David Butler with Billy Monger at Brands Hatch. - 4th July 2017

In my capacity as Assessor to the MSA Medical Advisory Panel I had the privilege of meeting Billy at Brands Hatch and to undertake the assessment in order to re-instate his National A Race Licence.

In a Formula 4 racing accident at the Donington Park Circuit Billy had his left leg amputated above the knee, right leg below the knee.

Billy has yet to be fitted with his artificial legs so for the circuit test he used the innovative electronic steering wheel with full hand controls developed by Team Brit for their racing VW Evo.

Billy then took part in three track sessions (over 50 laps in total) most of which were observed by myself and Peter Alexander ARDs Chief Instructor at Brands.

Having seen his driving ability from the outset I decided to ask Peter to run an Extended ARDs test for Billy there and then.

As the VW Evo only has a single central seat, on his third session we set Billy a 10 lap stint and I climbed into the School’s Clio with Peter driving and followed him on track (one of Butler’s few perks!).

Despite Peter expertly cornering the Clio on its door handles, after 4 laps Billy was so far ahead we waited for him to lap us and followed again.

Peter stated that his driving was superb and for the first time in this car with full hand controls quite astonishing!

He exited the VW in under 6 seconds easily meeting the MSA criteria and I had no hesitation in recommending that Billy’s National A Race Licence be re-instated.

I agree with Peter, he is a very skilful driver but also an exceptional young man.

I have no doubt he will be back again to the MSA shortly for an upgrade to an International Race Licence!

AND Yes he was!

I was privileged to be asked by the MSA to report upon the modifications to a Formula 3 car for Billy to race with full hand controls and then follow up to view Billy's skill behind the wheel at his first test session.

I then wrote the following report for the MSA and the FIA with a recommendation that I had no doubt he would, with his skill and ability, be capable of not only racing the car but be highly competitive.

My report :- Billy Monger – Assessment Document

Formula 3 Race Car – Chassis Number 131

Custom Prosthetic : Extrication test : Adaptations to controls: Driver seat alteration:
Weight adjustment

Tests and examination carried by David Butler, MSA Medical Advisory Committee, on 19th January 2018 at the race workshops of Carlin Motorsport and at Bedford Autodrome on the 25th January 2018.

NB Excerpts from a technical report compiled by Sam Waple , BRDC British F3 Team Manager and Billy’s Project Manager at Carlin Motorsport are highlighted in italics.

Adaptations to Billy!

Custom Hard Socket Prosthetic

Following my initial discussions with Billy, who has exactly the same leg amputations as myself, he accepted that he would not be able to exit a Formula 3 race car in the required exit time or indeed in a safe manner whilst wearing his prosthetic legs as the ankle joints do not yield from a fixed 90 degree position.

As a consequence Billy will drive without his artificial legs. This has meant that he will use his below knee stump for braking with a custom made short hard socket fitted with a large circular rubber disc with which he will connect with a large square brake pedal which has been moved forward in the cockpit.

Accelerator and gear changing will be via controls on the steering wheel.

A hand clutch will be required for manoeuvring and for preventing the car from stalling. See more detail below.

Seat alteration


We used a bead seat for Billy in order to give him the maximum amount of support and comfort.

You can see from the pictures that we have used his left leg as support and built the seat around him which will replace the conventional heel rest.

The seat will be covered with the appropriate fabric once the initial tests have been carried out and Billy is happy with it.

As you can see we have tried to use the standard parts as much as possible to ensure equal and safe machinery. We have carried out all of the work to a very high standard and are happy that all of the modifications required for Billy to race competitively and safely are done ready for on track testing.

Adaptations to car controls

Steering Wheel

Steering Wheel

We based the steering wheel controls on what Billy had previously driven with in the fun cup car in 2017. This involved putting a throttle paddle on the left side of the wheel and eventually settling with up and down shift paddles on the right side. We came to this solution after trying many configurations in the simulator. You can see from the picture that we have included a wall in between the two shift paddles to prevent Billy selecting the wrong gear. The paddle mechanisms are standard parts for the championship just mounted on one side. Therefore they operate identically to the other cars on the grid. You will also see we have shaped the throttle paddle for Billy’s fingers to give him more feel and better location whilst in action.

You can see with the throttle paddle that it is attached to the steering wheel via two sensors. This is to ensure there is a throttle fail safe should one of the sensors go down. This prevents the possibility of a full throttle fault. The two sensors are calibrated together in order for this to work.

The steering wheel has been electrically wired through the original column loom provided by Tatuus and spliced into the chassis loom to bypass the foot operated sensors. The use of these sensors on the wheel has required MSV to remap the ECU in order for them to talk to the throttle body. However this has allowed us to retain the standard ECU and throttle body package thus ensuring the car has exactly the same characteristics as all the other cars on the grid.

Brake mechanism

Brake pedal

We decided that braking directly from Billy’s amputated leg on to the pedal using a hard socket as opposed to using a prosthetic would give him more feel and would be safer if an accident should occur. It also was a deciding factor with regards to him evacuating the vehicle in the regulated time. This involved bringing the pedal towards him up the chassis. The first step was giving a solid flat platform on which to mount the pedal base. This was achieved by fixing a 5mm carbon plate to the inside of the chassis. 5mm Carbon was chosen as this is the same thickness as the standard Tatuus chassis pedal mount face. We then fixed steel bobbins to the underside of the car to take up the honeycomb space between skins of the original chassis. This gave us the strength required to mount a brake pedal through. All of the work was carried out in house by our qualified carbon specialists.

For the pedal base itself we decided to buy a product straight off the shelf to ensure that it had gone through all the necessary safety inspections required for motorsport.

We chose a product from Tilton Racing as it allowed us to use the original master cylinders and bias cable supplied with the car. Once again this ensures the car is the same specification as all the others on the grid.

One last modification to do once we are happy the pedal is in the correct place is to move the brake fluid reservoirs externally to the front of the chassis. This will be done prior to racing.

Clutch mechanism


For the clutch we opted for a hand control lever on the right hand side of the chassis. The mounting point for the level has been secured using the same procedure as the brake pedal bobbins. It has been made as flush to the side of the chassis as possible to ensure minimal intrusion to Billy’s driving space whilst not in use. It is now cable operated to a mechanism shown in the picture that allows us to use the original master cylinder and complete clutch package supplied by Tatuus. All of the work has been carried out by our in house machinist.

Weight adjustment

The F3 car has been weight at the front end to compensate for the weight of Billy’s missing limbs. i.e. Billy’s original weight prior to the accident less his current weight. The car was then corner weighted and balanced with Billy insitu. No weight advantage has been gained!

Extrication test

Billy, kitted out in his full race clothing and helmet, extricated himself from being fully strapped in to being seated on the floor alongside the car in 4.7 seconds thereby easily meeting the MSA’s exit criteria of 7 seconds.

A successful and very enjoyable day at Carlin Motorsport followed by an exciting first day for Billy in the car at the Bedford Aurodrome. Photo below in the pit garage with Billy.

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