Company Overview

A Small UK Company With a Global Footprint


j2 Aircraft Dynamics is a UK Small/Medium sized Enterprise (SME) who sells and supports its own proprietary commercial off the shelf software, J2 Universal Tool-Kit. Since the  commercial launch of the Company in January 2010, j2 has successfully grown its business around the world in the application and exploitation of its software in the fields of fixed and rotary wing modelling, analysis and simulation and in delivering substantial value return for its end user clients.

In the world of aircraft design, evaluation, modelling, analysis and simulation, j2 has remained focused on accelerating the adoption of its technology and ideas by unlocking innovation in its chosen areas of application. The unique application of the fully integrated flight physics engine within the j2 Universal Tool-Kit has also opened up further high value application areas in flight test and flight test data analysis including flight test data matching, flight test planning, flight risk/accident evaluation and analysis, accelerated design evaluations of PAV/eVTOL platforms and in the creation of high fidelity digital twins.

j2 Aircraft Dynamics Ltd initially started as a fixed wing aircraft design, modelling and analysis software business in 2004. The business continued with core software product development until the end of 2009 and in Jan 2010 it launched into a full commercial company.

Since then, j2 has built a solid technical reputation with major aircraft manufacturers covering Commercial and Military Aircraft of all sizes. The j2 Universal Tool-Kit is unique in providing a common single platform on which to use old legacy data and to model and analyse aircraft in a robust and repeatable way. The ability to use existing trusted legacy data and code and integrate this into a central consistent environment for all analysis has proven to be a hugely valuable capability and this has created a key value return through the protection and re-use of knowledge.

This capability, combined with the powerful j2 modelling and analytical tool-kit, has already yielded proven and measurable value returns for aircraft manufacturers by replacing multiple in-house tools and reducing design cycles by as much as 30%, in some cases, has been realised by companies such as Embraer and Airbus Defence and Space. The benefit of the models developed for design were then expanded through the development of a realtime simulator environment. This could enable models to be flown through basic controls or integrated into the client’s own hardware and software system through a j2 Host. The engineering simulator used at Embraer enabled them to get feedback from pilots on handling and control from very early on in the project.

Further developments of the j2 Universal Tool-Kit provides support to flight test and simulator model development through automatic flight data matching and model tuning activities. This has demonstrated a 40% reduction in effort. This has been adopted by aircraft simulator OEMs, including L3T, for flight test data matching up to and including Level-D fidelity models.

A further development built upon the solid technical background for fixed wing aircraft and evolved the capability into the rotary wing aircraft. Combining the modelling, simulator and flight test capability with rotary wing expertise enabled j2 to develop high fidelity rotary simulations. The first commercial project was the development of a Level 6 flight dynamics and engine model (FDEM) of a UH-72A (military version of the EC-145) for the US National Guard.

This ran directly on a j2 Host in the OEM simulator’s software and hardware environment. Further value has been demonstrated using the powerful flight physics engine and flight data matching capability with the company consulting in air accident investigations as expert witnesses. In the UK, j2 was involved in a landmark air accident case which saw the company and its capability presented to the world’s global aviation insurance market.

In an initial case, where the pilot was being accused of manslaughter through reckless endangerment, j2 were asked to identify what possible scenarios could have led to the accident based upon the available physical evidence. This was a precedent case where the AAIB report was cited as evidence in court. J2 was able to process multiple theories provided by the AAIB and the pilot and found that the AAIB report was wrong. The court agreed and the pilot was found not guilty. The international aviation lawyer Clyde & Co has since been a supporter of the j2 capabilities in this space with j2 acting in 4 cases globally at present and currently acting as expert in the Shoreham trial.

The j2 Universal Tool-Kit is now being used across the complete spectrum of aircraft design, development and test, covering preliminary aircraft design and analysis, flight test and flight test data matching, fixed and rotary wing simulation and air accident investigation. In all application areas there is an underlying approach of knowledge transfer, knowledge protection, training and work process improvement, all of which combine to unlock greater value returns to end user clients. This is evidenced by the process time and resource gains with Embraer and within L3T mentioned previously.

j2 Aircraft Dynamics focuses on several key application areas:


Aircraft design, modelling and analysis covering conceptual, preliminary and detailed design stages and qualification/certification and through this, knowledge protection and knowledge transfer.


Building of Dynamic Flight Models across the full fidelity range including flight test data matched models for large and small Simulator Manufacturers.


Flight test risk assessment, flight test planning and flight test data matching for high fidelity (including Level D) simulator certification and model build.


Knowledge Transfer and Knowledge Protection, combining the new with the old


Air accident analysis, reproduction and scenario investigation.

Our Mission

Our mission is to build on a Technical Leadership Position and continue to develop the definitive process for flight physics based analysis for design, simulation, and flight test/flight matching from concept through to certification.


j2 Aircraft Dynamics Ltd is a UK Company, based in the North West of England. Following the successful development of an innovative aviation concurrent analysis and design ‘Tool-Kit’ for aircraft design, this ‘new’ capability was initially demonstrated in preliminary design of the Piper Jet. j2 now sells the j2 Universal Tool-Kit into the global aerospace industry for all aspects of design, development, simulation and flight test. j2 is highly experienced in working with US Military contractors under ITAR Licenses especially in the high fidelity fixed wing and rotary fields.


The company was founded by John Jeffery in 2005 when John left BAE Systems to start pastures new. By 2009 John was introduced to Paul Jenkins. With John's technical background, Paul's experience in expanding global markets, and a mutual love of rugby, they realised it was to be an ideal team.