves only military aircraft, the FAA and NTSB don’t get involved unless the military asks them to. Sometimes the military will tap the NTSB’s technical abilities to aid in gathering information, for instance by deciphering flight data or voice recorder informations.
The team will initially meet at the crash site and begin to organize and discuss the tasks before them. They will quickly need to organize a work area. Each member is an expert in their respective areas. The investigator-in-charge or board president guides and leads the investigation, setting rules and goals, delegating duties, and establishing schedules for briefings.
Each member plays an important role in the outcome. Members may include representatives of the operators and the aircraft and engine manufacturers, an instructor pilot and a maintainer experienced in the aircraft type involved, medical personnel, the company safety officer (if there is one), and a records keeper.
The team will focus on three contributing-cause aspects: material failure, human error, and environment conditions. Each should be looked at intensely. Human error, the leading cause of most aviation mishaps, can be any human factor that contributed to the mishap — scheduling or dispatch, maintenance, or error by the crew members.
The maintenance team will look at the aircraft’s maintenance and weight and balance records, assess damage, and check fuel, hydraulic fluid, and oil samples. They will also look at whether systems were operating as designed prior to impact.
The human-factors team consists at a minimum of a pilot or flight instructor rated in the mishap aircraft and a flight surgeon (or a psychologist or human-factors expert on the civil side). It will look at pilot and ATC logs, medical files, and the crewmember daily activities leading up to the crash. Known as the 72-hr autopsy for fatal accident probes, this activities review includes sleep habits, diet, and personal or financial issues.
The human-factors team also reviews environmental conditions and training records and normally interviews witnesses.
The investigation is normally conducted in three phases: information gathering (which is normally the longest), analysis, and deliberation.
Information gathering involves the relentless, sometimes tedious tasks of uncovering all aspects of the mishap. Once the team determines all pertinent information has been gathered, it moves on to analysis.
During this phase, investigators look at the information gathered to develop a timeline of events leading to the mishap. They will decide on what information will be the focus of the deliberation phase.
That phase is when information and analysis is discounted or kept for further discussion in the search for contributing factors. After these factors are discussed, they are organized and reviewed for recommendations. When the factors gathered in the investigation are considered to be present and contributing, recommendations are made to prevent further mishaps and forwarded to the appropriate agencies for review and implementation.
In conclusion, we can use the investigation process and the team recommendations to help us with our risk-management process to reduce accidents. When pilots, maintenance and flight operations personnel use the risk-management process, they reduce the probability of having to participate in an investigation where they are the main characters.