j2 AAI

Expert Witness Evidence – Providing the Data to Support The Opinion

Air Accident Expert Witness

j2 entered this area of expertise in the UK in 2015. After being applied in a precedent case in the UK, Rogers v Hoyle and subsequently Crown v Hoyle, j2 was able to apply their modelling, analysis and simulation expertise to produce scientific evidence that supported expert witness testimony. It was this case and the successful outcome that announced a new and powerful capability to the market place that benefited, Lawyers, Insurance Underwriters and Air Accident Investigators alike.


Since 2015 j2 expert witness testimony has been used in other high profile cases in the UK e.g. Crown vs Hoyle and Shoreham and Internationally in the US, where j2 software and method has since passed a Daubert challenge there.

Pre 2015, almost all expert witness evidence in air accidents was based on ‘opinion only’ evidence with little or no data provided to support said opinions. This made the process of reaching a verdict a very complicated one as one expert’s opinion countered the other but neither had any additional data or analysis to support what was presented other than the experience and credentials of the expert.

The growth in ‘opinion only’ evidence is not a surprise in that the production of data was always associated with excessive cost and time to produce. In many cases, the insurer was not willing to support that expense but neither was the court able to wait for the time needed to produce the data.

This is where j2 process and expertise was able to make a real difference, producing digital twin math models of specific aircraft in weeks not months and then being able to fly and analyse these digital twin models in the j2 software, examining and analysing any and all scenarios that could have explained the aircrafts behaviour and the resulting accident. This investigative process, based on aero engineering principles, was able to produce the engineering data to either support expert opinion or to counter it. It was as important to be able to demonstrate what didn’t happen as well as to be able to show what could have or is more likely to have given rise to an aircrafts behaviour and accident whether that be caused by mechanical failure, pilot input, weather influence, loading etc.

J2 now has a wholly reliable, repeatable and trusted methodology that can be used to produce data and expert witness evidence through the creation of digital twin models and analysis of any fixed wing or rotary wing aircraft involved in an accident. In addition, it can also add value to the following:

  • The speed with which j2 work will speed up the rate of evidence build and accelerate the submission of evidence.
  • Trusted techniques and methods open up the possibility of j2 evidence being used as a common tool for mediation purposes. Both sides would be able to run multiple scenarios and analysis reaching a consensus and also sharing the costs.
  • The production of more accurate evidence, accepted by both sides, may allow settlements to be reached earlier, reducing more costly court time.
  • The production of expert witness data could be used by insurance underwriters to establish if there are contributory factors that could impact on any award or insurance settlement values to their clients.
  • j2 digital twin creation and analysis is able to dissect opposing ‘opinion only’ evidence and determine the principles of technical argument.

j2 For Lawyers

When there is a challenge in an accident case invariably this will be settled or will end up in court. For lawyers, using j2 expert witness evidence meets their needs in a number of ways: 

  • j2 provides lawyers with an opportunity to build the strongest case they can using the latest technology within the boundaries of cost and time. 
  • j2 is able to quickly add additional scenarios and analysis quickly and easily once a model is built.
  • j2 is able to use any data or evidence produced by the other side and analyse it.
  • j2 can create simulation images(video) of the modelling and analytical work they have done.

j2 AAI is a powerful ally in the formulation of a legal action as its technical foundations in flight physics sets new standards in supporting expert witness testimony.

J2 For Air Accident Investigators

From an early stage and running in parallel with any accident investigation, j2’s Universal Tool-Kit can, in a matter of weeks, build a math model of the sample aircraft that is then used to run aircraft handling and behavioural analysis. This can accelerate investigation findings by focussing on ‘most likely’ whilst also removing from the investigation those areas shown to be `not possible’ or `highly unlikely’ to have been contributory factors from a flight physics analysis perspective. A case history is provided here for a Piper Navajo aircraft accident in conjunction with the AAIB.

At any time in this process investigators can:

  • Add fidelity to the model by including OEM or other available data e.g. flight test data, so they can continue to test out theories and hypotheses as more information becomes available.
  • Can retain the aircraft model for additional work or cases in a fully version controlled and protected database within j2. 
  • Can access and re-use the same model or have it modified to take account of aircraft variants e.g. a Beechcraft B200 will form the basis for a B200 Raisbeck model with each being fully version controlled.
  • Can add pilot or other expert opinion data/input to the analytical process and method.
  • Can use a trusted, repeatable and robust modelling methodology that can be applied and used for any fixed or rotary wing aircraft accident investigation.

J2 For Insurance Underwriters and Loss Adjusters

The j2 AAI capability is founded in a globally-leading technology that can be deployed to gain a better understanding of any possible contributors to the cause of any aircraft accident. j2 AAI can be applied from ‘scene of accident’ through the investigation process to provide supporting and trusted data and analysis to aide an insurers decisions on claims and to support and aide court proceedings as the foundation for expert witness testimony. j2 AAI enables many scenarios and outcomes to be investigated and analysed in a short space of time, contributing greatly to a better understanding of those elements of an accident that could have a bearing on the decisions made on an insurance settlement. 

J2 in Mediation

Mediation in settlement of disputed claims is a growing field and provides an alternative to pursuing an expensive and long drawn out court process. The trusted methodology in building math models of aircraft and the analysis and scenario build processes lends itself equally to be accessed and used by both sides in any mediation process. Because the j2 model and analysis data and the resulting conclusions are founded in the laws of flight physics that govern how an aircraft behaves in atmosphere, the ability to run scenarios and test all hypotheses presented by either side allows for a fair, impartial and trusted methodology to be used when reaching conclusions on the most likely outcomes based on how the aircraft actually behaves and the likely contributing factors to that behaviour.