I will never forget that sinking feeling in my stomach on September 22, 1991 in the Estoril pit lane as I watched Nigel Mansell’s right rear wheel detach from the FW14 right in front of me.
The wheel bounced straight towards the Tyrrell team who were readily waiting for one of their cars to come in. Luckily the wheelman that was bowled over was not seriously injured.
Ever since the 2021 Formula 1 Belgian Grand Prix a month ago, there has been greater media scrutiny on pitstops during races due to the FIA introducing a new technical directive aimed at slowing down the stops on safety grounds.
Earlier this season, during the flexible wing affair and whilst Red Bull were seemingly gaining the performance ascendancy in the period after the Spanish Grand Prix, Mercedes approached the FIA seeking clarification on technical aspects related to specific mechanisms used by other teams on their wheel guns.
The FIA’s response was to issue the new technical directive, TD22A, with the intent of reducing the risk of cars being released from the box without wheels being properly secured.
To appreciate why it was necessary to issue TD22A, it is important to understand what the final steps were in the sequence of events when changing the wheels of an F1 car before its release prior to the new TD being introduced.
In recent years it has become standard practice for F1 teams to use very light, powerful, and technologically advanced wheel guns. Each gun is connected to the pit release light system in the gantry, and a software package runs a specific algorithm that will turn on a very bright green LED on the gun when the system is satisfied that the wheel is indeed adequately secured.
When the crew member operating the gun receives that green signal, they then press a button that will signal for the jack to be released, which is then signaled to the jack person once all four buttons have been pressed. The jack signal button only becomes live in the loop once the gun LED is on, but it becomes live instantly.
Some teams, such as Red Bull, worked out that the human reaction time could be negated in signaling the jack release because the release button did not necessarily need to be pressed in sequential order after the green LED, because if it were pressed earlier, it would still register the very instant the green LED illuminated.
With the introduction of TD22A, what the FIA have done is to not only ensure that the jack release button is now sequential to the wheel secure LED, but even when it is pressed, a pre-programmed ‘human factor’ time of 0.2 seconds has been included before the signal for jack release is illuminated.
However, the perception that TD22A is specifically aimed at neutralizing Red Bull’s performance advantage in pitstops does not quite seem valid when considering the following passage from the FIA’s 2021 Formula One Technical Regulations,
12.8.4 Devices which are used to fit or remove wheel fasteners may only be powered by compressed air or nitrogen.
Any sensor system may only act passively.
In considering the very last part of the final sentence, “only act passively”, it is plainly evident that in introducing TD22A the FIA is rightly underpinning the very intent of the technical regulations.
By removing the ability to pre-press the jack release button, the system can only act passively.
Since its introduction at Spa, there have been several painfully slow stops, and some teams have directly attributed the cause to TD22A, but in time, they will all adapt. F1 will always innovate and be at the forefront of technology, and so a way will be found to reduce pitstop times even more, in good time.
Nevertheless, with the technical regulations now being bolstered by TD22A, it could only be a good thing that the risk of cars being released with a wheel not properly secured is mitigated even further.
Wheels bouncing down pit lane across a circuit of cars competing, or over the fence and into the crowd is not an image F1 wants to be associated with.