Those who have just embarked on a career investigating accidents in one of the transport modes (air, rail and marine) will face some tremendous challenges to perform their investigation tasks effectively. They will lack the expertise and experience to deal with the myriad of critical activities during the investigation process. Hence, unwanted mistakes may affect the credibility and effectiveness of their investigation. For this blog, I will concentrate on the air mode, but it equally applies to the rail and marine modes.

Having worked closely with experienced staff and investigators in the Cranfield Safety and Accident Investigation Centre (CSAIC), I have been able to monitor international delegates who have attended the investigation courses and this has given me a unique insight into the particular challenges that new investigators face. In this article, the focus is to develop new investigators' critical thinking by allowing them to observe and reflect on how they conduct their accident investigation tasks and to give tips on the ten most common pitfalls they can avoid during their investigation career.

1. Research – know your aircraft

It is not possible to know every aircraft’s characteristics in sufficient detail, so if there is time, a prudent investigator will research the aircraft type and its main features before arriving at the accident site. Doing advanced research by either using the internet or a readily available source, such as the excellent "Jane's All the World's Aircraft" will be time well spent. Guidance on what to study would be useful to the investigator and an appreciation that every type of aircraft will have unique challenges. For instance, researching before arriving at the accident site will assist the investigator in understanding any hazards and risks associated with an aircraft type. Once on-site, the investigator should start to identify possible risk sources. Where is the battery? Are there explosive devices present (Ballistic Parachute Recovery System or ejection seats or explosive cartridges)? Are there any stored energy devices (propeller actuators or recuperators)? Looking after yourself, your team and others at an accident site is one of the most challenging tasks for any investigator.

2. Diplomacy – be the patient diplomat

Often the investigators arrive on-site and are met by people who have been patiently (or sometimes impatiently) waiting for their arrival. The best practice that can be applied in these circumstances is to be diplomatic, explain what your role and priorities are, and be prepared to discuss issues like removing the bodies; moving the wreckage; and site security.

3. Safety – managing the risks

The investigators must be mindful of their own safety but, equally, be prepared to just get on with the job. Remaining "practical and pragmatic" at all times is very important, but practicality and pragmatism require an understanding of some complex and challenging issues. For instance, having the right level of personal protective equipment (PPE) is crucial but, sometimes, investigators fail to make sufficient progress because they have unnecessarily elected to wear too much PPE in risk environments that require just the basics of good boots and gloves.

4. Flexibility – rigid plans will fail

Perhaps the line to be drawn between a legal obligation and a matter of good practice may be explained by the requirement for flexibility. Usually, no two investigations share the same circumstances. Every accident and every accident site are different, which requires a flexible approach from the investigator. It is essential for the investigator to understand that direct teaching can only cover the basics. Investigators need to build a bank of experience and sharpen their skills by continuously expanding their knowledge through continuous professional development and learning from more senior investigators. They need to remember, flexibility will enable success.

5. Priorities – understanding what is urgent

One of the most crucial aspects is the subject of "priorities" - in essence, an appreciation of those on-site activities that can wait a while, those that can wait an hour or two, and those that have to be done as soon as is practical. This aspect is not easy for some investigators as everything seems to be an immediate priority for them. It is difficult for someone to organise themselves if they lack experience. Until they have gained experience, applying the correct priority to activities will be challenging. Investigators should, therefore, take advantage of every opportunity to develop their skills by actively participating in investigations of different events.

6. Walking the site – you can only manage what you know

The technique of walking the accident site to observe the wreckage, identify hazards, and potential evidence takes time but it is vitally important that the investigator avoids being "rushed" by other agencies on the site or under any circumstances. This also helps you plan and set your investigation priorities.

7. Preserving the evidence – think before you act

It is important for the investigator to know that if they are not sure what to do with a "find" then stop and think! Evidence can be lost by needlessly disassembling components in the field or by seeing if one fracture face fits another by trying to put them back together. Investigation finds must be harvested and handled appropriately to prevent inadvertent loss. However, some finds, such as GPS receivers and water-saturated documents, need prompt attention. Unintentional mistakes when collecting evidence will inevitably happen, but experience and best practice at the accident site will minimise this risk.

8. Photography – quality is better than quantity

Taking photographs in an orderly manner is also essential so that the investigator has an accurate and easily reconstructed set of evidential photos. It is also always important to remember to take a "context" photograph and a minimum of two other photographs of any item of interest.

9. Evidence appreciation – do not over analyse

It is necessary for investigators to gather the evidence available on-site without analysing them too much. That said, discovering one piece of evidence would enable the investigator to search for more evidence that confirms the first piece found or contradicts it. It is very tempting to analyse initial facts and form an erroneous hypothesis of the most likely cause of an accident before gathering all the evidence at the site or results from other sources such as laboratory tests. The balance of good behaviour is to encourage your findings to guide your quest for more evidence, but not to allow your initial findings to lead you to a premature conclusion on an accident’s causal factors and sequence of events before you finish examining the whole accident site.

10. Witnesses – establish rapport

It is highly likely that many investigators fail to make sufficient enquiries before they leave the accident site. Human information can be short-lived, which means if there are questions to be asked of people at the crash scene area it's best to do that before leaving the area. However, this is not always possible, so remember to ensure the witness has a good experience and will be willing to undertake a further interview - i.e. do not upset the witness!

Final thoughts

In my experience, a successful accident investigation is about far more than on-site engineering and wreckage analysis, and there is a broad range of other complementary skills that the investigator needs to learn or further develop. To do a thorough investigation, a good investigator needs to know when, how and where to apply this broad range of skills during the investigation process. Even very experienced investigators will not get it right all of the time, but a good investigator will learn from their mistakes.